Python error opening plugin manager in Quantum GIS

I just attempted to update my version of QGIS from something like 2.2.0 (can't remember exactly what it used to be) to 2.6.0 and now encounter an error - copied below - when I try to open the Plugin Manager/Installer.  I uninstalled my previous version of QGIS first and, in addition to QGIS 2.6.0, downloaded the latest versions of Python, NumPy, matplotlib, and GDAL as recommended on the site.  I've tried reinstalling older versions of QGIS again, but the error pops up all the time now.  Sadly, I wanted to update the program in order to access the latest plugins.  I'm on Mac OS X 10.8.5.  An error has occured while executing Python code:   Traceback (most recent call last):   File "/Applications/QGIS.app/Contents/MacOS/../Resources/python/pyplugin_installer/installer_data.py", line 460, in xmlDownloaded     if isCompatible(QGis.QGIS_VERSION, qgisMinimumVersion, qgisMaximumVersion):   File "/Applications/QGIS.app/Contents/MacOS/../Resources/python/pyplugin_installer/version_compare.py", line 188, in isCompatible     if len(maxVer)TypeError: object of type 'NoneType' has no len()   Python version: 2.7.9 (v2.7.9:648dcafa7e5f, Dec 10 2014, 10:10:46)  [GCC 4.2.1 (Apple Inc. build 5666) (dot 3)]   QGIS version: 2.6.0-Brighton Brighton,   Python path: ['/Applications/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing', '/Applications/QGIS.app/Contents/MacOS/../Resources/python', u'/Users/Lucy/.qgis2/python', u'/Users/Lucy/.qgis2/python/plugins', '/Applications/QGIS.app/Contents/MacOS/../Resources/python/plugins', '/Library/Frameworks/SQLite3.framework/Versions/C/Python/2.7', '/Library/Frameworks/GEOS.framework/Versions/3/Python/2.7', '/Library/Python/2.7/site-packages/numpy-override', '/Library/Python/2.7/site-packages/matplotlib-override', '/Library/Frameworks/GDAL.framework/Versions/1.11/Python/2.7/site-packages', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python27.zip', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages', '/Library/Python/2.7/site-packages', '/Users/Lucy/.qgis2/python/plugins/mmqgis/forms', '/Applications/QGIS.app/Contents/Resources/python/plugins/fTools/tools']


Prove that  $$C^n_1 + 2\times C^n_2 + 3\times C^n_3 + \dots + n \times C^n_n = n\times 2^{n-1}$$ I tried the formula  $$C^n_1 + C^n_2 + \dots + C^n_n = 2^n$$ Then , mutiply both sides by $$n$$ $$n\times C^n_1 + n \times C^n_2 +\dots +n\times C^n_n = n\times 2^n$$ I tried to show that the left hand side equals  $$2(C^n_1 + 2 \times C^n_2 + \dots + n\times C^n_n )$$ To get the required but i could not get it ?


Is it possible to have my account frozen?

I know this sounds really weird, but I don't want access to my Stack Exchange account for a while, but I would like to keep it to use in the future. Is it possible for the SE team to freeze my account?  It is like this: I like SE. I am beginning to feel I like it a bit too much. In order to make sure that participating on SE does not have a negative impact on other priorities, I have decided to put my activity on hold. This brings me to a position in which it is a choice between having my account frozen somehow, or deleting it. I really don't want to delete my account, as I have just made it over 2k rep; I would lose all of my rep, badges and privileges, and have to start all over again from scratch.  That brings me back to the question: Is there any way possible to have my account locked or frozen?


Before the upgrade I was using gnome on Ubuntu 16.04 with lightdm and it worked fine. After upgrading to Ubuntu 18.04 I switched to gnome gdm3. On the first day I could login to my user account, configure gnome and so on. However on the next day when I tried to login for the first time, the login screen just comes back again and when I try it for a second time it just freezes. Can someone help me with this problem?  In advance thanks for help.  UPDATE: I switched back to lightdm and it works just fine. However I would still like to use gdm3 because I like it more. How could I do this?


TV documentaries invariably show the Big Bang as an exploding ball of fire expanding outwards. Did the Big Bang really explode outwards from a point like this? If not, what did happen?


Include tex-files and compile separately

For a large project, I'd like to write each chapter on it's own. After that, I'd wish (of course) to incorporate all the chapters in a base document (the large project). I've heard ob \include and \input, but they don't seem to do what I'm searching for:   Is it possible to include/input only the part between \begin{document} end \end{document} of the chapter files, so that it's possible to compile the chapter files separately (to be able to check and work on the chapter file) before compiling it in the base document? I know this would be possible by simply deleting the preample of the chapter files, but with a dozen of chapter files, I prefer an automated way (if possible). Is it possible to make references to \label and \ref between different chapters, using different chapter files?


How much power is really wasted by a wall wart?

The title pretty much sums it up... Hyperbole aside, how much actual power is consumed by a typical wall wart when the device it's attached to isn't powered on? And are there designs for wall warts that minimize or eliminate this sort of parasitic load?


On Liouville numbers and the Continuum Hypothesis

Collecting some theorems from the book  by its authors, there is some inconsistency, I think... :   i. $L= \sum_{n=1}^{\infty} 10^{-n!}$ is transcendental.   ii. Numbers of the form $\sum_{n=1}^{\infty} a_n 10^{-n!}$ in which $a_i \in {\{0,1}\}$ are Liouville  numbers and thus transcendental. So, by Cantor diagonalization argument there are uncountably many Liouville numbers.    iii. The collection of all Liouville  numbers has measure zero. The set of all sequences of zeros and ones (not all zero) are in 1-1 correspondence with $(0,2)$ and this is in 1-1 correspondence with $\mathbb{R}$.   How an uncountable subset of $\mathbb{R}$ has measure zero?


For complex numbers $a,b,c$, explain why $a^{b\cdot c}=(a^b)^c$ is not   necessarily true.   I know that complex powers are really sets of complex numbers.  But coming from real analysis the above seems confusing.  Can anyone give a simple explanation of what is going on.


Why is nls() giving me "singular gradient matrix at initial parameter estimates" errors?

I have some basic data on emission reductions and cost per car:  q24 <- read.table(text = "reductions  cost.per.car     50  45     55  55     60  62     65  70     70  80     75  90     80  100     85  200     90  375     95  600     ",header = TRUE, sep = "")   I know that this is an exponential function, so I expect to be able to find a model that fits with:      model <- nls(cost.per.car ~ a * exp(b * reductions) + c,           data = q24,           start = list(a=1, b=1, c=0))   but I'm getting an error:   Error in nlsModel(formula, mf, start, wts) :    singular gradient matrix at initial parameter estimates   I've read through  on the error I'm seeing and I'm gathering that the problem is probably that I need better/different start values (the initial parameter estimates makes a little more sense) but I'm not sure, given the data that I have, how I'd go about estimating better parameters.


Why don't we use closed covers to define compactness of metric space?

I'm a beginner in metric space. So many books I've read, there is only the notion of open covers. I want to know why do we worry about open covers to define the compactness of metric spaces and why don't we use closed covers? What is the problem in defining closed cover of a set? Can we use the alternative definition of compactness: "Every closed cover has a finite subcover"?


Sorting an Array That has Dictionary Values

I am storing some calendar items in an array like so,  [  {'CALENDAR': 'HOME',   'SUMMARY': vText('b'Run''),   'LOCATION': vText('b'''),   'START': datetime.datetime(2017, 9, 29, 18, 0, tzinfo=<DstTzInfo 'US/Pacific' PDT-1 day, 17:00:00 DST>),   'END': datetime.datetime(2017, 9, 29, 18, 45, tzinfo=<DstTzInfo 'US/Pacific' PDT-1 day, 17:00:00 DST>)},  {'CALENDAR': 'HOME',   'SUMMARY': vText('b'Tacos''),   'LOCATION': vText('b'''),   'START': datetime.datetime(2017, 10, 2, 19, 0, tzinfo=<DstTzInfo 'US/Pacific' PDT-1 day, 17:00:00 DST>),   'END': datetime.datetime(2017, 10, 2, 20, 0, tzinfo=<DstTzInfo 'US/Pacific' PDT-1 day, 17:00:00 DST>)},  {'CALENDAR': 'WORK',   'SUMMARY': vText('b'Work''),   'LOCATION': vText('b'3740 West Market Center Drive\\, Riverton\\, UT\xc2\xa0 84065''),   'START': datetime.datetime(2017, 8, 21, 8, 0, tzinfo=<DstTzInfo 'America/Denver' MDT-1 day, 18:00:00 DST>),   'END': datetime.datetime(2017, 8, 21, 17, 0, tzinfo=<DstTzInfo 'America/Denver' MDT-1 day, 18:00:00 DST>)}  ]   I am wondering if there is a way that I can sort the array by the dictionary value 'START' so that the earliest event is listed first in the array and I can print the information I want to from there, any thoughts?


How to create a Telephone Directory using a CSV data base

I have created a excel file with Name,Title,Designation,Department,Faculty,Institute,TelNo,Email id columns I want section wise telephone directory, i.e., We have 16 Faculties. So I want to create a Chapter/section title such as "Faculty of xyz" and under it Section or Subsections like "Department of abc" and below it the names of faculty members with their telephone numbers. Is it possible to create such a Directory?


How to extract expanded equations that use commands?

I have a document with a lot of equations that use commands to maintain consistency. For example, it looks like this  \documentclass{article} \usepackage{amsmath}  \newcommand{\numberOfDocuments}{\mathcal{N}} \newcommand{\someSimpleCommand}{\mathcal{F}} \newcommand{\someComplexCommand}[1]{\sum_{i = #1}^{#1+5} i}  \begin{document}  This is $\numberOfDocuments = 1$ document with equations \begin{align} \someSimpleCommand \approx \someComplexCommand{\numberOfDocuments} \end{align}  \end{document}   In order to use the resulting equations for example at MathOverflow or other places where I can not provide a complex document, I want to extract the plain TeX equations like  \mathcal{N} = 1 \mathcal{F} \approx \sum_{i = \mathcal{N}}^{\mathcal{N}+5} i   Is there any way to do this? Is there maybe an intermediate step in the LaTeX compilation process that I could access? It does not really matter if I get the whole document with the expanded equations or only the equations itself.


What kind of beings are shown by the Marauder's Map?

The map definitely shows people (humans) inside the castle But I remember reading Harry watching Peeves bouncing around in the trophy room and Peeves is not human And I don't remember if I had exactly read it or not, but  says that it shows the ghosts as well So what kind or creatures or beings come under the map's radar? Any living creature? Or humanoids? Or creatures with a significant size or intelligence? Would it show the house elves in the kitchen, centaurs in the forests and the merpeople in the lake as well? What about the giant squid and the thestrals or unicorns? Would it have shown the troll from the Philosopher's stone if they had the map then? What about Quirell/Voldemort? Would he have shown up on the map? And the basilisk from the chamber of secrets (the book)? May be the chamber itself was unplottable but if the map could show the basilisk he would have been visible when he was slithering around in the pipes.


Proving that P/PJ is a projective right module over R/J

If P is a projective right module over a ring R  and J is a two sided ideal of R.  Prove that P/PJ  is   a  projective right module over R/J  .  My idea was trying to proof that " $M$ is an $R$-module iff  $M$ is an module over $R/J$ " where J is an ideal of R .


How do I calculate $A=UL$ factorization where $U$ is upper triangular matrix with 1's along the diagonal and $L$ is lower triangular matrix?   How is this similar to the $LU$ factorization?


Java: Hibiscus Walk Hotel & Spa Software Development Project

I have some problems here. I want the program to give me my total bill when I press N but it keeps asking the same question over and over again. When I press Y, it gives basically does the same thing again.  Also, how can I show the amount of change the person should get back? Example: If the 2 items cost $5 and the person pays $10, I would like it to say Your change is $5.  Thank you.   String temp = null; temp = JOptionPane.showInputDialog("Enter The amount of Items :"); int Size = Integer.parseInt(temp); String[] ItemName = new String[Size]; Integer[] ItemId = new Integer[Size]; Double[] ItemPrice = new Double[Size]; Integer index = 0;  while (index < Size) {   ItemName[index] = JOptionPane.showInputDialog("Enter The Item Name:");   temp = JOptionPane.showInputDialog("Enter Item ID for " + ItemName[index] + " :");   ItemId[index] = Integer.parseInt(temp);   temp = JOptionPane.showInputDialog("Enter The Price " + ItemName[index] + " :");   ItemPrice[index] = Double.parseDouble(temp);   index++; } for (int i = 0; i < Size; i++) {   System.out.printf("%s\t %d\t %.2f\t\n", ItemName[i], ItemId[i], ItemPrice[i]); }  surName = JOptionPane.showInputDialog("Please enter your surname");  number = JOptionPane.showInputDialog("Please enter the Amount Paid: "); amountPaid = Double.parseDouble(number);  System.out.println("Your surname is " + surName); System.out.print("Enter the Item ID for the item"); compare = keyboard.nextInt(); while (Complete == false) {   while (a < Size) {     if (compare == ItemId[a]) {       Price = Price + ItemPrice[a];     }     a++;   }   System.out.print("Sale Complete? Enter Y or N");   response = keyboard.next();    if (response == "Y") {     System.out.println("The toal bill is" + Price);   } else {     System.out.print("Please answer the following: ");   } }


How to display the normal values of a face?

I want to know the orientation of a certain face by knowing the z vector(direction vector) of its normal. How do I let Blender display the values of the normal of a face?


If I can't flag a post, don't wait until after I've typed an explanation to tell me so

I flagged a post today, typed out a fairly thorough explanation, clicked the button... and got told that I'd already flagged this post (for something else, which I'd forgotten about) so this flag wasn't allowed.  (This happens if the first flag is still active.)  The dialogue with my explanation was gone at this point, so if I wanted to communicate with the moderators about that, I was going to have to start over.  (In case you're wondering how this could happen, one flag was related to the post itself and one was related to the user -- there being no way to flag a user directly, you have to hang it off of a post.  But I've also seen this with cases where the first flag hangs around unhandled for a week or two and I've forgotten about it.)  Since the system is going to detect that I've already flagged a post and reject a second flag, can it do that after I click the "flag" link instead of waiting until the end of the process?  (Or gray out the link so I can't click it in the first place?)  2015-12-18: someone suggested to me in chat today that this had been implemented, so I tested again.  The behavior has not changed: I flagged a post using "other", then flagged it again (also "other") before the first flag was handled, and the flag was rejected only after I'd typed the message.  (I did this on a site where I'm a moderator so I could then clean up after myself.)


What source address should I enter in the img tag?

I want to enter an image in the Stack Overflow platform. I have an image on my C drive which I want to add in my question. How can I add this image?


Calculate the limit of $\sqrt{n^2-3n}-n$ as $n \rightarrow \infty $.  I'm having a hard time trying to simplify this expression in order to be able to get the limit of it.  I have $\sqrt{n^2-3n}-n=\sqrt{n^2(1-\frac{3}{n})}-n=n\sqrt{1-\frac{3}{n}}-n=n(\sqrt{1-\frac{3}{n}}-1)$  Don't think that this gives me anything useful, can anybody give me some hints.


I have a excel having data like below:  Data.xlsx  Method_Name | Argument_01 | Argument _02 Func1       | val1        | val2 Func2       | val3        | val4   Now my question is:  How to read the function name and arguments from Data.xlsx file and invoke the method Func1 and pass the arguments (val1,val2) using python?  If provide me a code on that using python it would be very very helpful for me.  Thanks.


I want to be able to run all of my Steam games on my laptop.  But 2/3 of them are .exe files.  Is there a way to run or convert them as/to .deb files?  Or is there a program that will help me run them?


MySQL not inserting data from Eclipse to database

I have a problem with data not uploading to database. I tried everything and looked into serveral tutorials on YouTube but none worked. Error From Console:  Code: if(args[0].equals("report")) {                 StringBuilder message = new StringBuilder();                 for(int i = 0; i < args.length; i++) {                     message.append(args[i]).append(" ");                 }                     PreparedStatement ps = null;                 try {                     ps = MySQL.con.prepareStatement("INSERT INTO `sawio`(`admin`, `reciever`, `priority`) VALUES (?,?,?)");                     ps.setString(1, p.getName());                     ps.setString(2, p.getDisplayName());                     ps.setString(3, p.getCustomName());                     ps.executeUpdate();                     p.sendMessage("OKOK");                     p.sendMessage("PL");                 }catch(SQLException ev) {                     ev.printStackTrace();                 }             }             return true;         }


When is a sum of consecutive squares equal to a square?

We have the sum of squares of $n$ consecutive positive integers: $$S=(a+1)^2+(a+2)^2+ ... +(a+n)^2$$ Problem was to find the smallest $n$ such, that $S=b^2$ will be square of some positive integer. I found an example for $n=11$. Now, I'm trying to prove, that if $2<n<11$ there is't any solution. So I need some help with this: If $n,a,b \in \mathbb{N}$ and $n<11$ prove that equation  $$ n\cdot a^2 + n(n+1)\cdot a + \frac{1}{6}n(n+1)(2n+1)=b^2 $$  can't be solved. Or if I'm wrong, find counterexample.  The only idea I have is: to consider the remains $\operatorname{Mod}[b^2,n]$ and $\operatorname{Mod}[\frac{1}{6}n(n+1)(2n+1),n]$. For each $2<n<11$, but it is very long.


problem to burn windows 10 on flash drive using woe usb

how to solve this problem?   Installation failed! Exit code: 256 Log: WoeUSB v@@WOEUSB_VERSION@@ ============================== Mounting source filesystem... Error: File "/media/woeusb_source_1551398248_10268/sources/install.wim" in source image has exceed the FAT32 Filesystem 4GiB Single File Size Limitation and cannot be installed.  You must specify a different --target-filesystem. Refer: https://github.com/slacka/WoeUSB/wiki/Limitations#fat32-filesystem-4gib-single-file-size-limitation for more info. Unmounting and removing "/media/woeusb_source_1551398248_10268"... You may now safely detach the target device


Number between less than 15 or equal to 15 or between the two options?

Is $14.9999999$ ad infinitum $\lt 15$, $= 15$, or in between?


Building machine learning models to do forecast, sometimes the dataset was used is imbalanced, and there are some methods to deal with this issue such as the resample method and choose other metrics(for example, recall rate) rather than accuracy. So can these two methods be used at the same time? Or just one method would be fine to solve this imbalanced data issue. Are there any pros and cons of each method?


what contact, if any, did Owen and Beru Lars have with Obi-Wan?

In Star Wars, Episode 4, Owen Lars appears to be mistrustful of Obi-Wan.  I presume he knows who Luke's father is, and obviously Obi-Wan is the one who drops off Luke with Owen and Beru.  Is there any information on the relationship between the Lars' and Obi-Wan on Tatooine?  I suppose the real subtext of this question is:  What is it that caused Owen to be mistrustful?  Was it just out of fear for Luke, knowing what Obi-Wan planned for him as part of the rebellion, or was there anything in their history, post Episode 3, that explains it?


How do I change the top bar font in GNOME 3.30.1?

I am desperately trying to change the font of my top bar, but editing the gnome-shell.css in my currently installed theme (Canta-dark-square) does not work somehow. My .themes folder is in the /home/my_name/ directory.  What am I doing wrong?


Every infinite subset of a compact space has an accumulation point. I understand the reciprocal does not hold for every topological space, but I cannot manage to find a counterexample. Any ideas?


I have roughly 200 blogs in my drupal website. Are they able to auto post to instagram? When I create new blog, is it able to post to instagram? If yes, how to do it? Many Thanks.


Started earning money, have significant savings, would like to invest

I am in the last year of university and got myself a well paid part-time job. My expenses are negligible for now. Since I was 18 I was always making money here and there, so I managed to gather over 400k of local currency,CZK (200 on my personal account, 200 on "building savings"(?)). Now I've been doing a little research for the last couple of days so I've got an idea what I could do with the situation, but the world of finance is absolutely alien to me, big and scary so I would seriously appreciate a feedback and some advice. My idea would be to take most of the saved money and put it into ETF as a long-term investment, such as VOO or SPY, which might be a less dangerous option. From this point I'd like to regularly, monthly, save up. My question is: is this a smart idea, or are there any flaws I don't see. I'd like to see this as a passive, long term investment. Right now I am sitting on two chairs at once and I don't have the time to learn enough and watch enough the world of finance to start actively working with money. I am aware of generally known risks about ETF, that it is a bit more risky than other options etc. Another question: what would be the procedure, is it really that easy to create an account with a broker (xtb,etoro), put the money there and immediately buy? Is this reliable? Now for some this probably is the very basic question, but I really have got no one to ask around and as well as I know that it is the better the sooner you start with saving, I am also aware that it might be a bad idea to rush into things and regret in a week or two after finding out and realizing mistakes I don't see. Edit: naturally I am curious about another suggestions that would you see as a better option


How to upgrade/downgrade a specific package from "sid" on debian jessie "stable"?

I need to upgrade some specifics packages from sid on debian jessie stable with their dependencies.  By adding  the following repo :  deb http://ftp.fr.debian.org/debian/ sid main deb-src http://ftp.fr.debian.org/debian/ sid main deb http://ftp.fr.debian.org/debian/ sid main contrib non-free deb-src http://ftp.fr.debian.org/debian/ sid main contrib non-free   to my sources.list, all the existing packages will be upgraded and can damage my system.  How to install a specific package from "sid" on debian jessie "stable"  without breaking my existing system ?  Edit  How to set the pin-priority  to upgrade ? and how can it be used to downgrade a specific package when something went wrong ?


Theorem/Definition/Lemma problem --- Numbering

I am trying to work on the numbering of the theorems/definitions/lemmas etc., and I have some problems with the numbering.   I would like the theorems, propositions, corollarys, definitions, conjectures, examples to follow the same numbering, and to reduce the numbering. For example, in my code below, the stuff goes as follows:     Chapter 1      Addition      1.1 Basics (SECTION)      Definition 1.1.1.      Theorem 1.1.1.      Theorem 1.1.2.      Example 1.1.1.      1.1.1. Some tips (SUBSECTION)      Definition 1.1.2.      1.2 Advanced stuff (SECTION)      Definition 1.2.1.   But how would I get it to be like this below?:     Chapter 1      Addition      1.1 Basics (SECTION)      Definition 1.1      Theorem 1.2      Theorem 1.3      Example 1.4      1.1.1. Some tips (SUBSECTION)      Definition 1.5      1.2 Advanced stuff (SECTION)      Definition 1.6   And for each new chapter, how would I get the numbering to be resetted? Like it would be Definition 2.1, Theorem 2.2, Theorem 2.3 for chapter 2.  I like the layout of my table of contents, i.e. Part I is addition and subtraction, Part II is Multiplication and division, and I am happy with the way the sections and subsections are working, but I just want to definitions, theorems etc. to be corrected.  \documentclass[11pt,a4paper]{report} \usepackage{amsmath,amsfonts,amssymb,amsthm,epsfig,epstopdf,titling,url,array}   \theoremstyle{plain} \newtheorem{thm}{Theorem}[section] \newtheorem{lem}[thm]{Lemma} \newtheorem{prop}[thm]{Proposition} \newtheorem*{cor}{Corollary}  \theoremstyle{definition} \newtheorem{defn}{Definition}[section] \newtheorem{conj}{Conjecture}[section] \newtheorem{exmp}{Example}[section]  \theoremstyle{remark} \newtheorem*{rem}{Remark} \newtheorem*{note}{Note}      \begin{document} \tableofcontents  \part{Addition and Subtraction}  \chapter{Addition} \section{Basics} \begin{defn} Here is a new definition \end{defn} \begin{thm} Here is a new theorem \end{thm} \begin{thm} Here is a new theorem \end{thm} \begin{exmp} Here is a good example. \end{exmp} \subsection{Some tips} \begin{defn} Here is a new definition \end{defn} \section{Advanced stuff} \begin{defn} Here is a new definition \end{defn} \subsection{Warnings} \begin{defn} Here is a new definition \end{defn}  \chapter{Subtraction} \section{Basics} \subsection{Some tips} \section{Advanced stuff} \subsection{Warnings}  \part{Multiplication and Division}  \chapter{Multiplication} \section{Basics} \subsection{Some tips} \section{Advanced stuff} \subsection{Warnings}  \chapter{Division} \section{Basics} \subsection{Some tips} \section{Advanced stuff} \subsection{Warnings}    \end{document}


Changing title and options in javascript confirm dialog

I want to add my project title to a javascript confirm dialog, and want to change "Ok" and "Cancel" to "Yes" and "No". How can I do this?


Connecting external display to Early 2015 MacBook Pro

Does Early 2015 MacBook Pro output 4K 3840 via Mini DisplayPort to DisplayPort? I seem to get only HD max option on YouTube videos.  I have a Samsung U32J590U 31.5" 4K UHD monitor. If not, do I have to get a real Thunderbolt cable or is HDMI-to-HDMI the answer?


So I am plugging along quite happily on my new Linux (Ubuntu) box when suddenly my root password has ceased to work.  I get one of two errors:    "Your authentication was unsuccessful. Please try again." or "___ is not in the sudoers file.'   This literally happened while I was using the computer. One minute it works fine, the next it doesn't.  I can't edit the /usr/sbin/visudo file because sudo won't accept my password.  There has only ever been one user account on this computer and I have never changed a password. What can i do to fix it?


How to prove $\sum\limits_{r=0}^n \frac{(-1)^r}{r+1}\binom{n}{r} = \frac1{n+1}$?

Other than the general inductive method,how could we show that $$\sum_{r=0}^n \frac{(-1)^r}{r+1}\binom{n}{r} = \frac1{n+1}$$  Apart from induction, I tried with  to check the validity, but I can't think of an easy (manual) alternative.  Please suggest an intuitive/easy method.


Building $\mathfrak{so}(1,3)$ reps using $\mathfrak{so}(1,3)\cong \mathfrak{su}(2)\oplus \mathfrak{su}(2)$

I'm going through the representation theory of $\mathfrak{so}(1,3)$, building Dirac/Weyl spinors and vectors, and I'm a bit confused on the mathematical definitions involved. We have $\mathfrak{so}(1,3)\cong \mathfrak{su}(2)\oplus \mathfrak{su}(2)$ as algebras. I'm good with the formalities of this isomorphism: if $J^i$ and $K^i$ are our elements of the six-dimensional algebra $\mathfrak{so}(1,3)$, we can always write any linear combination of $J^i$ and $K^i$ as $a_i J_+^i+b_jJ_-^j$ where $J_+$ satisfies its own $su(2)$ algebra, $J_-$ does too, and all $J_+$ and $J_-$ commute.  To build out a representation of $\mathfrak{so}(1,3)$, I see the notation $\left(n_1,n_2\right)$ used. So $\left(\frac{1}{2},0\right)$ can denote the left-handed Weyl spinors, $\left(0,\frac{1}{2}\right)$ the right-handed ones, $\left(\frac{1}{2},\frac{1}{2}\right)$ vectors, and $\left(\frac{1}{2},0\right)\oplus\left(0,\frac{1}{2}\right)$ Dirac spinors. I'm a bit confused about what this notation really means.  It can't be the tensor product: $\frac{1}{2}\otimes \frac{1}{2}\cong 1\oplus 0$ is still just a representation of the three-dimensional Lie algebra $su(2)$, with group action (for example) $J^i=(\frac{1}{2}\sigma^i)\otimes 1+ 1\otimes (\frac{1}{2}\sigma^i)$.   Is the following a good definition for $(n_1,n_2)$?  Take $V_1$ to be the vector space of the spin $n_1$ representation, and $V_2$ the vector space corresponding to $n_2$. Then $(n_1,n_2)$ is the representation of $su(2)\oplus su(2)$ which acts on the vector space $V_1\otimes V_2$, with action $(A,B)(v_1\otimes v_2)=(Av_1)\otimes(B v_2)$ (where $(A,B)\in su(2)\oplus su(2)$ and their actions on $V_i$ are determined by the spin $n_i$ representation).  I think this is correct, I just got very confused with the contrast between addition of angular momentum: in this case the vector space is still the tensor product, but the group action is different.


Correct plural usage for "hundreds" and "thousands"

I'm having problems with hundred and thousand.   If someone asks you, How many trees are in this forest? Would you answer seven thousand or seven thousands, because thousands are countable?  I know that you usually say seven thousand, but I also know that thousands are countable, so wouldn't that make it seven thousands?  And when you are talking about multiple countable nouns, you would make it plural, but the plural isn't thousand, it's thousands, so it couldn't be that thousand is the plural.  Why isn't it a few thousands? Is it because of an exception in English? Any help would be appreciated.


NullPointerException on setVisibility function in FrameLayout

I have developed android project and published to a google playstore. In this app, for tab use, at one activity, calling frameLayout.setVisibility(View.INVISIBLE) for showing other layouts. It is working perfectly on my android devices.  But when i check crashlytics, i can see applications crashed on that function.  I tried many google searches but i did not found the solution and did not fix yet.  Please help me on this issue.


Attempt to invoke virtual method Spinner.setAdapter(SpinnerAdapter) on a null object reference

FirstI'm trying to display the spinner into a dialog, I'm calling the data from database into ArrayList via getData object and everything is working fine but in the last step I got the above error when I tried to assign the adapter to the spinner and here is my code :      public class ViewDialogCities {     public void showDialog(int layoutID , Activity activity){          final Dialog dialog = new Dialog(activity);         dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);         dialog.setCancelable(false);         dialog.setContentView(layoutID);         Button OkButton =  dialog.findViewById(R.id.btn_dialog_ddl_ok);         Button CloseDialogButton =  dialog.findViewById(R.id.btn_dialog_ddl_cancel);         Spinner spn_ddl_dialog_list = findViewById(R.id.spn_ddl_dialog_list);           //Define data object         final GetData getData = new GetData();         ArrayList<String> getListOf;           //Retrieve data from data object and store it an ArrayList         getListOf = getData.getListOf("R");          //ArrayList to ArrayAdapter         ArrayAdapter<String> arrayAdapter = new ArrayAdapter                 ( HomeActivity.this, android.R.layout.simple_spinner_dropdown_item, getListOf);          arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);          // Assign ArrayAdapter to spinner         spn_ddl_dialog_list.setAdapter(arrayAdapter);          CloseDialogButton.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 dialog.dismiss();             }         });          OkButton.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {              }         });          dialog.show();     } }


Apostrophe to indicate the plural of a mathematical object

I have a question on the use of apostrophe to indicate the plural of a mathematical object.   Consider the sentence: "There are many values of X such that the statement is true".  In math, often we re-write this sentence as "There are many X's such that the statement is true".   Now, my question is: which one is correct (or preferred) between   "There are many X's such that the statement is true"  and  "There are many Xs such that the statement is true"   In case they are both wrong, please explain.


Do answers left on questions that subsequently get deleted impact the Answer Ban criteria for those users?

According to  on MSO there is an algorithm in place that is used to trigger whether a Question or Answer ban is automatically applied to a user.  However, if an answer is left to a question and that question is subsequently closed and deleted, this means all the answers are also deleted. Do these collateral damage deleted answers count towards the Answer Ban criteria?   These answers could well be good and well researched answers (albeit against poor questions) left in good-faith.  Yes, one could argue that people shouldn't be posting answers to bad questions in the first place, and that it's then their own fault if they end up being banned from answering because of it, but SE is full of people who just want to help out even when questions are poor, so should these people be punished in the same ways as people who just leave "lol, great post! Check out my free-coupon website" answers?


In MCU, how many characters have wielded more than one Infinity Stones?

Which characters have wielded atleast two infinity stones simultaneously in the MCU? Here is a list of all characters who have wielded the infinity stones (atleast one):  Loki wielded the tesseract (space stone) and a sceptor (mind stone) given by Thanos Red Skull/Hydra wielded the tesseract (space stone), Loki's sceptor (mind stone) (in a way, through machines) Ronan wielded the power stone Guardians of the Galaxy (mostly Peter Quill) wielded the power stone Vision wielded the mind stone Thanos, Hulk and Ironman wielded all six infinity stones Dr. Strange wielded the time stone Odin and Hella may or may not have wielded some stones, we are not sure...  (Please add other characters if I missed them) Considering (1) and (2) above, there are characters who have wielded more than one infinity stones at a time. Then why did the Ebony Maw say to Thanos the following while presenting the space stone:  No other being has ever had the might, nay the nobility, to wield not one, but two Infinity Stones  Since, Thanos gave the sceptor to Loki, surely Ebony Maw would know it, right? Or was he merely being a sycophant?


Image is fuzzy or noisy when rendered in cycles

When I rendered this image it became really fuzzy and pixelated. I have tried to fix this but it doesn't seem to be working.


Why is it "how come" and not "why come"?

When someone asks "How come?", the person answering actually answers the question "why?". "Why?" and "How?" are very different questions. I was wondering how "how come?" came to be an alternative way of asking "why?". Perhaps "how come?" is short form for something else?  I'm trying to understand the reason the word "how" came to be used in the phrase "how come". Why not use "what come", "who come", "when come" or "why come"?


Is there something similar to or compatible with LaTeX that supports more of a concept of external stylesheets?

I'm new to LaTeX and TeX in general. So far I'm really liking the possibilities it offers for making my documents functional, such as being able to use references to show the page number of another section of my content, or being able to automatically .  I also agree with LaTeX's core principle that writers shouldn't be responsible for formatting. My day job is in web development, and separation of styling and content is a major practice there. (CSS vs HTML)  Unfortunately, from what I've read so far it seems that LaTeX's real principle is that nobody should be responsible for formatting, and that you should just accept whatever formatting LaTeX gives you. In other words, LaTeX's .tex files appear to be the equivalent of HTML, but I can't find the equivalent of CSS.  I realise you can use .sty files to alter formatting, but these seem clunky and verbose, as well as not very flexible. Looking at the answers to  it seems the general opinion is that LaTeX doesn't do this well.  For example, if I want to make all my headings in a web page blue I can just do h1 { color: blue; }, but in LaTeX it looks like I have to completely overwrite the builtin command for a heading, duplicating all the existing functionality just to change one property.  I've considered using HTML and CSS as I'm used to them, but they don't handle pages well at all. (I'm not sure if it's even possible to do something basic like display the page number that a reference points to)  So is there a variant of LaTeX that supports a more powerful styling system? (Maybe there's some unholy version of LaTeX that supports CSS stylesheets) Or is there some other typesetting system that would have the page-aware features that LaTeX does. Maybe there's even a rendering engine for HTML+CSS that allows for this? Or maybe I'm misunderstanding something fundamental.  Sorry for the noob question, I've tried doing research but I think I'm approaching this all wrong as nothing I've read has answered my questions.


I have been given a problem as part of a practice set for a problem solving class. Here, I am asked to prove the following equality (for positive integers $m$ and $n$):  $\sum_{k=0}^{n}(-1)^k\binom{n}{k}\frac{1}{k+m+1}=\sum_{k=0}^{m}(-1)^k\binom{m}{k}\frac{1}{k+n+1}$  I have tried to form a counting argument,though that doesn't seem to be working too well. The theme of these problems is that they can be re-written as simpler problems, although I am just not sure how to do that here.   Some other things I tried include rewriting each sum as the difference of two other sums (ie putting the positive elements into one sum and the negatives into another) but that doesn't seem to simplify it at all...  Any help is much appreciated


How I get my command prompt to show just the name of the folder I'm in (not the whole path))

In a command prompt window (terminal), how can I get my prompt to be just the current folder?  e.g.  prompt $p $g   gives:  C:\Users\Robin >   But I want it to just show:  Robin >    UPDATE: As @Caius Jard said in the comments, the question identified doesn't duplicate this, as I don't want to simply remove the path, I want to have the current folder name included in the prompt.  e.g.   Program Files >   or   Users >   Hope that clarifies


I realized that I only had one nameserver configured for an EC2 web server I set up last year, as the other elastic IP didn't get associated. Everything seems to work though? Is it necessary to have a working second nameserver for an EC2 web server?


What "User was removed" means if I have no posts?

Most of us have seen on the profile page a loss of reputation citing as a reason "User was removed". This reason comes with the useful link:  which explains (emphasis mine):     This message means that a user who voted for one of your posts had their account deleted (either by request or due to violating the network's terms of service). As a result, all of their votes were removed, and the reputation you gained or lost from them was undone. The resultant reputation change could be any amount; it could even be a reputation gain if enough of the removed votes were downvotes. All the reputation changes from a single user's deletion are rolled into a single event in the reputation page labelled "User was removed".      This removal occurs whenever a user is deleted, unless that user had a very high reputation score. Because high-reputation users have usually cast a great many votes, removing all of them could be that much more disruptive to other users. In such cases, the staff use a special deletion that preserves the votes, resulting in no reputation change for those who had been voted on by that user.   However, I have got recently such a message on one of beta sites, where I have no posts. Here is  on that site. As you can see, I have only got points from association bonus,  and the last event in my reputation history is the reputation loss with the message 'User was removed'. (Notice that the post, where I made suggested edit, was not deleted. And the users who approved the posts are Community♦ and one another user, who did not delete their account.)  You can also see from  on that particular site that I have posted no questions/answers there so far. Which means there are no votes on my posts which could have been removed.     Why this did happen? How can I lose reputation points in this way if I have never made a post on that site?   I am not sure if this is a . (Feel free to remove the tag if it does not fit the question.) (EDIT: The answer and the comments posted so far indicate, that it is not a bug, so I have removed the tag from the question.) But if there is some reason why reputation posts can be lost even without having some posts and actual votes on the posts, then the description of "User was removed" seems to be a bit imprecise. (Of course, if it is a very rare edge case, it is probably not that important to have it included in the explanation.)    Just a short disclaimer: I do not care that much for the 2 points I lost. (Obviously, it would be very silly to make a fuss just for 2 points, and even more on a site which I do not frequent that much.) But if this could be indication of some hidden bug, it might be interesting to know more about this.    I have also noticed two related questions       In both cases in some answers or in comments as a possible explanation was given that probably a post, where a suggested edit was made, has been deleted. As you can see from the links I, this is not the case here.


Is it required to qualify a dependent name with typename if it is used as a template argument?

template<class mapT, class K, class V> void f(mapT& m, const K& k, const V& v) {     pair<mapT::iterator, bool> p = m.insert(make_pair(k, v)); }   MSVC accepts this code with no errors or warnings. What does the standard have to say about this? Are we allowed to (optional), not allowed to (forbidden), or required to (mandatory) qualify T::iterator with typename in the example above? I am particularly interested in C++03 rules although if anything has changed for 11 it would be nice to know. Thank you.


How do I install drivers for the Atheros AR8161 Ethernet controller?

I have installed Ubuntu 12.04-64 bit on my Lenovo IdeaPad laptop, and the wired Ethernet (LAN) connection doesn't work.  Running the lspci -vv | grep Atheros command from the terminal shows me I have the AR8161 Gigabit Ethernet controller:  02:00.0 Ethernet controller: Atheros Communications Inc. AR8161 Gigabit Ethernet (rev 08)   This looks like a new product whose drivers are not built into Ubuntu.  How do I install drivers to get the AR8161 working?


Why couldn't I install Skype before running `sudo apt update`?

I tried to install Skype on my PC, but it did not get installed. My friend ran the sudo apt update command. After the command had run he installed Skype. Then the installation ran easily.  So my question is, why wouldn't the installation run before running the command sudo apt update?


Type casting between derived class and base class

If I have a base class that I declared it as a child class, and then added to a vector consisting of the base class, is there a way to cast that base class back to a child class, since I know that the "base" is in fact the child? For example:  class Libitem{     //...... };  class Book : public Libitem{     //...... }  int main{     vector<Libitem> lib;     Libitem book = Book();     lib.push_back(book);     Book b = static_cast<Book>(lib.at(0)); //this is wrong. Is there a way to do this correctly? }   Am I doing my cast wrong or is their something that I'm misunderstanding?


Sum and Multiplication of Two Normal Distributions

I'm not sure about how to go about this question. How do we deal with the variances when the two normal variables are summed?


is it possible to rsync to another server using crontab?

Hi there is a bunch of videos and resources on how to rsync locally rsync /home/user1 /home/user2/backup, but i haven't found any tutorials on rsync crontab to another server  pretty much, i use crontab -e and i have a script i run from rsynch.sh  #!/bin/bash rsync -xza /home/willchap  willchap@server02:/home/willchap/backup   it will work fine without crontab, the problem is, i am guessing crontab fails because it is asking for a password  what are my options here?


An unhandled exception of type 'System.StackOverflowException' occurred and few different issues with toString first

I have been working on this all day and can't figure out why I can't pull this to print of the main class, keeps throwing an error     An unhandled exception of type 'System.StackOverflowException' occurred   I've tried a few things now and nothing. It works to pull my list from on another class, but I can replicate it. Sorry about code been adjusting a lot  using System; using System.Collections.Generic;  namespace MpaintV2.Customer {     public class Trade     {         public String TradeName { get; set; }         public String TradeAddress { get; set; }         public String TradePhone { get; set; }         public Double PaintCoverage { get; set; }         public String TradeNames { get; set; }          public string RecCal         {             get { return RecCal; }             set { RecCal = RecCal; }         }          public string DataTrade         {             get             {                 List<string> FileData = Utilities.Helper.get_file_data();                  for (int counter = 0; counter < FileData.Count; counter++)                 {                        String[] SplitRecord = FileData[counter].Split(',');                      if (SplitRecord[0].Equals("Trade"))                     {                         TradeName = SplitRecord[1];                         TradeAddress = SplitRecord[2];                         TradePhone = SplitRecord[3];                         PaintCoverage = (double.Parse(SplitRecord[4]) / 10.00);                         // Console.WriteLine(" " + TradeName + " " + TradeAddress + " " + TradePhone + " " + PaintCoverage + "Paints");                         //List<String> TradeFiles = new List<string>();                         //TradeNames = String.Join(TradeName, TradeFiles[500]);                     }                 }                  //TradeFiles = TradeName.Insert.TradeFiles;                 RecCal = TradeNames + TradeAddress + TradePhone + PaintCoverage + "otherthings";                 return RecCal;             }         }          public override string ToString()         {             return base.ToString();         }     } }


Credit card details stolen every 1-2 years. What am I doing wrong?

Background I just had my credit card canceled because of fraud.  This is actually a perfectly normal occurrence for me, which is the impetus behind this question.  The card in question was only about 1.5 years old, because that is how long it has been since my previous card details were stolen. Over the past decade I would say that I have had my credit card canceled for fraud on average once every 2 years.  I think there was once I made it to 3 years, but also at least once where I only made it a year before it happened again. To be clear it isn't being physically stolen and I've never once lost my card.  I obviously have no idea how it happens every time (although I'm certainly aware that there are plenty of ways for your card data to be stolen without you knowing).  I generally consider myself someone who practices reasonable credit card security.  I don't use my card at gas pumps (gas pump skimmers were common in my area for a while), I only use it with major e-commerce vendors online, and I usually use cash at restaurants rather than handing someone my card. Most people seem surprised that my details get stolen so often, which makes me wonder if I'm doing something wrong even still.  However, I don't actually know if that is the case.  Fortunately it isn't more than a nuisance for me when it happens.  I've never had to pay for any of the fraud and the bank always sends me a new card with a minimal of hassle.  It just "costs" me the inconvenience of being card-less for a week or two and then having to update my credit card details everywhere.  Still if there were additional steps I could take to minimize the chance of fraud I would take them to try to stop this from happening so often.  So, I realize this is a bit broad, but: The Question  Is having my card details stolen every 2 years a sign that I am unlucky, doing something wrong, or is it perfectly normal? Are there any other steps I can take to minimize the chances of this happening in another 1-2 years?  A Second card So far I've had lots of comments about having a second card.  That's not a crazy idea, and hasn't really occurred to me.  It can certainly help when I'm down a card, although it also has its own disadvantages (one more thing to check every week, one more place to make payments, etc...).  Still, while strategies to minimize the inconvenience when my card gets stolen are helpful, I'd rather come up with ways to minimize the chances of my card getting stolen in the first place. Fraud Example As an example of the actual fraud, I found out my card was canceled when it was declined at a grocery store.  I immediately went home and checked my transactions online.  I saw a number of smaller transactions that were definitely fraud.  Two were $0.30 transactions from a retailer who's name was literally a random string ~20 characters long and based out of Indiana (I'm in Florida).  Then there were two ~$10 charges claiming to be from a magazine which I had never heard of.  Those transactions were allowed by my card (although the transactions will likely be canceled before any money exchanges hands, and I certainly won't have to pay for them). When I called Visa they asked about further charges that I didn't see on my bank statement because they had been declined.  That included my attempt to get groceries, ~$500 at a travel center in Zurich, and a large number of smaller transactions that I can't remember.  All of this makes me suspect that regardless of how my credit card was obtained, it found its way into the larger credit card fraud world where criminals try to turn stolen cards into actual cash.  The small transactions followed by larger ones matches my own expectations in this area from my personal and professional experience - small transactions are first performed to verify that the credit card details are still valid while trying to stay under the radar, and then larger transactions are made for products that can be converted to cash (unfortunately I have no idea what was being "purchased" at the travel center in Zurich).


Are there any non-contraction you-plural words in English besides 'yourselves'?

I can only think of yourselves as a single word that is related to (only) you-plural and isn't a verb. The other one I can think of is y'all but that's more of a contraction.


How do I make my layers appear in a certain orientation?

Okay, so I am working on this little pet project just for fun. It's a wallpaper for my friend with his gamertag. My problem, is that I can't seem to find the right node orientation/ settings to get his tag to appear in FRONT of the shockwave. Everything I try won't help, and it still looks like it's either between the red and purple, or behind both. Anyone got any ideas?


Can we use 'be' after 'wish' to express a wish?

Of late, I came across a writing in which the writer has written, 'I wish you be a good human.' Is this correct to say I wish you be......? Your take on this.


If you have dis/advantage on a roll, do you have dis/advantage on a reroll?

This might be a duplicate but I can't find it.  To be clear this has nothing to do with Halfling Luck trait. Or similar abilities that allow the reroll of a die that rolls a natural 1. (I was apparently incorrect though.)  This has to do with a situation such as the 's Fanatical Focus feature (Xanathar's Guide to Everything, p. 11), which lets you reroll a save that you fail:     Starting at 6th level, the divine power that fuels your rage can protect you. If you fail a saving throw while you’re raging, you can reroll it, and you must use the new roll. You can use this ability only once per rage.   Situation: Barbarian fails his save and is afflicted with . Now he has disadvantage on Constitution checks and saves. He is targeted with  and fails his save. Using Fanatical Focus, he chooses to reroll that save. He would obviously have disadvantage again since the curse is ongoing. I think we could all agree to that.  However, what if the disadvantage or advantage was only imposed for that effect? Such as a Sorcerer using the Heightened Spell  option:     When you cast a spell that forces a creature to make a saving throw to   resist its effects, you can spend 3 sorcery points to give one target   of the spell disadvantage on its first saving throw made against the   spell.   The ability says you "reroll that save", therefore I argue that you would have disadvantage again as it would still be the first saving throw against the spell albeit a meta-game solutioning of that resolution.  I was unable to find anything on Sageadvice.eu although it is getting harder to sift that data. And I did not find anything in the errata or the .  Is there anything to support this ruling in the rules that I missed?  This seems intuitive and intended however I see nothing that alludes to it.


A girl with magical power in a different world

I read a book quite a while back (probably quite a few years ago) that I downloaded (probably for free, but maybe not) on iBooks. I do not have iTunes anymore so I can't find it from there.   It was a fantasy book about a girl with magical ability. It was set in a different world to ours. Kind of medieval-esque? It starts with her in this keep, and she works there since her mother died. There are creepy guys there but she used her magic to hurt one and now they stay away. Then this man comes along, realises she can do magic, and takes her away and trains her. There is a big plot about saving the world I think. And there's a warm hot country where there is a man called something like Soluman.   That's all I can remember. If anyone knows or thinks they know what this is, could you please tell me? I know this is very vague, but it's all I can pin down. I'm pretty sure this was part of a trilogy or series of books. And I think it had a female author.


Why are existing but unused tags unusable?

The annotation above is misleading. This question is about the listing of unused tags, leading the user to conclude that they are available. The bug is that they behave like new tags, but are also still listed.  So I've come upon a situation where there were more tags than one with no use associated with them. When I tried to use one of them, I got an error when I tried to submit my question:     Creating the new tag '[tag name]' requires at least 500 reputation. Try something from the existing tags list instead.   Funny thing was, it was already listed. Is this a bug? Does it exist only on certain sites or across the network?  Edit: I first encountered this issue several weeks ago, but apparently the tag I referenced has already been deleted.


If $p~ \mid~ m^p + n^p$, prove $p~ \mid~ \frac{m^p + n^p}{m+n}$.

If $p \mid m^p + n^p$, and $p$ is a prime greater than $2$, prove $$p \mid \frac{m^p + n^p}{m+n}.$$  No clue how to start. Clearly $p \mid m + n$, but then what. I feel very less information is given. Yet primes are full of surprises.  Thanks in advance.


In QGIS 1.8 I used the openstreetmap plugin to request data from the server, or open a .osm XML file, which produced 3 layers (polygons, polylines and points) in QGIS.  This was great (give or take the 64bit bug which highly affects the freshly mapped area I work on), but how do I do that in QGIS 2.x?   I can't find any updated documentation about it.  In the vector menu, I've tried importing from osm servers, I get a .osm file, but then I'm stuck. There's a menu option for loading an XML file, but it produces a spatialite db, which apparently only has non-geometry tables when I try to add it as a spatialite layer. If I open the attribute table, I can see node ids, ways and so on, but I can't figure out how to actually make use of them.  I've also tried adding a vector layer from a .osm XML file. I get a gpsbabel window that shows nothing, then finally an invalid data source message in QGIS.


Difference Between Radiometric calibration and radiometric correction

I am new in remote sensing field. I sometimes got confused when I read about image pre-processing. Can someone please elaborate to me the difference and some example methods to do radiometric correction and radiometric calibration ?  Is converting DN values to Top Of Atmospheric (TOA) reflectance values from 2 sets of images (e.g Landsat 7) from different time counted as correcting or calibrating ? Are DOS (Dark Object Subtraction) and Sun-angle correction parts of radiometric correction ?


Why can't Ubuntu be installed on BIOS when UEFI is existing (Windows 7 is already installed on BIOS)

Windows 7 is installed on the first 2 partitions (100MB & 250GB) (in BIOS Mode).   Now I want to install Ubuntu 18.04 on the next partition but it doesn't find Windows 7. The installer finds the partitions. If I install it on the empty partition, after finishing I can only boot Ubuntu. If I try it with Ubuntu 16.04 I get a message saying that Windows 7 is installed in BIOS mode, but it wants to install in UEFI, and that then I won't be able to use Windows 7 any more. and so it is.   But why can't Ubuntu also be installed in BIOS mode?


Are there any speedy alternatives to the EM algorithm for learning models with latent variables (especially pLSA)? I'm okay with sacrificing precision in favor of speed.


Prove $\sin\alpha \cos\alpha + \sin\beta \cos\beta + \sin\gamma \cos\gamma = 2\sin\alpha \sin\beta \sin\gamma$, where $\alpha + \beta + \gamma = \pi$

This identity stems from:$$\tan\alpha + \tan\beta + \tan\gamma = \tan\alpha \tan\beta \tan\gamma$$ (for $\alpha + \beta + \gamma = \pi$) which can easily be proven using the $\tan(\alpha + \beta)$ identity.  However, I have been unable to prove $$\sin\alpha \cos\alpha + \sin\beta \cos\beta + \sin\gamma \cos\gamma = 2\sin\alpha \sin\beta \sin\gamma,$$ where $\alpha + \beta + \gamma = \pi$.  EDIT: I proved it. From $\alpha + \beta + \gamma = \pi$ we have$\alpha = \pi - (\beta + \gamma)$ This implies  $$ \sin\alpha = \sin(\beta +\gamma) \quad \text{and }\quad \cos\alpha = -\cos(\beta +\gamma).$$ Then, we have  $$\begin{align} \sin\alpha \cos\alpha &=-\sin(\beta +\gamma)\cos(\beta + \gamma)\\  &= -(\sin\beta \cos\gamma + \sin\gamma \cos\beta)(\cos\beta \cos\gamma - \sin\beta \sin\gamma)\\   &= -(\sin\beta \cos\beta \cos^2\gamma \ - \sin\gamma \cos\gamma \sin^2\beta + \sin\gamma \cos\gamma \cos^2\beta - \sin\beta \cos\beta \sin^2\gamma)\\   &= -[\sin\beta \cos\beta \ (\cos^2\gamma - \sin^2\gamma) + \sin\gamma \cos\gamma \ (\cos^2\beta - \sin^2\beta)]\\   &= \sin\beta \cos\beta \ (\sin^2\gamma - \cos^2\gamma) + \sin\gamma \cos\gamma \ (\sin^2\beta\ - \cos^2\beta ) \end{align}$$ Substituting this in $\sin\alpha \cos\alpha + \sin\beta \cos\beta + \sin\gamma \cos\gamma$ we get  $$\begin{align} \sin\beta \cos\beta &(\sin^2\gamma - \cos^2\gamma) + \sin\beta \ cos\beta + \sin\gamma \cos\gamma \ (\sin^2\beta\ - cos^2\beta) + \sin\gamma \cos\gamma \\  &= \sin\beta \cos\beta \ (\sin^2\gamma +1 - \cos^2\gamma) + \sin\gamma \cos\gamma \ (\sin^2\beta +1 - \cos^2\beta)\\   &= \sin\beta \cos\beta \ (\sin^2\gamma + \sin^2\gamma) + \sin\gamma \cos\gamma \ (\sin^2\beta +\sin^2\beta)\\   &= \sin\beta \cos\beta \ (2\sin^2\gamma) + \sin\gamma \cos\gamma \ (2\sin^2\beta)\\   &= 2\sin\beta \sin\gamma \ (\sin\gamma \cos\beta + \sin\beta \cos\gamma)\\   &= 2\sin\beta \sin\gamma \sin(\beta + \gamma)\\   &= 2\sin\beta \sin\gamma \sin\alpha\\  &= 2\sin\alpha \sin\beta \sin\gamma. \end{align}$$


how to scale in inches instead of percentage

When I try to scale down a circle by entering a number in inches, blender takes that number as a percentage and scales accordingly. How do I change that to equal inches?


Host a website with a domain so others can access it?

I'm currently hosting WordPress on localhost on WAMP (Windows 10). The site works fine, but I don't know how to make it so that I set a .com domain I already own and leave my computer on so anyone in the world can access it. Sorry if this was asked before and is a basic question; I didn't see it already asked from the search bar. Also, my IP address is dynamic, so I don't know how that'd work either.


Use of a semicolon before and comma after "however"

Several years ago, a previous boss told me to use a semicolon and comma with the word "however".  I've always questioned this and would like to know if the following random sentences are using the correct method.        Our plane was delayed overnight; however, the airlines reimbursed us for lodging.   It looks as though he's upset; however, she told me he always has that look on his face.   I want to find him a nice gift; however, I am a broke until payday.      Normally I would use a less "wordy" sentence in casual writing, but hopefully the example will suffice.  For example, on number 3 I would usually type:      I want to get him a nice gift, but I'm broke until payday.


prove triangular inequality for $ d(x,y)= \frac{||x-y||}{1+||x-y||}$

prove triangular inequality for $$ d(x,y)= \frac{||x-y||}{1+||x-y||}$$ that is $d(x,y) \leq d(x,z)+d(z,y)$ ofcourse ||.|| is a norm and has properties of norms    this usually works    $$ \begin{aligned}                 d(x,y) = &\frac{||x-z+z-y||}{1+||x-y||}                          \\ & \leq \frac{||x-z|| +|| z-y||}{1+||x-y||}  = \frac{||x-z||}{1+||x-y||} +\frac{||z-y||}{1+|x-y|} \\& \vdots \\ & =\frac{||x-z||}{1+||x-z||} +\frac{||z-y||}{1+|z-y|}=d(x,z)+d(z,y)       \end{aligned}$$ therefore $d(x,y) \leq d(x,z)+d(z,y)$  but this dosent work. the next thing to do for mylself is try to go the other way start with right side of $\leq $ and get the other side. thiniking need to use schartz inequality. if this was on a quiz or test it would be taking too much time for me  second way attempt (I think it is closer) $$ \begin{aligned}    d(x,z)+d(z,y) &= \frac{||x-z ||}{1+|x-z||}+\frac{||z-y ||}{1+||z-y||}                 \\ & = \frac{||x-z ||}{1+|x-z||} * \frac{1+||z-y||}{1+||z-y||}           +\frac{||z-y ||}{1+||z-y||} * \frac{1+|x-z||}{1+|x-z||} \\&=\frac{||x-z||+||x-z|||z-y||}{1+||z-y||+||x-z||+||x-z|||z-y||}     +\frac{||z-y||+||z-y||||x-z||}{1+||z-y||+||x-z||+||x-z|||z-y||} \\&=\frac{||x-z||+||x-z|||z-y||+_||z-y||+||z-y||||x-z||}{1+||z-y||+||x-z||+||x-z|||z-y||}   \\&= \frac{2||x-z|| ||z-x||}{1+||z-y|| ||x-z||} \\& \vdots (missing steps, )  \geq  \frac{||x-y|||}{1+||x-y||}=d(x,y) \end{aligned}$$  stuck, im going to be stubborn and still try to finish this proof later hopefully and think is done diff from the "duplicate"excersises (but I just glanced at them). after some thinking, The duplicate does answer the question way elegantly and I did a stupid mistake on my second attempt on second to last line.


Annotating images on QGIS or using widgets?

I've georeferenced an old map on qgis and layered it on top of OSM, I want to do a class project and for it I would like to pinpoint certain areas on the map of which I have old photographs. I would like to know if it's possible to pinpoint the locations and attach photographs, so you can see photos of what that place used to look like, as well as write textual information. I know that you can do text annotations, but how about images?   I would like it to be something similar to like when you get locations pinpointed on google maps and when you press on the pinpoint you get the photo and information.


I have problem about setting new project. I just installed wamp 2.2E. I am using windows XP. In folder /www I created folder /example. In WINDOWS/system32/drivers/etc/hosts I added   127.0.0.1       dev.example.com   and in G:\wamp\bin\apache\apache2.2.22\conf\extra\httpd-vhosts.conf added at the end  NameVirtualHost dev.example.com:80 <VirtualHost dev.example.com:80>    DocumentRoot "G:/wamp/www/example"    ServerName dev.example.com    ServerAlias dev.example.com     <Directory "G:/wamp/www/example">       Options Indexes FollowSymLinks ExecCGI Includes       AllowOverride All       Order allow,deny       Allow from All    </Directory> </VirtualHost>   The problem is when I go to dev.example.com/index.php I still get content from www/index.php instead of www/example/index.php. Did I miss anything?


What is difference between Cryptographic Transformation, Encryption and Hash?

I read in a book that: let $f(K,R)$ is cryptographic transformation of $R$ using $K$, $K\{R\}$ means $R$ is encrypted using $K$ and $h\{R\}$ is the hash of $R$ and then the example follows.  I want to know what is difference between cryptographic transformation of $R$ and encryption of $R$ using the same key? Aren't they same thing?


My script:  date echo -e "${YELLOW}Network check${NC}\n\n"  while read hostname do  ping -c 1 "$hostname" > /dev/null 2>&1 &&  echo -e "Network $hostname : ${GREEN}Online${NC}" || echo -e "${GRAY}Network $hostname${NC} : ${RED}Offline${NC}"  done < list.txt         sleep 30 clear done   Is outputting info like this:    Network 10.x.xx.xxx : Online    Network 10.x.xx.xxx : Offline    Network 10.x.xx.xxx : Offline    Network 10.x.xx.xxx : Offline    Network 10.x.xx.x : Online    Network 139.xxx.x.x : Online    Network 208.xx.xxx.xxx : Online    Network 193.xxx.xxx.x : Online   which I'd like to clean up to get something like this:    Network 10.x.xx.xxx       : Online   Network 10.x.xx.xxx       : Offline    Network 10.x.xx.xxx       : Offline     Network 10.x.xx.x         : Online     Network 139.xxx.x.x       : Online   Network 208.xx.xxx.xxx    : Online     Network 193.xxx.xxx.x     : Online   Network 193.xxx.xxx.xxx   : Offline


I got this question in interview, it seems simple one but I want to confirm my understanding about its functioning.  f (char *p, char *q, int n) {     int i1 = n >> 2;     int i2 = n & 3;      switch (i2)      {         do {             *q++ = *p++;             case 3:  *q++ = *p++;             case 2:  *q++ = *p++;             case 1:  *q++ = *p++;             case 0:  ;         } while (i1--);     } }   I was asked below questions in interview:    What this function does? Why would somebody write such convoluted code? Is there any way to write it differently (simpler, faster)?   Answers given:   This function copies the number of elements from the memory where *P is pointing to the memory where *q is pointing. if you will write it with for loop as below (writing only loop)  for(i=0;i<n;i++)    *q++ = *p++;   then the compiler taking more MIPS/time in condition checking. In this it will first subtract i from n and then checks is I non zero ? In the given code while loop maintain condition only 1 condition if i1 is non-zero ? So in while loop there is less condition checking. We can write as:  f (char *p, char *q, int n) {   for(i=n;i--;)     *q++ = *p++; }   It seems simple and faster to me.   Please give me your opinion.


Working with a Routhian for a specific system

I asked a more general  earlier about the Routhian, but I'm still having trouble working with it. Here's my specific case. Given the following Lagrangian:  $$L=(1/2)m(\dot{r}^{2}+r^{2}\dot{\phi}^{2}sin^{2}\theta_{0})-mgrcos(\theta_{0}),$$  I obtained the corresponding Routhian:  $$R=(1/2)p_{\phi}\dot{\phi}-(1/2)m\dot{r}^{2}+mgrcos\theta_{0}.$$  I'm being asked to do the following: obtain the Hamilton equation of motion for $p_{\phi}$, show that it's constant in time and find its initial value, obtain the Lagrange equation of motion for $r$ from the Routhian, and obtain the Hamiltonian  When I try to do the first part (obtain the Hamilton e.o.m.) I get $∂R/∂p_{\phi}=(1/2)\dot{\phi}$ which doesn't show that it's constant in time or that angular momentum is conserved, which I think is what we're trying to show here. What am I doing wrong? Also, how can I obtain the Lagrange e.o.m. for $r$ using the Routhian? Do I just take  $$\frac{d}{dt}\frac{∂R}{∂\dot{r}}-\frac{∂R}{∂r}=0,$$  since $r$ appears in the Routhian and plug in $r=r_{0}$ to find the initial value? Similarly, how do I go about obtaining the Hamiltonian from the Routhian?


in a host named site collection using the team template, I would like to hide the Site Contents link, but cannot find any way to do it. does anyone know how?  deleting it from quick launch editor does not work. any solution relying on _layouts/15/ChangeSiteMasterPage.aspx does not work - the page does not exist or is not reachable. being able to edit site master page settings would be very useful as I could then add alternate css.  removing the link entirely is an acceptable option, although a better one would be to hide it only for non-admin users.  sharepoint 2013 sp1 enterprise farm, sql server 2012, windows server 2012 r2


I'm trying to install tor on my Kali Linux 2016.1 (kali-rolling). When I type apt-get install tor in Terminal, this error appears:  Reading package lists... Done Building dependency tree        Reading state information... Done Package tor is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'tor' has no installation candidate   How can I fix this and install tor?  UPD:  I tried this:  - I added deb http://deb.torproject.org/torproject.org wheezy main to sources file, but it didn't help at all, so I deleted this string and now it's in a default condition


How can I get mv (or the * wildcard) to move hidden files?

I am migrating my home directory from an old system to a new one, and the tarball I made contains everything, including hidden files like .bashrc. However, when I move the contents of the unpacked tarball (which are in /tmp) to my new home directory, the hidden files do not copy (mv /tmp/home/rcook/* /home/rcook/). How can I get mv to move them?  Actually, I think the problem is not with mv, but with bash's globbing. If I do this:  mkdir a mkdir b touch a/.foo touch a/bar mv a/* b/ ls -a a/ b/   I see this:  a/: .  ..  .foo  b/: .  ..  bar   a/.foo did not move. So how can I get the * wildcard to find hidden files?  Yes, I suppose I could decompress the tarball directly into my home directory, but the tarball decompresses into home/rcook/..., and I want to be sure I overwrite the new .bashrc, etc. with the old, customized versions, and knowing how to find and move hidden files is a worthwhile skill. Suggestions?    Some answers suggest doing something like mv src/.* dest/. However, I tried this on my test directories and got errors. Starting with:  rcook$ ls -a a/ b/ a/: .  ..  bar  .foo  b/: .  .. rcook$ mv a/.* b/ mv: cannot move 'a/.' to 'b/.': Device or resource busy mv: cannot remove 'a/..': Is a directory rcook$ ls -a a/ b/ a/: .  ..  bar  b/: .  ..  .foo   What am I doing wrong?


Had a CyberpowerPC c-series: AD3U1600W4G11-B ( 4 RAM ). My new Computer is also a cyberpowerPC GUA1400BST series: TED38G1600C11BK ( 8 RAM ). New PC is a dual channel.


Bibliography and headers with titleps and biblatex

I am using titleps to get custom headers, and biblatex for the bibliography. The headers look all right except when it comes to the bibliography, where a "REFERENCES" label appears in the header and footer. Here is a MWE:  \documentclass{article} \usepackage{lipsum} \usepackage{titleps} \newpagestyle{fancy}{  \headrule \sethead[\normalsize \thepage][][] {Author}{Document}{\normalsize \thepage} \setfoot[][][]{}{}{} } \usepackage{filecontents} \begin{filecontents}{\jobname.bib} @article{A2013, author = {Author, A}, title = {A nice paper}, journal = {Journal}, year = {2013}, volume = {1}, pages = {1--2}, } \end{filecontents}  \usepackage[style=numeric,backend=biber]{biblatex} \addbibresource{\jobname.bib}  \begin{document} \pagestyle{fancy}  \lipsum[1] \cite{A2013}    \clearpage  \printbibliography  \end{document}   And here is the output:   The left page is ok but not the right page. Where does the "REFERENCES" label come from?  Note that this does not happen if I use bibtex instead of biblatex for the bibliography, or fancyhdr instead of titleps to customize the headers. For instance, replacing lines 3-9 in the example with  \usepackage{fancyhdr} \pagestyle{fancy} \fancyhead{Document} \fancyhead[L]{Author} \fancyhead[R]{\normalsize \thepage} \fancyfoot{} \fancyfoot[C]{} \renewcommand{\headrulewidth}{0.5pt} \renewcommand{\footrulewidth}{0pt}   gives the expected output:   How can I obtain the same result with titleps and biblatex?


don't provide only vs don't only provide

I am stuck at this problem "We don't provide only wireless equipment"  or "We don't only  provide wireless equipment" In the above-mentioned sentences, which one is correct? Please help me.


Sorting a dictionary alphabetically regardless of capitalization

I have a dictionary that basically matches a number to a character, e.g.  foo = {'z':1, 'A':1, 'a':1, 'b':3}. The dictionary is currently completely randomized both numerically and alphabetically, however I do know how to sort is numerically, but I currently just want sort the characters alphabetically regardless of capitalization. So far I have tried using sortednames=sorted(foo.keys(), key=lambda x:x.lower()) but that returns a list of the sorted characters and now the matching numbers are gone. Does anyone know how to solve this?


Literature on Quantum Field Theory/Standard Model Physics?

I am looking for a self-contained book that explains the concepts of QFT in the most general way but that still explains the mathematical concepts which surprass the general level of physics undergraduate studies. Also, it should describe the full Standard Model of particle physics with method of QFT. Does anyone have some recomendations?


free up /boot .. can't install new software

I was trying to install Mixxx to see how well it would work with Calf/other JACK programs, but when it started installing it gave me an error saying out there wasn't any free space on /boot  looking at other's questions on askubuntu and the ubuntu forums, I guess I'm kind of confused, because I didn't see any that dealt with just software, not upgrades or kernel installations.  I did   uname -r 3.8.0-31 generic   and then  sudo dpkg --list 'linux-image*'   which gave back a few results, numbering from 3.8.0-19 through 3.8.0-31.46  Maybe the other posts were just older in general, but other posts were saying to get rid of kernels like 2.6 and 2.8, but not anything this recent. Is it okay to delete all the kernels that aren't the 3.8.0-31 generic one?


I just upgraded linux-firmware package and after that I used $ sudo update-initramfs -u -k all but I got some errors:  $ sudo update-initramfs -u -k all [sudo] password for piotrek:  update-initramfs: Generating /boot/initrd.img-4.4.0-34-generic Warning: No support for locale: en_US.utf8 update-initramfs: Generating /boot/initrd.img-4.4.0-31-generic Warning: No support for locale: en_US.utf8 update-initramfs: Generating /boot/initrd.img-4.4.0-13-generic WARNING: missing /lib/modules/4.4.0-13-generic Ensure all necessary drivers are built into the linux image! depmod: ERROR: could not open directory /lib/modules/4.4.0-13-generic: No such file or directory depmod: FATAL: could not search modules: No such file or directory Warning: No support for locale: en_US.utf8 depmod: WARNING: could not open /var/tmp/mkinitramfs_LJbkti/lib/modules/4.4.0-13-generic/modules.order: No such file or directory depmod: WARNING: could not open /var/tmp/mkinitramfs_LJbkti/lib/modules/4.4.0-13-generic/modules.builtin: No such file or directory   I'm sure I don't have kernel 4.4.0-13. I might have had it some time ago but removed it:   $ apt list --installed | grep linux-  WARNING: apt does not have a stable CLI interface. Use with caution in scripts.  linux-base/xenial,xenial,now 4.0ubuntu1 all [installed,automatic] linux-firmware/now 1.159 all [installed,local] linux-headers-4.4.0-31/xenial-updates,xenial-updates,xenial-security,xenial-security,now 4.4.0-31.50 all [installed] linux-headers-4.4.0-31-generic/xenial-updates,xenial-security,now 4.4.0-31.50 amd64 [installed] linux-headers-4.4.0-34/xenial-updates,xenial-updates,xenial-security,xenial-security,now 4.4.0-34.53 all [installed] linux-headers-4.4.0-34-generic/xenial-updates,xenial-security,now 4.4.0-34.53 amd64 [installed] linux-image-4.4.0-31-generic/xenial-updates,xenial-security,now 4.4.0-31.50 amd64 [installed] linux-image-4.4.0-34-generic/xenial-updates,xenial-security,now 4.4.0-34.53 amd64 [installed] linux-image-extra-4.4.0-31-generic/xenial-updates,xenial-security,now 4.4.0-31.50 amd64 [installed] linux-image-extra-4.4.0-34-generic/xenial-updates,xenial-security,now 4.4.0-34.53 amd64 [installed] linux-libc-dev/xenial-updates,xenial-security,now 4.4.0-34.53 amd64 [installed] linux-sound-base/xenial,xenial,now 1.0.25+dfsg-0ubuntu5 all [installed] syslinux-common/xenial,xenial,now 3:6.03+dfsg-11ubuntu1 all [installed] syslinux-legacy/xenial,now 2:3.63+dfsg-2ubuntu8 amd64 [installed]   How to fix those update-initramfs errors?


Model process for curved objects (Stool Legs)

I'm trying to wrap my head around this for a while now. It's a simple question for what I think will be a not so simple answer. How would you go about modeling one leg of this stool? I would like to do it without using sculpt mode because I can't get things quite clean enough.


How to have only 1 space between a word and a counter

I am using the following counter:  \newcounter{foo}   \newcommand\num{     \refstepcounter{foo}       \thefoo.}   Two (2) spaces are automatically inserted between the preceding word and the counter -- e.g., word \num shows up in the pdf file as word  1.  Is there a way to have just one space between a word and a counter?  If possible, I'd like to avoid writing word\num and would prefer to write it like word \num


Why is ip address listed as 172.18.0.150/24?

Why is IP Address listed with this notation 172.18.0.150/24? I mean the ip is 172.18.0.150 only why it haves /24?, and then whatever what subnet that is on should be someone else's worries, no?  3: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether f8:b1:56:ba:ae:ee brd ff:ff:ff:ff:ff:ff inet 172.18.0.150/24 brd 172.18.0.255 scope global eth0   If I want to reach 172.18.0.150 on some interface (ethX) on another computer I could add in the routing table of that computer:  ip route add 172.18.0.150/25 dev ethX or ip route add 172.18.0.150/24 dev ethX or ip route add 172.18.0.150/23 dev ethX or ip route add 172.18.0.150/8 dev ethX    right? So what does /24 really have to do with my address on my NIC? It seems it only has to do with routing, no? So why list it in ip addr?  Is 172.18.0.150/24 on the same "net" as 172.18.0.150/8 or are these two completely different IP addresses?


I have an acer aspire one netbook I installed Ubuntu studio because windows xp became unusable and deleted half of the files (I didnt they just disappeared) and now im trying to install windows 7 I have everything but my laptop is not letting me boot from my 64 gig PNY flashdrive it will just resume Ubuntu how do I format my hardrive deleting EVERYTHING?? I have tried commands and everything nothing is working


How are answers with the same vote score sorted?

When a new question is asked how are the answers sorted?  I just answered a question and there were two other answers.  All three answers have 0 votes and no edits.  Immediately after I answered my answer appeared first.  Now the order refreshed,  it appears they are sorted by reputation.


I am about to start a new research project, and want to ask/poll the community on what technology stacks they think I should use beyond ones that I would provide and explain.  Where can I ask my software engineering question, preferable on Stack exchange, as I like the portfolio and community?


According to  (my emphasis),     In statistics, the standard deviation ... is a measure that is used to quantify the amount of variation or dispersion of a set of data values. A standard deviation close to 0 indicates that the data points tend to be very close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the data points are spread out over a wider range of values.   The purpose of the standard deviation (SD), then, is to tell us how varied or uniform (SD → 0) the data is.  So, given a certain SD, how varied is the data? What does the size of the standard deviation mean?  Please explain the meaning of the SD by interpreting an SD = 1 (M = 0).  If you cannot interpret the size (quantity) of this SD, what other information would you need to be able to interpret it, and how would you interpret it, given that information? Please provide an example.  If, on the other hand, the quantity of the SD cannot be qualified in this manner, my argument is that it is essentially meaningless. If you disagree, please explain the meaning of the SD.       The following are earlier versions to give context to the answers. Unfortunately these didn't really convey what I wanted, and my attempt to ask it elsewhere was closed. (I don't need these versions answered now):  First revision:  What does the size of the standard deviation mean?  For example, if I want to study human body size and I find that adult human body size has a standard deviation of 2 cm, I would probably infer that adult human body size is very uniform, while a 2 cm standard deviation in the size of mice would mean that mice differ surprisingly much in body size.  Obviously the meaning of the standard deviation is its relation to the mean, and a standard deviation around a tenth of the mean is unremarkable (e.g. for IQ: SD = 0.15 * M).  But what is considered "small" and what is "large", when it comes to the relation between standard deviation and mean? Are there guidelines similar to the ones that Cohen gives for correlations (a correlation of 0.5 is large, 0.3 is moderate, and 0.1 is small)?    Original question:  We always calculate and report means and standard deviations. But what does the size of the variance actually mean?  For example, assume we are observing which seat people take in an empty room. If we observe that the majority of people sit close to the window with little variance, we can assume this to mean that people generally prefer siting near the window and getting a view or enough light is the main motivating factor in choosing a seat. If on the other hand we observe that while the largest proportion sit close to the window there is a large variance with other seats taken often also (e.g. many sit close to the door, others sit close to the water dispenser or the newspapers), we might assume that while many people prefer to sit close to the window, there seem to be more factors than light or view that influence choice of seating and differing preferences in different people.  At what values can we say that the behavior we have observed is very varied (different people like to sit in different places)? And when can we infer that behavior is mostly uniform (everyone likes to sit at the window) and the little variation our data shows is mostly a result of random effects or confounding variables (dirt on one chair, the sun having moved and more shade in the back, etc.)?  Are there guidelines for assessing the magnitude of variance in data, similar to Cohen's guidelines for interpreting effect size (a correlation of 0.5 is large, 0.3 is moderate, and 0.1 is small)?  For example, if 90% (or only 30%) of observations fall within one standard deviation from the mean, is that uncommon or completely unremarkable?


I have a fileserver where df reports 94% of / full. But according to du, much less is used:  # df -h / Filesystem            Size  Used Avail Use% Mounted on /dev/sda3             270G  240G   17G  94% / # du -hxs / 124G    /   I read that open but deleted files could be responsible for it but a reboot did not fix this.  This is Linux, ext3.  regards


Suppose that G is a finite group of even order. Show that G must contain an element $a\ne e$ for which $a^2 = e$

Suppose that $G$ is a finite group of even order. Show that $G$ must contain a non- identity element a for which $a^2 = e$.


Light pulses and energy-time uncertainty principle

Suppose we have a monochromatic light beam. We put an obstacle between source and observer and remove it repeatedly by certain frequency such that observer sees an oscillating intensity of light. Will the observer see different frequencies or only the original frequency? Does the energy-time uncertainty principle apply in this case?


i cant understand the way of forming the mysqli query when variables are involved. I have been trying for days different ways modifying it but getting all the time the very same error SQLSTATE[42000]: Syntax error or access violation: 1064. Can anybode help me telling what is wrong with this line of code when the firt variable is a string, as the second as well...?  `$tablename = 'sofka'; $sql = "INSERT INTO " . $tablename . " (" . $columns[1] . ") VALUES (" . $columnsval[1] . ")";`


Why does this proof work: Closed unit ball in $C_0$ is not compact

I know that this question has been asked to death, and multiple solutions are given, but I still don't understand why the "standard" proof works  Following     Let $C_o([0,1])$ be the space of continuous functions on $[0,1]$. Define $\|f\| = \sup\{|f(x)| x \in [0,1]]\}$  Let $B[0,1] = \{f \in C_o|\|f\|\leq 1\}$, show that this Closed, Unit ball in $C_o$ is not compact.  Proof Sketch:     Let $\{f_n\} \subset C_o, f_n = x^n, x \in [0,1]$, then $f_n \in C_o,  \|f_n\| = 1 \thinspace \forall n$, so $f_n \in B([0,1]) \thinspace \forall n$      But $f_n \to f \notin C_o$. So $B([0,1])$ is not compact.   Three questions:    if $f_n \to f \notin C_o$, wouldn't that mean $B([0,1])$ is not closed in the first place (contradicts with assumption)? How does the above implies that no subsequence converges in $B([0,1])$ Is the proof sketch essentially correct?


How to retrieve table attributes in PostgreSQL?

So I'm very new to PostgreSQL (and SQL as a whole) and I'm trying to find a way to view all attributes of a table. For example, say you have a table called "movies", I would like to see what attributes it has (e.g. movie_name, release_year). I'm sure there is a simple command for it, but I couldn't find it. Thanks in advance for any help!


Bonus Spell Explanation with Empower Spell Feat 3.5e

I'm very new to the spellcaster archetype in D&D. I've been playing rogues exclusively in 3e and 5e in every one of my campaigns, so yeah.  I'm playing a level 3 bard with 17 charisma. I only know level 0 and 1 spells.  In terms of bonus spells, with the feat empower spell, can I cast an empowered level 0 using a level 2 slot, since my character has a bonus level 2 spell slot and empower increases the spell level by 2?


How can I tell which size chain my bike uses?

After learning how to break a chain and reattach it, and also how to add and remove a master link, I find that I can now do much more in the way of maintenance at home. I'll no longer need to bring my bikes into the shop simply for a new chain... if I can only figure out how to identify what size chain I'll need to order.   Is there a simple way of telling what size and type of chain I'll need to order to replace the chain on a bike? Do I measure the chain links? Count links? Count gears on the cogs?   If it helps, some of my bikes' drivetrains have internal hubs, some have derailer gears.


Can I add random @Override annotations to a java fxml controller?

Was marked as duplicate, but still: my question does not refer to override annotations in general, but specifically in fxml controllers.   I am pretty new to java and trying to build a fxml application. I want to add an @Override annotation to a java fxml controller, but I am getting the error message "error: method does not override or implement a method from a supertype", and I cannot figure the origin of the mistake.   The same annotation can be used without any problem to the main java document, so I don't why it is not possible in the controller. The function only is effective once used with the @Override annotation, so commenting it out makes the function useless.   Is is impossible to use additional @Overrides in the controller, or is it a matter of handling them correctly?  public class Main_FXMLController implements Initializable {   private Button button;  @FXML private void handleButtonAction(ActionEvent event) throws IOException {           System.out.println("You clicked me!");             Platform.exit();  }    // I am trying to add to @Override annotation here, but it returns " method does not override or implement a method from a supertype"  @Override  private static void test () {      System.out.println("Test");   }   @Override public void initialize(URL url, ResourceBundle rb)  {  }


How can I match filenames that start with a given string using a RegEx in JavaScript?

I am looking for a JavaScript RegEx that matches all woff and woff2 files that start with a particular String, i.e. MyFont.  The following examples should match:  MyFont-bold.woff MyFont-light.woff2   The following example should not match:  GoogleFont-bold.woff SomeOtherFont-light.woff2 MyFont-something.css


Data Explorer returns "Captcha Shutdown" warning

I tried to execute  Data Explorer query and instead of the usual Captcha message I got the following:        V1 shutdown on 2018-03-31   Direct site owners to    Who needs to know about this so the problem can be fixed?


Show that if $A$ is closed and $A+A=2A$ then A is convex.

I found a solution to this problem but I am not sure of one of the steps. First let $a,b,c \in A$ then $a+b=2c$ thus $a/2+b/2=c$. We can continue this process to show that $\frac{1}{2^n}a+(1-\frac{1}{2^n})b \in A$ However, I am not sure how to conclude that $\frac{k}{2^n}a+(1-\frac{k}{2^n})b \in A$ for $k \in \mathbb{N}$ $0\leq k\leq 2^n$. I was thinking induction but i am not sure how. It is easy to show it is true for $n=1,2$ then assume it is true for $n$. I can show that $0\leq k\leq2^n$ works for $n+1$ but I do not know how to extend $k$ to $2^{n+1}$


Introduction:  I am trying to make a simple for in a row game using python. For one of my modules I need the computer to randomly choose a character to insert in the playing grid. I would like to have more control over the odds of what character is chosen.  Python Version:  3.4  Scenario 1:  Call random.choice("XO ")  Scenario 2:  A quick hack to manipulate the odds  Call random.choice("XXOO ")  What I want:  A solution that increases the chances of an "O" or "X" being chosed, decrease the chance of an " " (whitespace) being chosen  What I don't want:  Adding in more characters of the "O"s and "X"s to increase the odds. E.g. "XXOO " would give me 2:1 odds for the "X"s and "O"s This seems like a bad hack


How to chart multiple timelines in Excel?

I need to make a graph in Excel of people's time serving in a position, their start date to end date.  I'm trying to get their names on the Y axis, and then a horizontal line for each name running from their start date to their end date.  I can't figure out how to create this type of chart.


The first equation of motion is $v = u + at$. The second equation of motion is $s = ut + \frac{at^2}{2}$. If we divide the second equation of motion by time $t$, why don't we get the first equation of motion where has $1/2$ come from?


Are there any shortcut keys for responding to meeting requests in MS Office Outlook 2010?

I am quite proficient with the keyboard and try to only use the mouse when necessary. Given that context I was very familiar with the shortcut keys in MS Outlook 2003 and never needed to use the mouse to use that product. Now my company has recently upgraded to MS Outlook 2010 and I am finding it impossible to operate it without having to use the mouse. In particular replying to meeting requests with the old shortcut keys no longer seems possible.   I have held down the ALT key and sometimes it shows some shortcuts on the ribbon but this seems to be limited to ALT+H which tends to alternate between designating "Accept" and "Tentative" without any keys for the other options. Also as this appears to switch between "Accept" and "Tentative" one can't even use this consistently without first having to check what it means for each particular instance.  Any help with this would be greatly appreciated!


Registering a new tag / using SO-infrastructure for own project's Q/A

I will release my framework to the open source world on github and expect new users to have questions about it. I've never been a big fan of mailing lists, however, a big fan of SO.  Does SO want me to use their infrastructure for Q/A about my framework? I'd need a tag on SO, so I could register for all questions about the framework. I would also write a lot of self-answered questions in order to create a FAQ for my users without having my own infrastructure.  My advantages: no maintaining of my own forum software / bugfixes / security / whatsoever. SO advantage: if the framework hits off -> lots of clicks here  Is it "ok" with the administration if I start to write self-answered Q/A about my framework here and ask for a tag as soon as I have like 10 to 15 articles ready or is this non-favored behavior?


Solvable Lie algebra with codimension 1 ideal

There is an exercise in Humphreys's An Introduction to Lie Algebras and Representation Theory: "Any nilpotent Lie algebra contains a codimension 1 ideal".  The proof I am thinking of is the following.  Suppose the Lie algebra $L$ satisfies $L\neq[L,L]$. Then $\pi\colon L\to L/[L,L]$ is a projection onto an abelian algebra. Choose a codimension 1 subspace $I\subset L/[L,L]$. Then $I$ is an ideal and its preimage $\pi^{-1}(I)$ is necessarily an ideal in $L$, because any subspace containing the derived algebra is an ideal. Moreover, $\pi^{-1}(I)$ has codimension 1. $\square$  The only condition on $L$ is that $L\neq[L,L]$, which holds for solvable Lie algebras as well. Is this proof correct? How come Humphreys didn't set the exercise with "nilpotent" replaced by "solvable"?


How do I detect a custom named item in a chest in 1.16?

I've been trying to make a command block that detects when a certain item that has a specific name is placed inside a chest. So far, I've been able to detect when a specific item is in the chest, but without any luck for the custom name. My functioning command is: /execute if block X Y Z minecraft:dispenser{Items:[{id:"minecraft:cobblestone"}]}  I've tried variations of /execute if block -10 71 -54 minecraft:dispenser{Items:[{id:"minecraft:cobblestone"}],tags:{display:{Name:"(name)"}}}  So far nothing involving testing for the item name has worked. How do I make a command to detect a custom named item?


Find the limit: $\lim \limits_{x \to 1} \left( {\frac{x}{{x - 1}} - \frac{1}{{\ln x}}} \right)$

Find: $$\lim\limits_{x \to 1} \left( {\frac{x}{{x - 1}} - \frac{1}{{\ln x}}} \right) $$  Without using L'Hospital or Taylor approximations  Thanks in advance


Can Fermat's last theorem be proven false with complex numbers?

Fermat's famous last theorem (a^n + b^n ≠ c^n, for n > 2) so far holds true.....with real numbers. I was wondering if it could be false if one extended it to complex numbers, that is, (a+bi)^n + (c+di)^n = (e+fi)^n... I have tried to weaken the problem by assuming that n is 3 and that (a+bi) = (c+di) (for the Pythagorean theorem, it is valid to have two sides of the same length, and if one can prove the theorem false for two of the same complex number, it is still a valid counterexample). Knowing that, I expanded 2(a+bi)^3 = (e+fi)^3 out into a nightmarishly long cubic equation, but now I am stuck because I am not sure how to simplify or combine both sides or even how to go about it. I did take a look at the complex plane, and tried cubing the simple complex number 2+i, which turns out to be 2+11i. Then I picked another complex number, cubed it, added the two numbers together and I got a number that does not have an integer cubed root. That was just trial and error, though, not a very mathematically sound method, just looking for any patterns.  My hope is that if the theorem can be proven false for n=3, can it be for 4? 5? Any other value of n?


What can I use as the generic term for "a function that is composed with another"?

Suppose I am talking about the composition $g \circ f$ (or more generally $f_n \circ \cdots \circ f_1$). Is there a generic term for the functions $f$ and $g$ (the functions $f_i$)?  "Compositand"?


Is there a convenient way to classify files as "binary" or "text"?

Standard Unix utilities like grep and diff use some heuristic to classify files as "text" or "binary".  (E.g. grep's output may include lines like Binary file frobozz matches.)  Is there a convenient test one can apply in a zsh script to perform a similar "text/binary" classification?  (Other than something like grep '' somefile | grep -q Binary.)  (I realize that any such test would necessarily be heuristic, and therefore imperfect.)