I am a Vietnamese national, who is studying in Nicosia, Cyprus since June 2016, in a four-year Bachelor's degree program in business administration. My application for UK tourist visa was submitted on 13 December 2016 and was refused on 20 December 2016.  Submitted document list:    Student residence permit (valid until 05 June 2017)  College registration letter  College holiday letter  Student card  Six months bank statements (including 3 receipts of money transfers from mother in Vietnam)  House contract (for 2 years until June 2018)  Air ticket reservation  Hotel reservation Travel insurance    Included mother's documents as follows:    Business license  Tax for the last three month Annual tax  Sponsor letter   Property in mother's name   Bank letter with balance equal to 12,000 Pounds (which issued from 01/03/2016-01/03/2017)  My birth certificate      The decision: You have applied for an entry clearance as a General Visitor to the United Kingdom for 6 days and propose tourism.       You have declared that you are a student and not employed. Whilst you have   included customer credit transfers these do not evidence the original source of the funds, I am therefore not satisfied that your circumstances are such that you would leave the UK if admitted.       You state that you spend between 600-650 pounds per month on living costs, you have not demonstrated how you support yourself and the source of the funds. You state that you will have 2500 pounds available for your trip. Given your financial circumstances, balanced against your proposed expenditure I am not satisfied that you would leave the UK if admitted.      The financial documents you have submitted do not show the origin of the funds and therefore I am not satisfied that they are genuinely available to you. From the information declared on your application form and the documents submitted, you have not shown that you will be able to maintain and accommodate yourself during your proposed visit in the UK your application has therefore been refused under paragraph V4.2（e)   The customer credit receipts reflected on my bank statement are transfers from my mother for living expenses. Why was the ECO confused about where the funds originate? What should I do in the next application？


MySQL - Selecting data from multiple tables all with same structure but different data

Ok, here is my dilemma I have a database set up with about 5 tables all with the exact same data structure. The data is separated in this manner for localization purposes and to split up a total of about 4.5 million records.  A majority of the time only one table is needed and all is well. However, sometimes data is needed from 2 or more of the tables and it needs to be sorted by a user defined column. This is where I am having problems.  data columns:  id, band_name, song_name, album_name, genre   MySQL statment:  SELECT * from us_music, de_music where `genre` = 'punk'   MySQL spits out this error:  #1052 - Column 'genre' in where clause is ambiguous   Obviously, I am doing this wrong. Anyone care to shed some light on this for me?


First-time poster. I hope I am posting appropriately and following protocol. I looked at the other sections and this seemed to me to be the correct place. Very quick and simple question. Hyphens are always rather tricky for me. Should the following be written as: "knowledge and detail-based approach" or "knowledge-and-detail-based approach" or "knowledge and detail based approach" Thank you!


I have a very simple question.  I'm wondering how to type a certain symbol in TeX.  I've never encountered this symbol before today, and even after perusing the list of TeX symbols I can't find it.  I saw a problem like this:  Add   $6<200^\circ-4<50^\circ$   Except instead of <200 the 200 was sort of... in the <.  Like the < was to the left and below the 200.  Imagine $\sqrt{200}$ but instead of a square root to the left and above, you have a < but to the left and below.  By the way, I tried Detexify.


A part of mesh turn into cyan in edit mode

I am a newbie in blender. I just had a trouble with modeling. I did a model in Zbrush, then I import that in maya to retopologize. then I import the retopologized model into blender. Problem is when I switch the mesh into edit mode, a part of mesh will become cyan color.  this is different from what I usually did.    Hanwen  Thanks


I'm using post thumbnails to link to a page.  Is it possible to add a class name to the post thumbnail image.
<a href="<?php the_permalink(); ?>" ><?php the_post_thumbnail(); ?>


Stackoverflow reputation - worth mentioning in personal statement?

It is going to be my last year in school, and I am thinking about studies abroad - I would love to study computer science. Lately, I started participating more in Stackoverflow, answering to PHP, MySQL, and HTML questions. If I manage to answer to a decent amount of questions(now I have 26, I am thinking about ~75-100) would it be worth mentioning in my personal statement (not the number, but that I am participating in the community, providing university with my nickname used here). I have other experiences that I am planning to write there:   I have taught people online of how to use microcomputers I have taught people of HTML basics I am writing my extended essay on computer science (I am attending IB diploma program)  I am currently working on quite a big project for my school using not spaghetti code, but a normal MVC architecture and OOP (at least, I am trying)   Is participating in Stackoverflow community worth mentioning among these (or maybe it is even stronger than what I mentioned?), or not?


I am macOS rookie and now have difficulties with Safari, I would like to find how I can save tabs?   For example some tabs were open, than I close Safari and turn off laptop, next time when I turn on laptop and open Safari I would like my tabs restored and open again...


What is the best practice for creating unique compound primary keys in salesforce?

I have a custom object in salesforce where I want to enforce uniqueness across two lookup fields and a date field.  I do not want to allow two records to have all three of those fields in common, but if any one is different, then it is ok.  Is there an accepted best practice for achieving this?  I've thought of a few ways to accomplish this, but I want to do it "right".   Create another field on the record that is a concatenation of all three fields. Use a workflow rule to populate it every time a record is created and check the unique checkbox on that field. Try to accomplish this with a Validation Rule.  (I've tried a few things here, and didn't have much luck.) Write a full-blown bulkified trigger specifically for this instance.  (This seems like a little bit of overkill to do something so standard)   Any comments on these methods or other ones I haven't thought of would be greatly appreciated.


Do you capitalize counties in this sentence?

Do you capitalize "counties" in the following sentence. Sebastian and Forrest counties are represented.


Does the square of uniform distribution have density function?

$X\sim U[0,1]$ and $Y\sim U[-1,1]$ are two uniform-distributed R.V.'s. Are $X^2$ and $Y^2$ still uniform? Do they have explicit probability density funtion?


Formatting a line between a Figure and a caption

I was perusing through thesis and came across the following formatting (as shown in the picture attached) where there is a line separating the figure and its caption.  I really like this formatting, but have no idea how to actually reproduce it. I am currently using the following preamble,  \documentclass[12pt]{article} \usepackage{graphicx} \usepackage[margin=1 in]{geometry} \usepackage{amsmath,amsfonts,amsthm,amssymb} \begin{document} ... \end{document}   Any help would be appreciated.


I am trying to write a program in which I am interfacing a switch and a LED. I want a program so that when I press the switch the LED turns on and when I press again that led turns off. Right now I have made a program in which when I press the switch the LED turns on and then goes off.  void main() {     DDRA=0x01;  // Interfacing LED at PORTA.0     DDRB=0xFE; // Interfacing Switch at PORTB.0     PORTB=0xFF;      while(1)     {         if(PINB==0xFE)         {             PORTA=0x01;         }         else         {             PORTA=0x00;         }     } }


Prove that $f'(0)$ exists and $f'(0) = b/(a - 1)$

Problem:   If $f(x)$ is continous at $x=0$, and $\lim\limits_{x\to 0} \dfrac{f(ax)-f(x)}{x}=b$, $a, b$ are constants and $|a|>1$, prove that $f'(0)$ exists and $f'(0)=\dfrac{b}{a-1}$.   This approach is definitely wrong:    \begin{align} b&=\lim_{x\to 0} \frac{f(ax)-f(x)}{x}\\ &=\lim_{x\to 0} \frac{f(ax)-f(0)-(f(x)-f(0))}{x}\\ &=af'(0)-f'(0)\\ &=(a-1)f'(0) \end{align}  I will show you a case why this approach is wrong:     \[f(x)= \begin{cases} 1,&x\neq0\\ 0,&x=0 \end{cases}\]   $\lim_{x\to0}\dfrac{f(3x)-f(x)}{x}=\lim_{x\to0} \dfrac{1-1}{x}=0$   but $\lim_{x\to0}\dfrac{f(3x)}{x}=\infty$,$\lim_{x\to0}\dfrac{f(x)}{x}=\infty$   Does anyone know how to prove it? Thanks in advance!


What is causing this Kernel panic (Unable to mount root fs)?

I have a simple question for the gurus... How bad is this?    A few days ago I was using my laptop and next day I have this on the screen. So I installed the HDD on my desktop to see if I can get all my stuff from the disk, but I can't. This is the message when I try to boot with this HDD.


Passing Reference changing the code in java

If java is Pass By value Only Than why here its changing the value in list   I tried with Object also   public static void main(String[] args) {     List<Integer> list = new ArrayList<>();     list.add(12);     list.add(15);     list.add(45);     addExternally(list);      ListIterator<Integer>      iterator = list.listIterator();      while(iterator.hasNext()) {          System.out.println("Value is : "                 + iterator.next());      } }  private static void addExternally(List<Integer> list) {      list.add(11);      list.add(12);  }   it should not take the changes from addExternally method but its taking why


list dependencies of all packages installed in ubuntu 16.04?

I have read that apt-cache depends  lists out the dependencies on package_name,however, is there a way I can list out all the dependencies of all the packages in a single command ( something like, apt-cache depends all ) ? Thanks in advance.


Complete balanced (signed) residue System of an odd modulo m

Show that if $m$ is odd then $\frac{(-m+1)}{2}, \frac{(-m+3)}{2}, \cdots, \frac{(m-3)}{2}, \frac{(m-1)}{2}$ is a complete residue system modulo m.  I understand the definition of a complete residue system but is having a hard time incorporating the odd part of this statement.


What to call "Cancel" when "Cancel" is already the default action?

When attempting to cancel a service or setting, "cancel" is the default action. What should the normal "cancel" button be called?  Redbox uses a playful "just kidding", which may not be appropriate in all circumstances.


I've always have been in servers on HiveMC.com And then when i was playing a game of cowboys vs indians, my skin turned into a steve some one please help!


Electrostatic field-Field lines relationship

How is the $\frac{1}{r^2}$   dependence of the electric field intensity due to a stationary point charge consistent with the concept of field lines?


re.match in AT content calculator not working

Working out a few kinks in this code and for some reason my method validation check is not quite working. All I want it to do is to validate that the input from the user ONLY contains letters G, C, A, T before moving onto the method at_calculate which performs the maths on the input sequence. Any help/tips would be appreciated.  import re  from tkinter import *  class AT_content_calculator:      def __init__(self, master):         #initialising various widgets         frame_1 = Frame(master)         frame_1.pack()          self.varoutput_1 = StringVar()          self.label_1 = Label(frame_1, text="Please enter a DNA sequence:")         self.label_1.pack()         self.entry_1 = Entry(frame_1, textvariable=self.dna_sequence)         self.entry_1.pack()         self.output_1 = Label(frame_1, textvariable=self.varoutput_1)         self.output_1.pack()         self.button_1 = Button(frame_1, text="Calculate", command=self.validation_check)         self.button_1.pack()      def dna_sequence(self):         self.dna_sequence = ()      def validation_check(self):         #used to validate that self.dna_sequence only contains letters G, C, A, T         if re.match(r"GCAT", self.dna_sequence):             self.at_calculate()         else:             self.varoutput_1.append = "Invalid DNA sequence. Please enter again."             self.validation_check()      def at_calculate(self):         #used to calculate AT content of string stored in self.dna_sequence         self.dna_sequence = self.entry_1.get()         self.total_bases = len(self.dna_sequence)         self.a_bases = self.dna_sequence.count("A")         self.b_bases = self.dna_sequence.count("T")         self.at_content = "%.2f" % ((self.a_bases + self.b_bases) / self.total_bases)         self.varoutput_1.set("AT content percentage: " + self.at_content)  root = Tk() root.title("AT content calculator") root.geometry("320x320") b = AT_content_calculator(root) root.mainloop()


What’s the temperature at the Schwarzschild “radius”?

Imagine a foolish astronaut who travels into a Schwarzschild black hole. It’s thought that there’s nothing special about the geometry he encounters at the Schwarzschild “radius” (OK, maybe some serious tide). But suppose he has a thermometer. What temperature does he measure? You may assume the thermometer is either a radiometer pointed toward the black hole, or a radiometer that averages over all directions.


Story of a time traveller meeting himself repeatedly

I read this story in the 70s or 80s (it might however be older). I think it was a short story, and not a novel.  These are two scenes I remember:  In the beginning of the story a guy (lets call him Albert, not the real name) sits in a room, when suddenly a disk appears and somebody (Balbert) drops through it (it turns out it is Albert himself). Soon after this a third guy (Calbert, again an older version of Albert) appears, they all struggle a bit and then Albert falls through the disk (and into the past to appear as Balbert).   Somewhere in the story he reaches some kind of far future where he meets an old man (which later turns out to be Albert again) who explains him how to operate the machines.


Is it required to use a random IV for AES-CBC with random key per message?

I'm developing a program to encrypt and decrypt a file with AES-256/CBC in Java. And I want it to be safe enough. In my case, I generated random AES key for each file to encrypt and decrypt them.  My question is if it is necessary to generate a random IV for encrypt/decrypt or it is already secure enough with a random AES key and fixed IV.


I think the strategy for this problem would be i assume some arbitrary element is in gcd(a,b) and chase it into the rhs and then do it the other way around , but i am not sure how to even start this one.


Index under sum symbol below following equation

I have a sum symbol with a quite long index underneath. This produces too much space between the following signs.  \begin{equation}  \sum_{X\leq-VaR_\alpha(X)}{P(X)\cdot x}  \end{equation}   I would like to see the index to reach under the P(X)x but in a very specific way: The X in the index should be left-aligned with the \sum symbol and any overlap of the index on the right of the symbol should displace the operand.  Is there any way to do this? I don't want to use a two lines index.


How to import a digital elevation model in Germany Gauss Krüger from .dat file?

i am very new to qgis. I want to create a hillshade file and also calculate the inclination.  The structure of the digital elevation model data looks like this:  5390.0125 5659.9875 251.8 5390.0125 5659.9625 250.6 5390.0125 5659.9375 247.5 5390.0125 5659.9125 240.6 5390.0125 5659.8875 236.1 5390.0125 5659.8625 234.8 5390.0125 5659.8375 235.6   The file format is *.dat. The coordinate system is Gauss Krüger, Bessel, 5. meridian.  I have no idea how to import the data in qgis.


Is it possible to mount iSCSI on multiple machines?

I have a freeNAS setup with iSCSI attached to my Windows machine. That servers me great cause I get all the ZFS features and easy reconnecting in Windows - Don't have to mess around with SMB mappings and reconnect issues constantly.  I have tried to search for setting up iSCSI to allow for multiple connections. Generally people say its a bad idea.. but maybe you it can be done with multipath or some other way?


What is the half-life threshold for an isotope to be considered stable?

What minimum half-life an isotope should have to be considered stable?


The zeros are $\{2 \pi i n ,n\in \mathbb{Z}\}$. They are all simple. The function is of order 1. Hence, the factorization should be   $$ e^z - 1 = e^{p(z)} z \prod_{n=1}^\infty (1 + z^2/4n^2\pi^2) . $$  The problem left is to determine the polynomial $p(z)$, which is at most first order.   But how to proceed?


How prove this inequality $x^3y+y^3z+z^3x\ge xyz(x+y+z)$

Let $x>0$, $y>0$ and $z>0$. Show that   $$x^3y+y^3z+z^3x\ge xyz(x+y+z).$$   I known we can't WLOG: $x\ge y\ge z$, if this, I can use rearrangement inequality, But other I can't it. Thanks?


Counting the instances of specific words in a text, using awk

If I have a file words_of_interest.txt with one word per line, is there a way to use awk (or some other *nix tools) to obtain the number of times each of these words occurs in another text file my_text.txt, using only one pass?  Currently I am grep -c'ing  the text for each word, but this is quite slow because the text is large, and there are several hundred words to search for.  EDIT: providing sample input and output:  [words_of_interest.txt] joe hi  [my_text.txt] hi joe hi jack nice day today  [output] joe 1 hi 2   EDIT2: To those who marked this question as duplicate: the  is about counting all the words, whereas this one is about counting only the instances of a specific pre-defined set of words.


Image upload button unresponsive when failed URL upload

When using the image upload/embed feature and using the "link from the web" feature with an URL that fails (see image below) the large "Drag and drop or click here" box does not respond to clicks until the "Close" link it clicked. Note that dragging an image does work, even when the "Failed to upload image; the format is not supported" error is displayed.


I have recently dual booted ubuntu 14.04.2 LTS alongside window 7 in my dell laptop from live usb flash drive.  The dual boot was working until I deleted empty partition (not ubuntu or window partition) and merged it with anouther. When I restarted it displayed the following: error : unknown filesystem. Entering rescue mode... grub rescue> Did I mess with my OS or what? How can I recover to have dual boot again?


Central AC is Icing up, but not cooling my house

My central air conditioner isn't cooling like it used to. I noticed that the refrigerant lines entering the evaporator coil in the plenum were icing up. What might the problem be?


Correct format to combine text and columns to create a new column?

Long story short, my company's system creates a "keyword search" column when we enter in new stores manually. When they need to add 100's of stores, they have me insert everything via SQL. I can do everything except create a very long and odd column that the system uses as a search field for end users. I've been using excel to combine all of the columns, but it's extremely time consuming. I'm hoping someone can share some insight in to how to create this column using SQL so I can eventually automate this entire process. I'm a newer DBA and newer to this site so bare with me please lol.  Table is like:  CustNo | Name | City | Zip ______________________________ 100 | New Store | Miami | 33101  101 | Store 2 | Miami | 33102   I need to add a column that uses those fields and combines my own text input. End result is like;  SScustno100 100 SSnameNew_store New store SScityMiami Miami SSzip33101 33101     So query would be similar to:  "SScustno"[custno] [custno] "SSname"[name] [name] "SScity"[city] [city]  "SSzip"[zip] [Zip]   The later is a better reference. How would I write a query that combines my text input and the columns in the table to combine everything together to create the "keyword search" field for each record? I feel like this should be easy, but I've tried a few times and I've concluded I just don't know the correct syntax to work off of.  Any help is greatly appreciated. If you need more info I'm happy to provide it. I tried to dumb it down as best as I could. The actual column I create in excel combines 120+ columns, but I'm not putting that mess on you guys. I just need a way to combine my text and column data together in order to insert it into a new column.


Finding all integer solutions to the Diophantine Equation: $ax+by=c$

I am not sure how to prove this theorem. It states: Let $a,b,c$ be integers with $a$ and $b$ both no equal to $0$. If $x=x_0$ and $y=y_0$ is an integer solution to the equation $ax+by=c$, that is, $ax_0+by_0=c$, then for every integer $k$, the numbers $$x=x_0+\frac{kb}{(a,b)}\,\,\,\,\&\,\,\, y=y_0-\frac{ka}{(a,b)}$$ are integers that also satisfy the linear Diophantine equation $ax+by=c$. Moreover, every solution to the linear Diophantine equation $ax+by$ is of this form. I understand how all solutions for a particular equation can be found using this equation, but I do not know how I can go about proving this theorem. Example: Find all solutions to the equation $24x+9y=33$. The obvious solution to the equation is $x_0=1$ and $y_0=1$. Then, $x=1+\frac{9k}{3}$ and $y=1-\frac{24k}{3}$, so we have, $x=1+3k$ and $y=1-8k$ hence for all integer values of $k$, we have corresponding $x$ and $y$ values which satisfy the equation.


Price String spliting into amount and currency

I need help splitting string in javascript.  I have a string with currency. The string depends on the location.   For example: "1,99€" or "$1,99"  I would like to split the string and extract the "amount" and the "currency" out of it.   If this fails, I would like to return an empty string or just null.  Does someone know how to solve that?


Can't swich between Ubuntu and Microsoft and am stuck in Ubuntu. Please help!

In order to switch to Microsoft Windows 8.1 from Ubuntu I would go into my BIOS and click F8 to get to a menu where I can pick what to boot from. I clicked on my hard drive(were I have both Ubuntu and Windows) as usual. After that it should have gone into another menu were I could choose which operating system I wanted to boot into, but it didn't and it went straight into Ubuntu I am trying to fix it and so I went into settings and when I clicked on the section that shows the hard drive space partitioned for Windows it said this:  Unable to access "649 GB Volume"  Error mounting /dev/sda2 at /media/jd/543652053651E88E: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda2" "/media/jd/543652053651E88E"' exited with non-zero exit status 14: Windows is hibernated, refused to mount. Failed to mount '/dev/sda2': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.   Does anyone know how I can fix this so I can get back into windows?


onchange not working in jquery appendTo()

I am new to jQuery and have been trying to create a dynamic drop-down-menu using select. However I am unable to use onChange in appendTo. Any Suggestions ?  <script> $(function() {     var addDiv = $('#content');     var n = 1;     jq144('#add_match').live('click', function() {         $('<p ><select onchange = "showUser(this.value, "select_team_' + (n) + '")" name="select_team_' + (n) + '" id="select_team_' + (n) + '"><option value = "">Team 1</option><option value = "a">A</option> <option value = "b">B</option><option value = "c">C</option></select> </p>').appendTo(addDiv);     ++n;      }); }); </script>   I also tried using on() but am unable to pass parameters to it.  Here is showUser:  <script>     function showUser(str, select_name) {         var num = parseInt(select_name.substr(select_name.length - 1));         alert(num + 1);         if (window.XMLHttpRequest) {             xmlhttp=new XMLHttpRequest();         } else {            xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");         }         xmlhttp.onreadystatechange=function() {             if (xmlhttp.readyState==4 && xmlhttp.status==200) {                 $("select[id='select_team_" + (num + 1) + "']").html(xmlhttp.responseText).selectmenu( "refresh");             }         }         xmlhttp.open("GET","getplayers.php?q="+str.value,true);         xmlhttp.send();     } </script>   Finally I was able to solve the problem using .on().


Do permanent negative levels take away class abilities?

Lets say I am a level 20 monk of the four winds and I have just been resurrected by my 20th level ability. Now, since this ability gives two negative levels, would my 20th level ability still function?


I already know that when I standing  on weighing machine it's measuring my mass not my weight, but when I take the same machine to moon it's will read different value. According to my information that the mass is constant! How does it change? You will answer me because it depends on gravity.  I said to you so we must  consider it weight not mass because mass is constant and not change with gravity force!


In the switch statement, when i have a case with "||" it doesn't work properly.  $get = 'item'; switch ($get):  case 'items' || 'several-items':     echo 'items';     break;  case 'item':     echo 'item';     break;  endswitch;   This code outputs items. Is this a php bug ?  $get = 'several'; outputs items too.  So the problem is definitely with the '||' operator, because the following code works just fine:  $get = 'item'; switch ($get):  case 'items': case 'several-items':     echo 'items';     break;  case 'item':     echo 'item';     break;  endswitch;


Mysql inserts data to mysql database everytime i reload page

I have done that when I push button it should insert data into mysql database but it only inserts it when I reload page. Here Is the code:  <script> function minuscredits() {     alert("hah");     <?php     mysql_query("UPDATE `users` SET credits=credits-1 WHERE user_id=".$_SESSION['user']);     ?> } </script>   When I push button I get alert but not insert into database only if I reload page it inserts successfully.


The task is to compute the area of a triangle in a 3 dimensional space who is defined by those 3 points:  $$A=(1,1,1),  B=(1,2,0), C=(2,1,2)$$  The problem is that the formula I know would compute me the volume of the triangle.  The formula is the determinant of $([A][B][C])$ where $[V]$ represents V in the standard base. The area of a triangle is computed as half the area of a parallelogram.


What is the difference between “within” and “inside”?

Here is the definition of the word within from Oxford Dictionary:     inside (something)   So does that mean the two words have no difference, and can be used exchangingly? Is there any connotation that one word can be used but not the other?


Click on button with jQuery doesn't have action

I'm stuck with an button, and can't understand why it isn't work.   $('#full-london').on('click', () => { weatherPage.render('London'); });   '#full-london' is id of my button  weatherPage.render starts some jQuery code witch change my front page. This is tested in other case and it work correct.   This is the button:  Full forecast   Any idea what is wrong?   Here is additional situation with search button who uses weatherPage.render and it work:  $('#search-city-button').on('click', () => {     const searchString = $('#search-city-input').val();     weatherPage.render(searchString); });   searchString is search input
       <input type="text" id="search-city-input">       Search
   Here is what is weatherPage.render(); do


Difference between wiring events with and without "new"

In C#, what is the difference (if any) between these two lines of code?  tmrMain.Elapsed += new ElapsedEventHandler(tmrMain_Tick);   and  tmrMain.Elapsed += tmrMain_Tick;   Both appear to work exactly the same. Does C# just assume you mean the former when you type the latter?


Diagonalizable matrices with complex values are dense in set of $n\times n$ complex matrices.

My linear algebra professor proved that      Diagonalizable matrices with complex values are dense in set of $n \times n$ complex matrices.   He defined a metric (I believe) that was somehow related to the usual metric on $\mathbb{R}^{n^2}$.  Then somehow proved that diagonalizable matrices were dense because for any matrix $A$ if $\det(A - \lambda I) = 0$ on an open subset, then $\det(A - \lambda I)$ was the zero polynomial.  I Googled around a bit and found some stuff talking about the Zariski topology, and I am not sure this is what I want. Most of what I have found on this topology is much more general than what he was doing.  Does anyone know any resources that would explain how to go about proving this statement?  Edit: I found out how to prove this the way my professor did.  We define the norm of a matrix by $$ |A| = \max\{|Ax| : |x| = 1 \}.$$ Now we have a distance $d(A, B) < \epsilon$. You can prove that if $(A - B)_{ij} < \epsilon/n$, then $|A - B| < \epsilon$.  Let $p(x)$ be the characteristic polynomial of $A$, an $n \times n$ matrix.  $$p(x) = \prod_1^n (x - x_i) = x^n + (-1)\sigma_1 x^{n - 1} + \cdots + (-1)^n\sigma_n$$ where $\sigma_1, \ldots, \sigma_n$ are the elementary symmetric polynomials of $x_1, \ldots, x_n$ which are the eigenvalues.  The discriminant of the characteristic polynomial is a symmetric polynomial, therefore it can be written in terms of the elementary symmetric polynomials, which in turn can be written in terms of the entries of the matrix.  But since the discriminant is a polynomial, it only has finitely many roots. Therefore for $\epsilon > 0$, by changing the entries of the matrix less than $\epsilon / n$ we can find a new matrix $B$ such that $|B - A| < \epsilon$ and the discriminant is not zero.   The discriminant being not zero means $B$ has distinct eigenvalues, thus has a basis of eigenvectors. Therefore, it is diagonalizable.  Thus the set of diagonalizable matrices is dense in the set of matrices with respect to that metric.


How can I reduce the size of bundled Unity DLLs on Android?

I have created a simple project (I am a Unity beginner) for Android but the apk size is around 18 MB!  I checked the documentation. One way to decrease the apk size is to check the editor log. Then I discovered that imported DLLs have a size of 3.9MB.  I only used UnityEngine and Collision packages. So how can I avoid to import the other big DLLs?


A and B flips a coin alternately. A starts. the one how gets `H` first - wins. what is the probability that B wins?

Giving the following question:  A and B flips a cion, alternately. A starts. The one who gets H first, wins. Let X be a random variable denotes the number of flips at the end of the game. Calculate: $P(X is even)  I found two approached that yields two difference solutions:   Let A flips a coin , and Let B flip a coin. (Assume A didn't win)  I'll call it a round. $round_i$ is independent. By a Tree, $P(A)_{head} = \frac{1}{2}$ and $P(B)_{head} = \frac{1}{4}$ When $X$ is even, it's $B$'s round and therefore answer is $\frac{1}{4}$.  Second approch is simply:  $\sum_{i=1}^\infty (\frac{1}{2})^{2i} \approx \frac{1}{3}$ For each 2 flips, or for each round, we have a probability of $\frac{1}{2}$ to get X even.  What is the right approach? If none of the above, that is the right approach? Thanks in advance.


I'm writing a python file that imports a method which I wrote. This method is still buggy, so I need to be able to edit it. The issue is if I edit the imported method, the file that is calling that method won't register any of the changes I've made. The only way I've been able to get the changes registered is to exit out completely (I'm using Enthought Canopy). I've tried clearing out all the variables with %reset, exiting all my open .py files, and then opening them again and running them. It doesn't work.  I can combine the two files so that the method is being called inside the .py file in which it is written, but as I will need the method for a lot of applications, this is only a short-term fix since I don't want any extraneous code in the file long-term.


Looking for a general proof of the Cauchy-Schwarz Inequality

I was reading the book Mathematics for Machine Learning by Marc Peter Deisenroth, Cheng Soon Ong and A.Aldo Faisal and came across this remark:  Remark(Cauchy-Schwarz Inequality). For an inner product vector space $(V,\langle\cdot,\cdot\rangle)$, the induced norm $||\cdot||$ satisfies the Cauchy-Schwarz inequality $|\langle x,y\rangle|\le ||x||\text{ }||y||$  Now I know how to prove this inequality for the dot product and the induced Euclidean norm. But I want to know if there is some general proof of this inequality that can show the truth of this statement for every possible inner product and induced norm. So, my question is whether such a proof exists, and if yes how it works(some clues, not the proof itself), or whether the inequality has to be proven separately for any considered inner product. Thanks for your time!


Menus, folders, programs are all hidden or invisible in Ubuntu 12.10

I have had problems with this laptop Aspire 4530 for the last 3 days.  I erased the last Ubuntu (several times) and all is the same: Ubuntu starts, but in the screen there is not a menu (in the left side (using Gnome Desktop)) and I can not see any program, application, internet, graphic, games, nothing. I neither can see any folder.  This is killing me for hours.  Any idea in how can I get those menus back?  Thank in advance


Sci-Fi TV Series identification from 90's

As a kid in 1993-1994, I watched some kind of Sci-Fi TV series about a guy who was turned into a machine. Or at least half of him was entirely a machine and the other was human, split vertically. I remember there was some kind of conflict between machines or a machine-like race and the protagonists of this series, which ended up with him turning into a half machine. Also, I remember the woman that loved that guy when saw him turned into a half robot/half man was shocked but touched his human side on a cheek and cried or something like that. It was a dramatic scene which was memorable. I don't remember anything else beside that and that the whole setting of series was on some kind of starship.   Also, not sure but I think series was produced by Disney, although I might be mistaken. And I think it was a miniseries, as the entire show was 6 episodes, each 45-60 minutes long.


Goodness-of-fit test in Logistic regression; which 'fit' do we want to test?

I am referring to the question and its answers:  by @Clark Chong and answers/comments by @Frank Harrell. and to the question  and the comments.    I have read the paper D.W. Hosmer, T. Hosmer, S. Le Cessie, S. Lemeshow, "A comparison of goodness-of-fit tests for the Logistic regression model",  Statistics in Medicine, Vol. 16, 965-980 (1997).    After reading I was confused because the question I referred to asks explicitly for "(probability) predictive ability", which is in my opinion not the same as what the goodness-of-fit-tests in the paper supra aim at:  As most of us know, the logistic regression assumes an S-shaped link between the explanatory variables and the probability of success, the functional form for the S-shape is   $P(y=1|_{x_i})=\frac{1}{1+e^{-(\beta_0+\sum_i \beta_i x_i)}}$  Without pretending that there are no shortcomings with the Hosmer–Lemeshow test, I think that we have to distinguish between tests for the (a) '(probability) predictive ability' and (b) 'goodness-of-fit'.    The former's goal is to test whether the probabilities are well predicted, while the goodness-of-fit tests test whether the S-shaped function above is the 'right' function.  More formally:    tests for 'probability predictive ability tests' have a $H_0$ stating that the success probabilities are well predicted by the model; while for goodness-of-fit tests $H_0$ is (see Hosmer et. al. ) that the S-shaped functional form supra is the correct one.  Hosmer et al. perform simulations where they find the power to detect two types of deviations from the null namely that the link function is wrong or that the exponent in the denominator is not linear.    Obviously, if the above function has the 'right' functional form (so if the tests concludes that we can accept $H_0$ for the goodness-of-fit test), then the predicted probabilities will be fine, ...  First remark  ...however, accepting the $H_0$ is a weak conclusion as explained in .   First question  The most important question/remark that I have is that if the goodness-of-fit $H_0$ is rejected, then the conclusion of the test is that the functional form was not the 'right' one, however, does this imply that the probabilities are not well predicted ?  Second question  Furthermore, I want to point to the conclusions of Hosmer et. al; (I cite from the abstract):   ''An examination of the performance of the tests when the correct model has a quadratic term but a model containing only the linear term has been fit shows that the Pearson chi-square, the unweighted sum-of-squares,the Hosmer-Lemeshow decile of risk, the smoothed residual sum-of-squares and Stukel’s score test,have power exceeding 50 per cent to detect moderate departures from linearity when the sample size is 100 and have power over 90 per cent for these same alternatives for samples of size 500. All tests had no power when the correct model had an interaction between a dichotomous and continuous covariate but only the continuous covariate model was fit. Power to detect an incorrectly specifed link was poor for samples of size 100. For samples of size 500 Stukel's score test had the best power but it only exceeded 50 per cent to detect an asymmetric link function. The power of the unweighted sum-of-squares test to detect an incorrectly specifed link function was slightly less than Stukel’s score test ''  Can I conclude from this which test has more power or that Hosmer–Lemeshow has less power (to detect these specific anomalies) ?  Second remark  The paper by Hosmer et. al. that I referred to supra, compute (simulate) the power to detect specific anomalies (the power can only be computed if an $H_1$ is specified).  This does at my opinion not imply that these results can be generalised to ''all possible alternatives $H_1$'' ?


I tried to install xdman using   sudo add-apt-repository ppa:noobslab/apps  sudo apt-get update sudo apt-get install xdman   but I can't download it; I get this:   E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?   I get the same error if I try to install anything else.  After resolving that, I now get the error  E: unable to locate package xdman


How to flip X and Y axes in Excel scatter chart with more than one series

I don't understand how to perform a simple 90 degree axis manipulation in Excel.  Here is my data:  ╔════╦══════╦═══════╗ ║ Y  ║  X1  ║  X2   ║ ╠════╬══════╬═══════╣ ║  1 ║ 0.00 ║ -1.00 ║ ║  2 ║ 0.50 ║ 0.00  ║ ║  3 ║ 0.67 ║ 0.33  ║ ║  4 ║ 0.75 ║ 0.50  ║ ║  5 ║ 0.80 ║ 0.60  ║ ║  6 ║ 0.83 ║ 0.67  ║ ║  7 ║ 0.86 ║ 0.71  ║ ║  8 ║ 0.88 ║ 0.75  ║ ║  9 ║ 0.89 ║ 0.78  ║ ║ 10 ║ 0.90 ║ 0.80  ║ ╚════╩══════╩═══════╝   And here is what the default scatter looks like:    Excel has correctly picked up my two series (X1 and X2) but I want to flip the X and Y axes. The result should look like this:    I had to create that by manually editing the X and Y values for each series within Excel's Select Data... dialogue. That's fine for one or two series, but what if I want to plot 100s of series? I can't possibly reconfigure them all manually. So how do I format my data so that Excel treats the first col as Y values, and each subsequent col as the corresponding X value of each new series? Thanks


Subscription Bug: Emails including jobs that do not match defined filters

A few days ago, many users have started receiving emails from job subscriptions that contain jobs that do not match the filters defined for the subscription.  The examples below show screen-grabs from a couple of emails where is bug has manifested itself.  The first shows a subscription for jobs that allow remote working:   When you look at any of the jobs from the above email, they do not allow remote working:   The second example shows jobs confined to a specific geographic area, however, the jobs included within the email are clearly outside of the geographic area defined:   Furthermore, performing a search on the Stack Overflow Careers site for C# jobs within 50 miles of London, UK also give erroneous results:   It seems that there's a bug with the job search that's ignoring all search criteria.


I am not getting the motivation behind defining Complex plane. I mean why defining such plane helps to understand $i$? So if I want, can I replace any other number in place of $i$( suppose, I replace it by $\Phi=\frac{\sqrt{5}-1}{2})$ to study properties of some number? Will that be helpful? If yes, why?   I have searched for this question, it is not asked before here. A similar question - . But that is defferent from my question.


iterating an interable sequence in reverse order

I have a iterable sequence nums = [1,2,3,4]. I want to create a generator function which, when next(nums) is used, will return the values one by one in reverse order. My goal is to do this using len(). I know the length of the list minus one would be the index of the last item in the list. How would I write the code for the output using len():      next(nums) 4     next(nums) 3     next(nums) 2     next(nums) 1   EDIT: Forgot to mention no other built-in functions are allowed.


Making the child finish their food even if they are already full

As a child, my parents always made me finish my food even if I was already full. Food definitely isn't wasted this way, but overeating is not good either.  What would be the advantages and disadvantages of making/forcing a child to finish their food even if they are already full?   For the sake of this question, disregard the child's food preference (i.e. he doesn't not finish his food just because he doesn't like the food)


I would like to write something of the sort. It's a form of an accent but I do not know how to write letters instead of just dots or a tilde.  Thank you


I am trying to setup my server so that I can restart Apache as userx without having to enter a sudo password.  However when I logon as userx and run sudo /usr/sbin/service apache2 restart it asks me for a password.  What have I got wrong?  Below is the content of my sudoers file.  # # This file MUST be edited with the 'visudo' command as root. # # Please consider adding local content in /etc/sudoers.d/ instead of # directly modifying this file. # # See the man page for details on how to write a sudoers file. # Defaults        env_reset Defaults        secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"  # Host alias specification  # User alias specification userx ALL=(root) NOPASSWD: /usr/sbin/service apache2 restart  # Cmnd alias specification  # User privilege specification root    ALL=(ALL:ALL) ALL  # Members of the admin group may gain root privileges %admin ALL=(ALL) ALL  # Allow members of group sudo to execute any command %sudo   ALL=(ALL:ALL) ALL  # See sudoers(5) for more information on "#include" directives:  #includedir /etc/sudoers.d   Let me add back in my edit where I point out what the answer was and explain where I found the solution in case other people stubmle across this.  Turns out that userx was a member of the admin group and the %admin group entry was overwriting the settings. Moving the userx line below the %admin line solved the problem.  This answer also helped


Keep getting java.lang.NullPointerException when trying to read from JSON file

I'm trying to read from a json file in order to create visual images via processing. My code so far is:  public void generateShape(JSONObject file) {     //convert file to json object     JSONArray shapes = (JSONArray) file.get("shapes");     for (Object o : shapes) {         JSONObject json_shape = (JSONObject)o;         //getting shape id and function so we know which shapes to create         id = ((Number) json_shape.get("id")).intValue();         func = ((Number) json_shape.get("func")).intValue();         animate = ((Number) json_shape.get("animate")).intValue();         stroke_weight = ((Number) json_shape.get("stroke_weight")).floatValue();          JSONArray strokes = (JSONArray) json_shape.get("stroke");         Iterator<Float> iterator = strokes.iterator();         index = 0;         while(iterator.hasNext())         {             stroke[index] = ((Number)iterator.next()).floatValue();             index++;          }   stoke[] is an array of floats which will control the colour of the stroke. The json file im parsing from is   {    "shapes": [ {   "id":0,   "func":1,   "stroke":[143,50,200],   "stroke_weight": 70,   "animate": 1,   "jelly_func": 5,   "points":[268,330,400,333,74,210,90,300]    }    ] }   im getting the error at the line:       stroke[index] = ((Number)iterator.next()).floatValue();   I'm using the json.simple library and all solutions i've seen are for org.json library  I could hard code the values in the stroke array but I wanted to try iteration instead. Any tips/guidance?  full stack trace is  java.lang.NullPointerException at ImageLoader.generateShape(ImageLoader.java:35) at Sketch.setup(Sketch.java:48) at processing.core.PApplet.handleDraw(PApplet.java:2404) at processing.awt.PSurfaceAWT$12.callDraw(PSurfaceAWT.java:1557) at processing.core.PSurfaceNone$AnimationThread.run(PSurfaceNone.java:313)   where sketch is:   ImageLoader image = new ImageLoader();     JSONParser parser = new JSONParser();     try {         JSONObject file = (JSONObject) parser.parse((new FileReader("save_data.json")));         image.generateShape(file);      }     catch (FileNotFoundException e)     {         e.printStackTrace();     }     catch (Exception e)     {         e.printStackTrace();     }   eta: ok so upon removing the line causing the exception, and checking if my json values are even being read I can confirm the values being parsed are correct when I print them to console. I just now need to put them in an array


Generate "using" directive from fully-qualified class name without having to go to the top of the code file in Visual Studio 2017

Is there a shortcut for adding a using directive without having to leave the point where I'm working in the code to scroll up to the top of the file?  For instance, if I don't have using System.IO; and I add string fullPath = System.IO.Path.Combine(path1, path2); to a method where I'm working, I'd like to be able to right-click or something to get the option to add using System.IO; at the top and remove it from the beginning of System.IO.Path.Combine.  I'm know third-party tools like Re-Sharper can enable this, but I thought this would be a simple feature that would be present by VS 2017.


Sum $\frac{1}{6} + \frac{5}{6\cdot 12} + \frac{5\cdot 8}{6\cdot 12\cdot 18} + \frac{5\cdot 8\cdot 11}{6\cdot 12\cdot 18\cdot 24}+\ldots$

A series is given as follows   $$\frac{1}{6} + \frac{5}{6\cdot 12} + \frac{5\cdot 8}{6\cdot 12\cdot 18} + \frac{5\cdot 8\cdot 11}{6\cdot 12\cdot 18\cdot 24}+\ldots$$  Can you give me hints to get started finding its value? Thanks.


Questions in titles need to be repeated, why?  To me this pattern seems ridiculous. But I frequently encounter the "not a real question" situation, when I put my question in the title, then the context for that specific question in the 'question body'.     So:  I am to take it that the title is almost completely irrelevant for establishing subsequent question body is asking? I choose my titles to expose the actual question so it need not be repeated below. If questions need to be repeated in the body, could we simply title it "A question, click here and read below" ?   Tagged bug, as I have found this "problem" to be quite reproducible.  Steps to reproduce:   Ask a question with the clear, simple question in the title, and the evidence/context/example in the question body. Await close votes.


Okay, I apologize if there are similar threads... but I've scoured the internet and never have I run across a helpful answer. So I'll ask here...   I have an old laptop, an Acer Aspire 5515... It was running Vista and was taking 5-10 seconds to just do anything, even as simple as opening a folder. So I decided to install a windows-user-friendly version of Linux - something I've wanted to try for a long time. I ended up settling on Kubuntu because I read somewhere that it's medium-light weight, and good for people used to running windows, after all, I can always replace it with something different later on.   I went to the ubuntu site itself and downloaded  "kubuntu-16.04.1-desktop-am64"  Then the problems started flowing in. Some of it user error I admit... first the CD I got wasn't big enough, then I forgot you can't copy past an iso file, then I couldn't get the Acer to boot from cd drive  Eventually, I fixed these... I burnt the iso image right, used a larger DVD, and changed the bios to boot from the cd. I went to try to just 'try' Kubuntu but that just wasn't working very well, so I just went and tried to go ahead and replace the OS. I knew it would kill everything on the Vista, but I already transferred the files I wanted to keep and the computer was unusable as it was, so I figured why not.   I went through with trying to do the installation, and the first time got to about 80% when I got the Errno 5 Input/Output Error  Alright then... it said something about heat so I placed the computer on a low running box fan as a make shift computer fan (It was getting hot anyway), and I tried again. Made it to about the mid-60s and got the same error.   This time, I went and I double checked the iso... it's indeed the most recent one on the Ubuntu site, and then I used winMd5sum, which says the checksum is correct. I then got another disk and downloaded imgBurn and burnt a new disk at the lowest possible speed (tried for 1x, but it did 2x).   Tried again and it still pulled the same error around the same spot.  So this time at the bootup screen I pressed shift and chose Check for Defects, it returned with Errors found in 1 file  The memtest86 says no errors.  So I'm assuming that means there's a problem with the CD/iso? The check sum was supposedly correct and it was burnt on the lowest possible burn with trusted software. Also, the cd drive works just fine and the disk itself is brand new without a scuff on it.  I'm pretty stumped what to do. I'm going to try to find a cheap flash drive at the dollar store or something to try to boot from USB, but if there is any troubleshooting I could do to get this to work without having to spend money I can't really afford, that'd be really helpful.   As it stands I have a nearly 10-year-old computer with no OS whatsoever on it because the windows section is all deleted, but the Ubuntu section is not fully installed.


A white light, as we all know, is composed of seven lights VIBGYOR. Each of the component lights has distinct frequency ranging from one value to another. So, when the photons have wavelength of 600 nm it becomes a yellow light and when it changes to 700 nm it becomes a red light. So, does this imply that the frequency with which a group of photons vibrate determine the colour of light? Well, in that case, with what frequencies are photons vibrating for a white light?


Can a Druid pull a target through other creatures with Thorn Whip?

What blocks the "pull" from Thorn Whip?  Thorn Whip:  ...and if the creature is Large or smaller, you pull the creature up to 10 feet closer to you.  As a specific example, the druid pulls a creature that is 15 feet away, but right in front of the target (and between the target and the druid) is another creature.  Can the target be pulled through the other creature?  Does it matter if the other creature is an enemy or ally?  Does the other creature have any choice in the matter?


Whenever I try to install Atom through Ubuntu Software, it fails!

I want to install Atom, which I can do by clicking the 'install' button on 'Ubuntu Software' application. However, every time I click it, so as to install Atom, if fails. Below is a screenshoot of the error that I get. But I don't know what this status code means and how I can fix it: 'snapd returned status code 400: Bad Request' !    George Thornton


Why are my iMessages showing as coming from my email address when I've set my Caller ID to my phone number?

When iOS 5 first came out, I added my @me address to my iPhone and iPad. People could iMessage me at my email address, and I'd see it on both devices. This wasn't always perfect, and recently I decided to forgo this, and just use my phone number on my phone and email address on the iPad.  So, I switched the caller ID on my phone to the phone number again, deleted all my text message threads that were created when I was using the email address, and started a new thread. Somebody who didn't have my email address saved in their contact asked why my text messages were coming from an email address, and another reception confirmed that when he tapped 'Contact Info' at the top of the message thread, my email address was highlight in blue, NOT my phone number - indicated that this is where the message was coming from.  Does anybody know why this is happening? Is there another setting I need to change? I'd really prefer to not have them come from my email address, because then any replies will goto both my phone and my iPad - which I don't want.


I know I must have toggled something but for the life of me I can't figure it out. In this one Blender file any time I make a curve and go into Edit mode I cannot adjust the handles of the curve. The handles are there but whatever point I click on(be it vertex or handle) and try to move it, the whole curve moves. However if I open up a different or new project the curve handles work just fine and I can change the shape of the curve with ease. I can't seem to find the solution anywhere. If someone could help be I would truly appreciate it.


Software center installation stuck after script cancellation

Attempted to add the Matlab installation and it asked me where my current installation was -- never have tried to install it before -- I hit cancel when it asked for the installation directory and now Ububtu Software Center bogs down the machine and everything in line to download and install behind it in the queue is hosed.    No places to hit pause or cancel for any of the line items. Just says "Applying Updates" and is in the list no matter what (I already closed out USC and restarted the machine several times).     How should I proceed to get this out of the way? Is it an USC specific problem or an installation script problem?    TIA  @dobey:    I do not have matlab installed -- I was shopping on the USC, saw the matlab icon, tried to download the package.     "Bogs down the machine" as in USC pulls 22% usage all by itself and the rest of the system suffers.    The package is in limbo because it does not show as installed nor in history, so how do I kill the package from my USC download list?  @Daniel Llewellyn  Both commands say the same thing at the end:   1 not fully installed or removed  debconf: DbDriver "config"  /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable  dpkg: error processing man-DB (--configure): sun process installed post-installation script returned error exit status 1  No apport report written because MaxRrports is reached already   Errors were encountered while processing:  man-db   E: Sub-process /usr/bin/dpkg returned an error code (1)


Simple android code, not sure what's wrong

This is a simple password app, and it's not really working, i'm not sure what most of this sentences mean. I have some knowledge in c++ but this is new to me. Can somebody correct me? I can't find a site that explains this well.          public void addListenerOnButton(){      geslo = (EditText) findViewById(R.id.password);     Gumb  = (Button) findViewById(R.id.Gump);      Gumb.setOnClickListener(new View.OnClickListener() {         @Override         public void onClick(View view) {         String text="banana";         if(geslo.toString()==text){             Intent newactivity= new Intent(MyActivity.this,MainDatoteka.class);             startActivity(newactivity);         }         }     }); }


single word: person who loves the night or staying up at night

What a person would be called who loves the night or staying up at night?   In both senses, like the young generation with their smartphones, and someone who just loves staying up late at night.


Sensor hangs loose in the body when camera is switched off

I own a Panasonic DMC-G81 (same as G80/G85) with in-body Image Stabilization.  When turned on everything is just fine, but when turned off, the sensor is wobbling around in the body. When no lens attached, it's clearly visible moving about 1/2 cm in the body. I didn't find anything about it in the internet. Shouldn't the sensor be in a kind of parking position, should I worry about the sensor ?  I'm not sure if that is the usual behavior, maybe someone with the same or similar body can have a look.


Connected to wifi, but no internet access

first question here. I was using wifi normally on my phone. Then I turned it off and after some time turned it back again. Since then I can not access the internet. It's showing Connected(no internet access).  I tried to set the IP static. It did not work for DNS 192.168.200.1. No matter what IP I set with this DNS it does not work. Then used the 8.8.8.8 as DNS, now it's connected. But it is really slow, and the connection does not seem stable. Every time I have to reload google.com several times just to get the page.  The problem is specific to this device only. Other devices connected to the same network are perfect.  Can someone suggest me what should I do? Is this a router issue? Or is this my device problem?  I'm new in this area. So my knowledge is not so deep and you might have to explain things a bit more in detail for me to grasp the concept.


Mathematical symbol not supported in php

I have a some text saved in a MySql database that contains a mathematical symbol. When I read this from php code it become something like this α=? and β=?  Text in database:
A round balloon of radius r subtends an angle α at the eye of the observer, while the angle of elevation of the centre is β. The height of the centre of balloon is
   Text read from php:
A round balloon of radius r subtends an angle ? at the eye of the observer, while the angle of elevation of the centre is ?. The height of the centre of balloon is
   How to solve this problem?


I've two problems:  I took my old HDD and put it in a hard-drive enclosure. Then I connected this to an notebook which is running on Windows Vista. I also connected a USB stick with Ubuntu 14.04 with the notebook. Next step was to install Ubuntu on the external HDD. After the installation I had to make a restart to start with Ubuntu. I turned off the notebook and changed the BIOS to boot on the external HDD. I turned it on and. Nothing happened. Okay, I decided to boot the internal HDD from the notebook. Then a purple window from Ubuntu appeared asking if I wanna start Ubuntu or Windows Vista. I choose Ubuntu and it worked. After that I did the same and chose Windows. It worked as well. BUT now I can't boot the internal HDD without having the external HDD connected to the notebook. It says something like error grub rescue. That is problem one.    Problem two is that I wanna use my HDD in the hard-drive enclosure also without this notebook. I wanna connect it to other computers. What can I do?


Why can't I make a symbolic link (mklink) even when I'm an administrator

When I run mklink /D "C:\Users\bwilliams\AppData\Roaming\Sublime Text 2" "C:\Users\bwilliams\Dropbox\Sublime Text", I get this error `You do not have sufficient privilege to perform this operation.  Why not? I'm administrator, and just want to create a link in my own Users\bwilliams directory to another folder in my Users\bwilliams directory?  What am I doing wrong here?  Thanks.


"learn more" link beside tag name when modifying a question's tags does nothing in the latest version of Chrome

This was a  issue when raised previously through Chrome v30 Dev: , however now that Chrome v30 is no longer in dev/beta the issue is still present:    In the latest version of Chrome, if you click on this link the tag suggestions divider will close but nothing else will happen.  The link itself points to the tag wiki for the highlighted tag:  learn more   If you give the tag suggestion area focus, however, the link then works as it should.


Where did the Iron Man suits come from in Age of Ultron?

At the end of Iron Man 3, all of the Iron Man suits are destroyed with the very strong indicator that they will not be re-done — rather, Tony Stark will go it alone without the suits.  However, in Age of Ultron, there are clearly Iron Man suits. Where did they come from? What changed? Or am I just getting the timeline wrong?


HP LaserJet 1018 doesn't work under ubuntu 15.04

I have Ubuntu 15.04 and an HP LaserJet 1018 connected by USB. Ubuntu has found drivers and shows that everything is OK. When I send test page to printer it shows that it was handled first and than operation completed but nothing actually happens.  Can somebody help me? I'm new in using Ubuntu. Maybe I do something wrong...


how to prevent sql injection by using escape string or other method?? i do have some codes, but i not sure how to do? any help?  <?php                             if (isset($_POST['submit'])){                             session_start();                             $username = $_POST['username'];                             $password = $_POST['password'];                             $query = "SELECT * FROM users WHERE username='$username' AND password='$password'";                             $result = mysql_query($query)or die(mysql_error());                             $num_row = mysql_num_rows($result);                                 $row=mysql_fetch_array($result);                                 if( $num_row > 0 ) {                                     header('location:dashboard.php');                             $_SESSION['id']=$row['user_id'];                                 }                                 else{ ?>
Access Denied
                                  <?php                             }}                             ?>


USB-C Chargers: Is it safe to charge a phone with a laptop's power supply?

I have an HP Chromebook and a Nexus 6P smartphone, and both of them use USB-C connections for charging.  When I plug the Chromebook into the Nexus's charging cable, it works fine and I just get a message that says I am connected to a "low-power charger".  However, is it safe to plug the cell phone into the laptop's power supply?  I'm afraid that doing so might fry the phone.


On the proof of existence and uniqueness of radix representation

Base-b Representation of an Integer: Why can I make the assumption about number of terms in expansions in uniqueness part?   Reading the book of Koshy I have come across the below theorem. It states that I can write any integer $N$ in a base $b\ge2$ representation $N=a_kb^k+...+a_1b+a_0$ such that $0\le a_i<b$, $a_k \neq 0$ for some $k\ge0$.  In the uniqueness part, why can I assume the expansions contains the same number of terms ? I must prove that all expansions of $N$ equal the one in the theorem, but if I add terms to the expansion by zero coefficients, well, then the expansion is not in the proper form anymore ? (the greatest term in the expansion is $0$ if I add zero coefficients) .  Can someone help clear this out ?     Why can I assume the expansions contain the same number of terms ? If I add terms to the expansion, well then I've violated the form of the expansion ?


Holomorphic function $f:B(0,1) \to B(1,4)$ with $f(0)=3$ and $f(\frac{1}{2})=1$

Problem  Find all holomorphic functions $f:B(0,1) \to B(1,4)$ that verify $f(0)=3$ and $f(\frac{1}{2})=1$.  I have no idea how to attack this problem,since it comes after an exercise related to Schwarz lemma, I thought that maybe the idea is to somehow apply the lemma in this problem as well, but if that is the case, I don't know how could I use it. I would appreciate suggestions.


When you are inside some non uniformly and non radially polarized sphere, why do the dipoles from outer shells don't affect you (the potential there is only due to inner dipoles from what I have seen)?


How can I check if a class has operator<< defined for it?

How can I check if std::cout << myClass; is valid? I'd like to do something like:  class Logger {  public:   // Some kind of enable_if(operator<< doesn't exist)   void printMyClass(MyClass& my_class) {     std::cout << "Got a myclass" << std::endl;   }       // Some kind of enable_if(operator<< exists)   void printMyClass(MyClass& my_class) {     std::cout << "Got a myclass: " << my_class << std::endl;   }     };


What is `^M` and how do I get rid of it?

When I open the file in Vim, I see strange ^M characters.  Unfortunately, the world's favorite search engine does not do well with special characters in queries, so I'm asking here:   What is this ^M character? How could it have got there? How do I get rid of it?


A textbook I'm self-studying - Introduction to Mathematical Statistics by Hogg - has the following text:  T(a) = $\int_{0}^{\infty} y^{\alpha-1}e^{-y} dy$ [gamma function] If $\alpha > 1$, an integration by parts shows that $T(\alpha) = (\alpha - 1)\int_{0}^{\infty} y^{\alpha-2}e^{-y} dy$.  I'm having trouble deriving this for myself.  How does an Integration by Parts lead to this result? Thank you.


Why do I get an "Undefined reference error" when implementing a singleton class?

I'am trying to implement a method that returns me an instance of the class, but it's is crashing when it tries to create the instance at the first time. I don't know how to implement the singleton in C++/QT  Main  #include <QCoreApplication> #include "carro.h"  int main(int argc, char *argv[]) {     QCoreApplication a(argc, argv);      Carta* nueva;     nueva->getInstance();     nueva->setColor("rojo");     cout << nueva->getColor() << endl;      return a.exec(); }   Carro.h  #ifndef CARRO_H #define CARRO_H  #include <string> #include <iostream>  using namespace std;  class Carta{  private:     string cara; //valor     string palo; //simbolo     string color;     string direccion;      static Carta* m_instance;  public:     //constructor     Carta(){     }     static Carta* getInstance(){        if(!m_instance){            m_instance = new Carta;        }        return m_instance;     }      string getDireccion(){         return direccion;     }      void setColor(string pcolor){         color = pcolor;     }      string getColor(){         return this->color;     }      string getPalo(){         return this->palo;     }      string getCara(){         return this->cara;     }      //print     string print(){         return (cara + " de " + palo + " Color: "+color);     }     };  #endif // CARRO_H


If I select a single vertex and drag, the whole object stretches out instead of just the vertex selected

I subdivided the cube and changed to edit mode so I can edit the vertex. The problem is if I select a single vertex and drag, the whole object stretches out instead of just the vertex selected. The proportional editing if off, so I don't know what is wrong cause I am new to blender.


We have a job that is set to run Monday thru Friday. Up until two weeks ago, it ran fine 5 days a week. For the last two weeks it has failed on Monday. I am unable to locate where to find the point of failure.   ### Example Scripts 0 2 * * 1-5 /admin/scripts/example.exp 1>/dev/null 2>&1   We run AIX 7.1.  I've looked in the /var/log/ and there is no cron file there. Looking for advice to add to this so we can troubleshoot.   I found that the log is located in /var/adm/log. Further we are getting this error repeatedly ever since this date/time. How do I clear this max limit?  c queue max run limit reached Fri Nov 25 21:52:00 2016 ! rescheduling a cron job Fri Nov 25 21:52:00 2016


How should off-topic questions be flagged when no off-topic reason from the dialog applies?

Currently, when flagging an off-topic question, the following choices are offered.   Questions about general computing hardware and software are off-topic for Stack Overflow. Questions concerning problems with code you've written must describe the specific problem and include valid code to reproduce it. Questions must demonstrate a minimal understanding of the problem being solved. Questions on professional server, networking, or related infrastructure administration are off-topic for Stack Overflow unless they directly involve programming or programming tools. Questions asking us to recommend a tool, library or favorite off-site resource are off-topic for Stack Overflow as they tend to attract opinionated answers and spam. This question belongs on another site in the Stack Exchange network   However, there are some questions that fit in none of these categories.  For example, career advice questions are off-topic here (and on programmers.SE), questions like  are off-topic on pretty much any SE site.    Some questions might also be relevant on another SE site not listed when the "belongs on another site" option is selected.  How should those questions be flagged?  Why isn't there a "it's off-topic because it is" option?  EDIT: just to be clear, I don't have the "Other" option under Off-Topic.


Consider the following code:  \documentclass{article} \usepackage{booktabs,pgf} \begin{document} \pgfmathsetlengthmacro{\ratio}{\the\textwidth/4}  \hrulefill \\  \begin{tabular}{@{}llll@{}}   \toprule   \makebox[\ratio][l]{xx}&\makebox[\ratio][l]{1} &\makebox[\ratio][l]{2}&\makebox[\ratio][l]{3}\\   \makebox[\ratio][l]{xx}&\makebox[\ratio][l]{1} &\makebox[\ratio][l]{2}&\makebox[\ratio][l]{3}\\   \bottomrule \end{tabular} \end{document}   with output    How can I determine \ratio such that the table fills (exactly) the textwidth of the page? As seen, currently the \ratio is too large such that the table becomes wider than the text width.


I have a doubt on this theorem:     The probability integral transform states that if ${\displaystyle X}$ is a continuous random variable with cumulative distribution function ${\displaystyle F_{X}}$, then the random variable ${\displaystyle Y=F_{X}(X)}$  has a uniform distribution on $[0, 1]$.   The theorem is longer, but I don't understand this first part. If I have a continuous $F(X)$ and I set $Y=F(X)$, then this implies that $Y\sim U(0,1)$? Why?  Thanks!


Redirect domain to specific URL on other domain

I have got apache2 server with one virtual host. It is typo3 CMS. There are multiple pages:  foo.com -- DNS A record --> 32.32.32.32   |_ foo.com/bar/   |_ foo.com/baz/   Now I want to configure other domain (qux.com, also with A record to IP same as below) to redirect it to foo.com/baz/, for example when user put qux.com in browser I want him to see qux.com in address bar and foo.com/baz/ webpage. In order to do this I have put this configuration to file in sites-enabled:  RewriteEngine On RewriteCond %{HTTP_HOST} ^qux.com RewriteRule ^(.*) http://foo.com/baz/ [P]   but it has no effect. What is a cause? How to configure it properly?  Edit: here is my vhost config:  <VirtualHost *:80>         ServerName foo.com         ServerAlias *.foo.com         ServerAlias qux.com         RewriteEngine On         RewriteCond %{HTTP_HOST} ^qux.com         RewriteRule ^(.*) http://foo.com/baz/ [P]         DocumentRoot /var/builds/stage         <Directory /var/builds/stage>                 Options Indexes FollowSymLinks MultiViews                 AllowOverride all                 Order allow,deny                 allow from all         </Directory> </VirtualHost>


Strange error (?) when I run `man` command from a folder that no longer exists

Let's have a look at the followings:  radu@Radu:~$ mkdir test radu@Radu:~$ cd test radu@Radu:~/test$ rmdir ~/test radu@Radu:~/test$ man ls man: can't change directory to '': No such file or directory  Normally, I would say that the last line from the previous output from my terminal is an error. But how can I understand it? And why does this appear only in the case of man command (as far as I know; even pwd or ls does not have any problem)?  Furthermore, let's see again:  radu@Radu:~/test$ man ls man: can't change directory to '': No such file or directory radu@Radu:~/test$ echo $? 0  What? It was a success (see the output of man man |& grep -A 1 '^EXIT STATUS$')?  Another version of man  When attempted with another version of man the same thing works.  $ mkdir mantst $ cd mantst/ $ man ls            <--- works $ rmdir ../mantst/ $ man ls            <--- works $ man --version man 2.6.3


Is $\mathbb{R} \backslash \mathbb{Q}$ a $F_{\delta}$ set?

Recall that an $F_{\sigma}$ set is, by definition, a countable union of closed sets.  We see that $\mathbb{Q}$ is an $F_{\sigma}$ set: $\mathbb{Q} = \cup_{q \in \mathbb{Q}} \{q\}$.  Is $\mathbb{R} \backslash \mathbb{Q}$ an $F_{\sigma}$ set? Note: $\mathbb{Q}$ and anything in $\mathbb{R} \backslash \mathbb{Q}$ are hollow.  I have no idea how to do this.  I know the goal is to use Baire Caegory Theorem.  I think that since anything in $\mathbb{R} \backslash \mathbb{Q}$ is hollow, we have that $\mathbb{R} \backslash \mathbb{Q}$ is a collection of hollow sets, $\{F_n\}$ in $\mathbb{R}$. I don't know how to show the sets are closed or the collection is countable.  Then by Baire Category Theorem, we know that $\cup_{n=1}^{\infty}$ is hollow, but $\mathbb{Q}$ being hollow means $\mathbb{R} \backslash \mathbb{Q}$ is dense  $\mathbb{Q}$ is hollow, that tells us that $\mathbb{R} \backslash \mathbb{Q}$ is dense (which seems to contradict the note, but maybe I'm just not reading it right).   If this isn't the best way to approach the problem, please let me know the better alternative.  EDIT: I think it might be best to prove it as such: Suppose $\mathbb{R} \backslash \mathbb{Q}$ is a $F_{\sigma}$ set.  Then $\mathbb{R} \backslash \mathbb{Q} \cup \mathbb{Q}$ is a countable collection of closed collow sets so by Baire Categoty Theorem, the union of this collection of sets is hollow, but $\mathbb{R} \backslash \mathbb{Q} \cup \mathbb{Q}$ is just $mathbb{R}$, which we know is dense, so we've reached a contradiction


I basically have 2 questions about local TLD vs .com.  First question: There already exists a website "keyword.nl" with a crappy website, no SEO optimisation. Is it possible for a website "keyword.com" to rank higher than the "keyword.nl" website on "google.nl" when searching for "keyword"? Or will it always display the .nl website higher because it's a local TLD and the URL consists entirely and only from the searched keyword and it's searched on the .nl version of google?  Second question: I know it's good for SEO to have many websites link to your website. But I also read that local TLD's will score higher on that specific google TLD (.fr website will rank higher in google.fr, etc.) With both those facts in mind, is it better to create a "keyword.com/fr/" and "keyword.com/nl/" website or a "keyword.fr" and a "keyword.nl" website? (In other words, .com/langauge for more links to the website, or a "keyword.local-TLD" website for every different language version of the website) Or maybe even a subdomain? ("fr.keyword.com?")  Kinda new to this, so thanks in advance!  --Edit: additional info--  The reason that I phrased the original question like this is because I wanted to keep the question strictly "webmaster-side". However I feel like maybe I should clarify the background of this question more thoroughly, so the question becomes more clear, and thus the answer. But I don't know if this would make the question a more legal one instead of a "webmaster" one, so please correct me if this is the wrong place to post this question.  I'm a student working on websites in my sparetime, I have basic knowledge about SEO, but that was all local, for companies operating only in one country. However this time a friend contacted me who wants to found a company called "X" (e.g). He wants to ship/operate to multiple countries, but he will first found it (and he himself) lives in The Netherlands (.nl). However there already exists a company in The Netherlands called "x" with the website "x.nl". As far as I understood, the fact that both the companies are called "x" doesn't matter, in trademark/company registery terms, since they are both operating in different work sectors.    But the main issue here is, could my friends website "x.com/nl" outrank the "x.nl" on "google.nl" if you only search on the brand name; "x"?  @Closetnoc:  Hi, thanks a lot for your answer, it gave me some clarification however I feel you misunderstood my first question because of my use of "keyword.com" as an example URL. So I don't really know what conclussion I should draw from your first answer. I updated my question with additional info to clarify it more broadly. From your second answer this is what I understand: A .nl URL will not do that great on google.com, however a .com URL can do just as well as a .nl search on google.nl? So considering the info above, it's best to go with a x.com/fr and a x.com/nl URL, right? Please correct me if I misunderstood. However, if so, that still leaves the first question, if a "x.nl" is already taken, could a "x.com/nl" still outrank it at "google.nl"?


Problems with my sitemap.txt in Google Search Console for indexing PDFs

Here is the contents of my sitemap.txt http://www.merrittnet.org/Papers/ http://www.merrittnet.org/Marmot/  in these 2 directories are around 50 PDF files it has been around 5 days now and when I search using https://cse.google.com/cse?cx=acf88dbf364fe0f82  (search words like "water" or "hydrology" should return some hits but dont or FileType:pdf) Is there some special configuration that needs to be done for a folder of PDFs also to note in these directories I have an index.php that dynamically creates href links for all.pdf files in that directory.


Even function has even sequences of polynomials converging uniformly?

If $f$ is an even continuous function on $R$ and ($p_n$) is a sequence converging to $f$ uniformly on $R$ then ($p_n$) is even for each $n$. Intuitively I think this is true but I'm not sure how to prove it.


Suppose $g$ is infinitely differentiable function such that for all natural $n$, there exists $c_n$ and $\delta_n$ such that if $|x|<\delta_n$, then $|g(x)|\leq c_n|x|^n$. Show  $g^{(n)}(0)=0$ for all $n$.  Could someone provide a hint on where to start? I was thinking of a proof by induction, but even the base case eludes me.


Is it possible to convert LVM filesystem back to normal?

My filesystem setup is an LVM setup.  I'm wanting to try installing ElementaryOS Luna Beta 1 on its own partition, but unfortunately it doesn't support LVM yet.  Is there any easy way to do this?


I have an error in my Drupal 7 site when I try to install any module.   If I try the Install from a URL I get:     HTTP error 0 occurred when trying to fetch .      Unable to retrieve Drupal project from .   If I try Upload a module or theme archive to install I get:     An AJAX HTTP request terminated abnormally. Debugging information follows. Path: StatusText: ResponseText: ReadyState: 4   The error page shows me:     Notice: Undefined index: log in update_authorize_install_batch_finished() (line 235 of V:\www\site\modules\update\update.authorize.inc).   Warning: Invalid argument supplied for foreach() in update_authorize_install_batch_finished() (line 235 of V:\www\site\modules\update\update.authorize.inc).   Notice: Undefined index: log in update_authorize_install_batch_finished() (line 276 of V:\www\site\modules\update\update.authorize.inc).   Notice: Undefined index: tasks in update_authorize_install_batch_finished() (line 277 of V:\www\site\modules\update\update.authorize.inc).   Installation failed! See the log below for more information.   Any ideas on how I can troubleshoot this?


NameError: name 'Correct' is not defined

I am trying to check if the user typed in the correct password if they did then I want to make a bool true but for some reason it's just declaring a new bool with the same name I have tried looking for other questions but none of them are in my situation  Correct = False  def SubmitPassword():         if e6.get() == password:                 Correct = True```


To show that  $\frac{d}{dx}:A \to L^2 (a,b)  $ is not continuous, where $$A=\left\{u \in L^2 (a,b): \frac{du}{dx} \in  L^2 (a,b) \right\} $$  I'm trying take a map's sussection that $|du_n|>c_n|u_n|$ but I cant find.


Dublin transit visa requirements for Indian citizens

My wife was not allowed to board her flight from Bangalore to the UK via Frankfurt and Dusseldorf as the Lufthansa staff claimed she needed a Shengen visa to take the flight from Frankfurt to Dusseldorf. She has an Indian passport with a valid UK spouse visa for 2 years.   I'm currently trying to book her on another flight and I've seen one going from Bangalore to Manchester,UK via Abu Dhabi and Dublin. I'm worried that the same issue may come up again in Dublin. Would she require a transit visa in this scenario to enter Dublin?  Also were the Lufthansa staff correct in not letting her board the original flight. I'm sure I've read that spouses of British Citizens are amongst those exempt from airport transit visa requirements in Germany?


Consider the following game.      P has a fair $6$ sided die and continuously rolls it while keeping   track of the sum, $S$, of the top faces. P can bail anytime and leave   with $S$ number of dollars. However, if $S$ is ever a perfect square,   the game ends and $P$ gets nothing.   When is it most profitable for $P$ to quit? What is the expected amount of money does $P$ make when $P$ quits at this optimal time?  I ran sum simulations of this and found that on average, the game runs for $8$ rolls and the expected earnings of $P$ is around $28$ dollars. Can we prove this?  The distribution of earnings with $8$ rolls is shown below.


I have known a theorem from the link   The theorem is that a polynomial of odd degree has a root.But I don't know its proof.Can anyone prove it with intuition.


Does $\sum \frac{n!e^n}{n^n}$ converge or diverge

I have tried root and ratio test but they were inconclusive. thank you very much


Opacity Mask With Multiple Images (Illustrator CS5)

I am trying to do an opacity mask and it is driving me crazy.  Bascially I have a layer of ice. It's four different pictures of ice overlapping each other so it looks like a whole bunch of ice. I want to have it fade in from both sides (left and right) until it is completely opaque in the middle.  I've select all of the pictures and chosen 'Make Opacity Mask' from the Transparency Panel and it disappears but then I don't know how to manipulate the opacity.   In the Transparency panel it doesn't show a picture of what I'm working with so I can't simply click next to it to create the opacity mask like I've seen in tutorials.  I've also tried to overlay a rectangle over the objects, choose them all then try 'Make Opacity Mask' but that didn't work either. Any ideas? Thanks.


so I am a beginner with Python and face one problem. The problem is that I have the following dict:  topperformer1 = {"Olivia":19, "Maria":18, "Pedro":15, "Nuno":17, "Julia":19, "Vasco":17, "Carla":18}   Now I would like to print the 3 highest grades (value), but if I sort the dict after the value and print it, I only get the value with no key.  I hope you can help me and best regards


Installing applications from USB drive to Ubuntu 18.04

Currently I have Ubuntu 18.04 LTS Bionic set up but no internet. So I can't install/download applications. What would be the easiest way to install applications de a USB drive onto Ubuntu?


I have a CNN with 3 convolutional layers, 1 max-pooling layer and 2 fully-connected layers before applying softmax classification. The CNN is trained with Adagrad and I achieve a quite good performance. However, I'm curious as to why my loss is incredibly  very stochastic (see below). Throughout the 30000 iterations it will actually jump above the initial loss. Despite that, the accuracy of the CNN is pretty consistent throughout training. Could this be due to the use of dropout on the convolutional layers and fully-connected layers? If so, where is this mentioned in any scientific articles, lecture notes or tutorials?  Edit: Added parameters below. The learning rate and weight decay is found using gridsearch and different values doesn't change the loss much. It might be that I haven't tuned them completely correct though. Actually, I'm surprised how sensitive Adagrad is to these variables (increasing LR/WD by a factor 10 from these values actually causes my learning to diverge). I'll look into adding a validation/test loss when I have time.   Learning Rate: 0.003 Weight Decay: 0.0005 Dropout: 0.5 Minibatch-size: 10


Problems with matching vector data with raster data

I’m new in Arcgis, and I have some trouble in this task: I downloaded from ICC (www.icc.cat) a raster data map that is a in a specific coordinate system, if I right click to view its properties, it says:  spatial reference : ETRS_1989_UTM_Zone_31N.  but it says nothing about projection reference so if I try to do a Define Projection it warns me that I have one defined and nothing happens.  On the other hand, I have a gpx file with data extracted from a GPS and I found a geoprocessing tool that converts gpx into features. Once I have it converted and situated in my data frame, I can see that the Projected Coordinate system is:  Geographic Coordinate System: GCS_WGS_1984  So, the raster data map and the vector data points does not match on the screen.  Trying to solve this problem, I used a Project tool to convert from GCS_WGS_1984 coordinate system to ETRS_1989_UTM_Zone_31N the vector data, but map and track still don’t match. If I zoom to layer the map is in one site of the screen and if I zoom to layer the track, is in the other site.  I tried different thinks but I cannot succeded on match the data on the screen. I also created another dataframe with an empy projection defined and inserted the map and the reprojected track, but I still have the same problem.  Can someone tell me what I’m doing wrong?  Raster Data   Vector Data


How to remove accounts from “Choose an account” list in Google WITHOUT signing in?

I was helping my mother troubleshoot a problem with her Gmail and now every time I go to use Gmail, her account comes up as the default one. I don't know her password, but I can't sign out of her account without signing in first, so I can't remove it from the list.  This is really annoying.  Is there any way I can remove this entry without having to log in to her account?  All other solutions I have seen to this issue involve somehow signing out of the account before being able to remove it. I cannot do that because when I go to click on the account to switch to it, I am asked to verify that it's me (which it isn't) and type a password (which I don't know.)


404 error for CodeBlocks repository when I update my system

I installed Code:Blocks on my Ubuntu 18.04 LTS. It works fine for now and I don't have any problem with it. But when I update my system using  sudo apt-get update && sudo apt-get upgrade -y   I get an error saying  Err:7 http://ppa.launchpad.net/damien-moore/codeblocks-stable/ubuntu bionic Release   404  Not Found [IP: 91.189.95.83 80] Reading package lists... Done                       E: The repository 'http://ppa.launchpad.net/damien-moore/codeblocks-stable/ubuntu bionic Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.   Now, when I delete http://ppa.launchpad.net/damien-moore/codeblocks-stable/ubuntu bionic in the Software Center, Code:Blocks doesn't run the programs I've written. Having this error doesn't seem to harm anything but it is annoying.   How to solve this? I'm taking C courses in school, so I need some compiler in order to do my homeworks, but I am open to use something different. Thanks


Using residue theorem to integrate from $-\infty$ to $\infty$

I'm trying to integrate $$\int_{-\infty}^{\infty} {x^2 \over {(x^2 + 1)}^2(x^2 + 2x + 2)} $$ given that the function  $$f(z) = {z^2 \over {(z^2 + 1)}^2(z^2+2z+2)} $$ has residues $${9i - 12 \over 100},{3 - 4i \over 25}$$ at the poles $i$ and $-1+i$ respectively. From my understanding of this I have added the two residues (by the residue theorem, and because their respective poles lie in the upper half plane) and multiplied by $2\pi i$ and got an answer of $14\pi \over 100$  Have I done this right?


Why does IEnumerable inherit from IEnumerable?

This might be a old question: Why does IEnumerable<T> inherit from IEnumerable?  This is how .NET do, but it brings a little trouble. Every time I write a class implements IEumerable<T>, I have to write two GetEnumerator() functions, one for IEnumerable<T> and the other for IEnumerable.  And, IList<T> doesn't inherit from IList.   I don't know why IEnumerable<T> is designed in other way.


Can anyone suggest me a book to read about commutative algebra? I want a thorough investigation of the subject. Thanks.


This is the title of a Hallmark movie: A Wish Come True.  Unfortunately I can't speculate anything as why it is come and not comes.  Thank you for your help.


I was reading the book  and came across the section that tried to interpret ridge regression using singular value decomposition (SVD) of the design matrix, $X$. Specifically, I found the following:  $X=UDV^{T}$, where matrix $U$ is $N\times p$, $V$ is a $p\times p$ orthogonal matrix, and $D$ is a $p\times p$ diagonal matrix.   I am confused because from Wikipedia, the orthogonal matrix has to be a square matrix. In this case matrix $U$ does not qualify. Later I tend to believe that $U$ contains orthogonal columns only, and that results in $U^{T}U=I$, but $UU^{T}\ne I$. This seems to make sense because I found in the book   $X \hat{\beta}=X(X^{T}X)^{-1}X^{T}Y=UU^{T}Y$, and $UU^{T}Y$ should not be equal to $Y$  So my question becomes: are there two versions of SVD I can do? One results in both $U$ and $V$ being orthogonal and square matrix, and the other like this? Or is there anything wrong with my argument?  Any guidance is appreciated.  Update after receiving initial answer:  After reading @BabakP 's answer, I thought testing the algorithm using software is a good idea. So I tried svd function in Matlab. The result shows a square U matrix in dimension NxN, a diagonal matrix D in dimension Nxp, and a square V matrix in dimension pxp. Example below:  A=[ones(10,1) randn(10,1)]; [U,S,V]=svd(A); >> size(U)  ans =  10    10  >> size(S)  ans =  10     2  >> size(V)  ans =   2     2    So does this mean R and Matlab give two different versions?


I'm new to Linux.  I now have i386 Desktop Ubuntu 14.04.4 on a PC with Intel CPU.  How do I access the command line to create a -p application folder in the usr\share folder?


How did Einstein derive his most famous equation: $$E=mc^2$$  Is the above equation a special case of  $$E^2=m^2c^4+p^2c^2$$ Its derivation? What is the difference between them?


I am finding it difficult to understand this adjacency matrix property- graph theory

The following properties I am having difficulty with  Let G be a graph with vertices v 1, v 2 , ..., vn  and let A = ai,j be the adjacency matrix of G.    The diagonal entries of A are all 0; that is, a i i  = 0 for i = 1,...,n.  The adjacency matrix is symmetric, that is a  i j   = a j i   for all i, j.  degv i  i is the number of 1’s in row i; this is also the number of 1’s in column i (row  i and column  i   are the same)    I do not get these properties:   The $(i,j)$ entry of $A^2$ is the number of diﬀerent walks of length $2$ from $v_i$ to $v_j$, in particular, the degree of $v_i$ is the ith main diagonal entry of $A^2$.  In general, for any $k\gt  1$, the $(i,j)$ entry of $A^k$ is the number of walks of length $k$ from $v_i$ to $v_j$.  so.. If I have a triangle graph with  vertices = v1, v2 , v3   And Adjacency matrix  $$A=\begin{pmatrix}0 & 1 & 1\\1 & 0 & 1\\ 1 & 1 & 0\end{pmatrix}\text{ then }A^2=\begin{pmatrix}2 & 1 & 1\\1 & 2 & 1 \\ 1 & 1 & 2\end{pmatrix}$$  then the property   $(i,j)$ entry of $A^2$ is the number of diﬀerent walks of length $2$ from $v_i$ to $v_j$, in particular, the degree of $v_i$ is the ith main diagonal entry of $A^2$.  means that from v1 to v1 the number of different walks with length two is 2?  Any help is appreciated thanks


How to prove that if a number is divisible by 2 and 3 both,it is also divisible by 6.It should be proven by using Euclid's Division Lemma.


How to configure compose key in Ubuntu 14.04

I frequently use the compose key to type special characters. I now have a fresh install of Ubuntu 14.04, and in the keyboard settings it says "compose key: disabled". I can't find how to set the compose key.


Choosing $2$ paths through $(0,0)$ to show: $ \lim_{(x,y) \to (0,0)}\frac{xy^2}{x^2 + y^4}$ does not exist

I'm trying to find $2$ paths through $(0,0)$ to show that $\lim_{(x,y) \to (0,0)}\dfrac{xy^2}{x^2 + y^4}$ does not exist.  I only manage to use path $y=x$ but can't find second one. Any thoughts on which path to choose to show that this limit doesn't exist? Thanks!


Is the probability of zero is not impossible according to this YouTube video link?

I found the following link on youtube.com:    $\text{Isn't } \textbf{P(0)} = 0 \;\;?$  I did not understand this video. Can anyone kindly tell me why that is so? Why probability of zero is not impossible?  I am asking the above question because in the following link at the bottom of the website, one of the poster said the probability of zero means impossibility. Then? Where is my error in understanding? I am really confused now. Can anyone kindly elaborate on this paradoxical math problem or is it really a paradox?


How many even integers lying between 1 to 10,000 having distinct digit ???

How many even integers lying between 1 to 10000 having distinct digit??


Can I cover an electrical box with tile?

I had 5 outlets moved to under my cabinets. The Electrician put a junction box over the old outlets. I now need to install backsplash. Can the tile guy cover the box with the backsplash?


Stop an edited deleted answer from bumping the question

I just answered , then deleted the answer because I realized what I said had already been covered. After deleting, I editing in a note saying why I deleted it, but that edit bumped the question on the home page.  I assume that the question will get bumped if I undelete the answer (which is proper behaviour), but I think in the case where someone edits a deleted answer, there's no point bumping the question for content that most people aren't going to see (and since the answer is deleted, shouldn't be seen anyway).  EDIT: A nifty way to abuse the system (10k+ only!).


Separate numerator and denominator integral

I was given $$ \frac{\int_0^{\pi/2}\sin^{\sqrt{2}+1}(x) \, dx}{  \int_0^{\pi/2}\sin^{\sqrt{2}-1}(x) \, dx} $$ How to evaluate this integral? Since denominator and numerator are different Integral substitution will fail , I tried with by part Integral but it lead to nowhere help?


How to make random sequences from array elements?

I made an array containing 24 elements. I want to iterate a loop 24 times, each time taking all the elements from the array and making a unique sequence.   For example:  for(int i=0; i<4 ; i++)   array = [a,b,c,d]   The output I want is:    iteration1: abcd iteration2: acdb iteration3: bacd iteration4: dcab  The specific order is not important. What's important is the sequence for each iteration must be unique.   Can somebody recommend a way to this? Perhaps there is some function for randomisation in C#?


Can someone please help me solve this problem? I am a bit confused.  Embed $R^2$ in the projective plane $RP^2$ by the map $(x, y) → [1, x, y]$. Find the point of intersection in $RP^2$ of the projective lines corresponding to the parallel lines $y = mx$ and $y = mx + c$ in $R^2$ (where $c \neq  0$).  My attempt: So this transformation sends each point in $R^2$ to the line through the origin which is generated by the vector $(1,x,y)$. Then the line $y=mx$ will go to the set   $[1,x,mx],  x \in \Re, x \neq 0 $.  By the same reasoning, $y=mx+c$ will go to the set {$[1,x,mx+c],  x \in \Re, x \neq 0 $}  The problem is I can't quite understand how to define the points at infinity.I don't want to just do the question, I'd like to understand the basics and will be very grateful if someone could help me.


How do you consider an organism to be a new species? Can a new parthenogenetic organism be considered as a new species?


How do I change the icon for PDFs in Win 7

My Adobe Elements PDFs files show a blank white page icon. How do I change the icon that shows for PDFs files in Windows 7?


Got Announcer badge for linking within SE

I shouldn't get it :-) I linked that question from the main CodeGolf site. I am 100% certain that I linked this question only within SE. Why would I link this very particular question from the outside webs?  Is this a bug or a feature?  I think it shouldn't be like that - you should be awarded for your effort outside to let people know about SE. Linking within SE is valuable, but I feel these badges are intended for propagating SE and it should be consistent in that.  EDIT: thanks to the discuters.