How long should my HTML page title really be?

How long should my text within my <title></title> tags really be?  I know Google cuts it off at some point but when?    When I used IIS7's SEO Toolkit 1.0 I get error stating my title should be under 65 characters.  I have a book by Bruce Clay that states I should use from 62-70 characters and roughly 9 +/- 3 words.  I also have used SenSEO's Firefox Add-on and it states I should use a max of 65 characters or roughly 15 words.  What is the max really?  I have 2 sources saying 65 and 1 saying 72 but Bruce Clay is generally kept in high regard.


RegEx for allowing alphanumeric at the starting and hyphen thereafter

I had a requirement where in the text field the first character should be a alpha numeric and then i can allow a hyphen from thereafter in JavaScript.Also hyphen should not be allowed at the end


When I made a playlist from a book from audible it shows up on my iPhone as a playlist but it won't play and in fact says "won't play."  In the past I have done this successfully and I don't know what the problem is. I was so disappointed not to have the ability to repeat An audiobook. I like to have an audiobook repeat if I go to sleep listening to it. In the past I have had a book jump from Austen to Auschwitz and it was very unnerving. I wish they would address this issue and not anticipate how someone is going to use a certain application. I still listen to books on my old classic iPod and you could make playlists from books right on the device it was so easy!   Does anyone know how to address this?


What is the correct way to close my question, whose relevance I am doubting

A couple of days ago  for a problem I had.  I got no answers, but almost by chance I solved my problem.  I am not quite sure if the question and answer are really relevant given that the solution was so simple.  So I have a question on the question:   Should I answer it (moving current Update 2 as an answer) and in a couple of days accept my own answer, so that question and answer are part of the archive? Should I ask for an administrative closing of the question, so the question reminds in the archive but not as an answered question? Should I ask for deletion of the question, so the question is removed for the archive?


Why does floor(pow(64,1.0/3)) return 3 but print 4 when the floor() is removed in C++?

I need to find the floor nth root of a given number(x). x can be as large as 1e12 and n can be as large as 50. floor(pow(64,1.0/3)) returns 3, please help me with this problem, if not can you please suggest an alternative taking the keeping in mind? Edit: I know its about floating point precision, I am asking what the alternative should be in such situations. Even the following code returns True  double x = pow(64,1.0/3); return x==(int)x;


<apex:page controller="Soqlexample3" sidebar="true" >     <apex:form>         <apex:pageblock title="opportunity">            <apex:pageBlockButtons location="top">                <apex:commandButton value="search" action="{!search}"/>             </apex:pageBlockButtons>             <apex:pageblocksection>             <apex:pageBlockSectionitem>                 <apex:outputField value="Enter Name"/>                 <apex:inputfield value= "{!opporName}"/>              </apex:pageBlockSectionitem>             <apex:pageBlockSectionitem>             <apex:outputField value="enter type"/>                 <apex:inputfield value="{!opporType}"/>             </apex:pageBlockSectionitem>             </apex:pageblocksection>         </apex:pageblock>     </apex:form> </apex:page>      Error message: "Could not resolve the entity from <apex:inputField> value binding '{!opporName}'.  <apex:inputField> can only be used with SObjects, or objects that are Visualforce field component resolvable".


camera mobile phone takes pictures at constant focal length if 3.5 mm.supposed to have autofocus and touchfocus

This is a cheap Chinese landvo l200 Android mtk65xx mobile The onlything it keeps Changing is IS0 from 150 to 800 + And exposure time I wondered how can it autofocus and touch Focus when it keeps focal length constant @ 3.5mm. Is that the case with all phones ? Or maybe some high end ones like xperia And HTC have something more in the camera lens


Intel® Wi-Fi 6 AX201 module causing Wi-Fi not detected errors upon fresh install, Ubuntu 18.04LTS

I am running a fresh install of Ubuntu 18.04LTS, and I am noticing that I cannot connect to the wifi. The error shown in settings is "Wi-Fi module not detected". How can I go about remedying this issue?   This is what I see checking to see the status of any networking hardware detected.  lshw -C network    *-network UNCLAIMED               description: Network controller        product: Intel Corporation        vendor: Intel Corporation        physical id: 14.3        bus info: pci@0000:00:14.3        version: 00        width: 64 bits        clock: 33MHz        capabilities: cap_list        configuration: latency=0        resources: memory:d541c000-d541ffff


I'm using a Canon Powershot sx510hs which is an advanced point and shoot camera with 30x optical zoom. It has only one focus point at the center. Whenever I am trying to take portraits, having sky as background, the background appears to be over-exposed. The metering I am using is in evaluative mode or matrix metering mode. I would like to know whether there is a process by which I can attain even exposure for darker foreground subject and brighter background in case of outdoor portrait photography.


Changing background color in a two columns page

I want to have this result: The first column in grey and the second color is white:    I am using \usepackage{multicol}.


Theoretically possible to run two operating systems simultaneously?

A friend of mine asked a question that got me thinking. Is it possible (theoretically, I assume it hasn't been done) to run two operating systems simultaneously on the same computer? Not in the sense of multitasking in one window, but being able to quickly switch from one to the other without restarting. Could something low-level be created that would intercept system calls (or whatever needs to be done) to make each OS think it is running alone? Or hardware itself that would accomplish this?  I'm not talking about dual booting or using virtual machines, but actually running two OS's side-by-side.


Light Source to Affect One Single Object in a Scene

I have an object in a scene that uses multiple light sources, however, I only need the lights to hit the object and nothing else in the scene. Is there any way to fix this problem in Blender currently? Eevee is being used to render.


Can I grep a certain amount of lines before or after a string I want?

Let's say I'm using lshw to get my system memory, and I want it printed out so that I only get the system memory option. Can you specify how many lines you want to print before or after a string in grep? A snippet of the lshw command is output below for reference:   description: Computer     width: 64 bits   *-core        description: Motherboard        physical id: 0      *-memory           description: System memory           physical id: 0           size: 23GiB      *-cpu           product: Intel(R) Core(TM) i5-8350U CPU @ 1.70GHz           vendor: Intel Corp.           physical id: 1           bus info: cpu@0           capacity: 1896MHz           width: 64 bits   I could use lshw | grep size | awk -F: '{print $2}' to get the 23 GiB portion, but I want to see if there's a way to get a block of text with grep to get the full memory section.


Windows 10 high memory usage (unknown reason)

A few days ago I updated my PC to Windows 10. However, after some use my PC started to slow down until it was impossible to use – it was due to high memory usage. After a restart, everything came back to normal (total usage around 25% of 8GB of RAM). However, during a few hours of usage the memory builds up again to 70%, and if not restarted it further goes to 100%, and later on even freezes. Task manager does not help very much as it does not show all the processes (added screenshots below). Also tried RAMMap but it gives an error: "error refreshing database". I tried Googling this question, yet without much success.  I do not know much about PCs, but maybe some of you know this issue, or could help to find out what is using my RAM.


Ensuring Cloned Computer Can Coexist with Original on Network

I've just cloned a computer () and I want to make sure it will be OK on the same network as the original.   I've changed the host name back to what it was pre cloning, so there won't be duplicates on the network, but I want to make sure I make any other necessary fixes before I put the computers running Ubuntu 12.04, on the same network. Is there anything else I need to do before I link them back up?


How to disable thumbnail preview for text file

I am using Ubuntu 14.04 but I miss one great feature of enabling and disabling preview for text file, so is their any way to do so?


Online dome Multiplayer connection error


Is it Ok to lock or unlock my suspension fork while riding?

When I need to switch the suspension fork, should I stop before switch?


As far as I know there are two padding mechanisms, which are PKCS 5 and 7. Which one should be used for CBC?


I guess the title says it all. I want my sections numbered according to the Part I am currently in. For example, if I am working in Part 3, then I want my section to be numbered by 'Section 3.1', 'Section 3.2', etc.  Right now the section numbers continue from the part before. So, in Part 3 the sections are numbered as 'Section 15', 'Section 16', ....  Thank you for your help. I am using article as documentclass.


Word to describe a 'homemade' way to fix something.

I am an artist and making some work, instead of buying some expensive equipment to monitor sound, im just wrapping a microphone in gaffa tape.   Is there a word to describe this kind of thing? Not homemade...not DIY...  Thanks! x


Is there a grammatical term for moving a word to the front or back of a sentence?

There is a function in Arabic grammar where you may bring forward in sentence order a word - as well as deferring it.  For example: if the sentence order is Subject - Verb - Object, you can bring the object forward to be before the subject,  yielding Object - Verb - Subject or Object - Subject - Verb.  Similarly, if you have Noun Phrase - Verb Phrase, you can move the verb phrase forward so you get Verb Phrase - Noun Phrase.  This is used to add emphasis to the item brought forward. The same applies to moving the item to the end of the sentence.  Is there a grammatical term in English that represents this function or functions?


I want to create image box(with image). It's ugly when text is in the top of box.  How can I align text to middle? I tried to use vertical-align, but it seems, that it don't works    EDIT: Your solution works fine with short messages. But if they will be multi-lined, it is ugly again. Is it possible to not increase size of line If we don't need it?


Remapping keys: Caps Lock to Escape and vice versa in Ubuntu 13.10

I just installed Ubuntu 13.10 and miss the feature to swap the escape and Caps Lock key. It used to be possible through a GUI in Ubuntu 12.04. Anyone know how I can solve this?  Thanks for the help :)


Attempting to install R 3.4.2 via tarball in Ubuntu 14.04, No F77 compiler found

Objective: Get R-3.4.2 Working on Ubuntu 14.04  I would like to get R-3.4.2 working on Ubuntu 14.04. I've had no success with apt-get.   What I've tried already  Installing Ubuntu 16.04:   For reasons that escape me, the 16.04 installation doesn't play nicely with my computer--the installation crashes when it attempts to install GRUB and screws up the master boot record. To repair it, I have to boot from media and run an repair utility, at which point I'm back to square one.  Using apt-get install r-base:  It installs R-3.0.x and then attempting to upgrade to 3.4.2 using the instructions  failed. The initial install goes fine, but I have packages that rely on R 3.2 or higher that I need to execute some of my code.  Using the tarball from CRAN:  Opening the INSTALL readme gives the following instructions     As you are reading this file, you have unpacked the R sources and are   presumably in the top directory.  Issue the following commands:   ./configure make   Running ./configure returns      configure: error: No F77 compiler found   which I Googled and came up with a link to this , which recommended that I install the latest version of gcc with yum install gcc, which I tried with sudo apt-get install gccand received a message that gcc is already installed and already the latest version.  My question  What can I do to make the R tarball find the correct gcc compiler upon sudo apt-get configure?


Inside an equation-like environment, I'd like to have some text that is aligned to the left margin of the text block, something like \intertext, but in the same line as the equation  Something like this:  \usepackage{amsmath,mathtools} \newcommand*{\midmathskip}{\hskip0.5\displaywidth\hskip-0.5\totwidth@} \newcommand*{\lefttext}[1]{\llap{\rlap{#1}\midmathskip}}  \begin{align} \lefttext{and similarly}  \hphantom{nn-nn}  \mathllap{hwnn} &= H+hw. \\ \lefttext{Thus}  nn-nn &= 1. \end{align}   of course, the \hphantom and \mathllap are just hacks to make it look right in this case, but I'm looking for something that would work in a gather environment too. flalign could help, for it alters the alignment of the equations (they are not in the center of the text block any more), and it doesn't help with gather anyway.  As a bonus, it would also be nice if it worked with aligned and alignedat.


I have to search a string for words that have a number as prefix or suffix (Example, "abc21" or "943xyz". Then, I need to split the number from the word.  For example, "abc12" has to converted to "abc 12" or "12abc" has to be converted to "12 abc"  However, if the number lies in between letters, for example, "a12bc", then it should be left as it is. How can we do this? Is there a simpler way than regex?


What approaches are there to learn design, coming from a development background?

I'm a web developer trying to become a web designer. But seems that I'm lost in the world of design.  But I don't know what to do, and from where should I start. I'm even unable to find good resources (of course, there are tons of resources out there, but I'm talking about good resources for web-design specifically)  I can tell if a design is good or not, I can offer suggestions to improve the layout or UX. But I cannot pick a color scheme, I cannot create a layout, and I am terrible at generating graphics.  As a developer, how can I pickup design?


Why doesn't Stack Overflow use an AntiForgeryToken?

I was looking into the HTML forms of Stack Overflow and I realized that it doesn't use AntiForgeryToken. So I created a localhost page with the forms of Stack Overflow, posted something and it worked.  So, why doesn't Stack Overflow use it?


Improve guidance for users who are in danger of being quality-banned

I had posted my first question. I got negative feedback and deleted it.    Request No. 1  User should be shown a pop-up message while deleting a post:       "This would be taken into account. So it is better to improve your question and convince people rather than deleting".     If I had gotten this I could surely have preferred this but I was happy after deleting that I had deleted my negative reputation.  I had deleted my own post thrice and got banned from asking more questions. But later I learned that it was being taken into account. On my third time post I was told by some good soul that I was wrong with my formatting, causing negative feedback  Request No. 2  During the posting of answers, the user should be warned/forced to properly format the contents. It should be asked as requirement while posting question if he/she does not do it him/herself.  I came to know the reason for getting negative feedback, when some good soul edited my post and just formatted it voluntarily and then I got positive voting rather than negative.  It was definitely my fault to not read all details from everywhere before posting a question. But I could have been guided better as well.  My ban was lifted (my luck/effort) but I think new users can be guided a bit better to avoid getting banned.


A popular assumption about black holes is that their gravity grows beyond any limit so it beats all repulsive forces and the matter collapses into a .  Is there any evidence for this assumption? Why can't some black holes be just bigger neutron stars with bigger gravity with no substantial difference except for preventing light to escape?  And if neutrons collapse, can they transform into some denser matter (like quark-gluon plasma) with strong interaction powerful enough to stop the gravity?  In  stars are approaching supermassive black hole in the center of our galaxy in a fraction of parsec. The tidal force should tear them apart, but it doesn't. Can there be some kind of repulsive force creating limits for attractive forces?


I have my PS4 connected online in the living room but now I want my PS3 online in the bedroom. When the PS3 tries to connect online I get a message of, “ Cannot connect online using someone else’s ID (email) I’m using the same email address and same password on both consoles on the same network. Why can’t I have both consoles connected online using my same account?


I want to Run  /home/martyn/Desktop/Scanned Items$ python -m SimpleHTTPServer &    in   /etc/rc.local   When I try & do this I get   sh /etc/rc.local: 13: /etc/rc.local: /home/martyn/Desktop/Scanned: not found


Quickest way to find prime factors of a number

I have this number 42900, that contains prime factors 2,2,3,3,5,5,11,13 But I got this by keep dividing until i got a prime factor.  3 * 143 * 100  3 * 143 * * 5 * 5 * 2 * 2   Then for 143, i had to start from 2 to 11 to get 11 * 13  Is there any easy way?


It seems that he is rich.   and     It appears that he is rich.    These two sentences seem to me similar. Is there any slight difference?


Safe and efficient way to keep hands clean while preparing food

In various cooking videos (either online or tv etc) I have seen the cook typically touch either raw chicken or raw meat or raw eggs and then without washing their hands touch other thing like salt and pepper, utensils etc. If they do something before touching anything else it is as trivial as wiping with a paper cloth. I usually wash my hands before touching anything else but this turns out to be tedious and time consuming. So I was wondering if I am doing it wrong and it doesn't really matter or the cooks in the presentations are doing it only for time and is not safe to do or is there something safe in-between the 2 approaches i.e. constantly washing hands vs not washing hands at all


How do I insert special characters into SQL from PHP?

I want to store Spanish characters in SQL (á, é, í, ó, ú, ü, ñ, ¿, ¡).  Consider the following query:  INSERT INTO students (name) VALUES('áéíóú')   When I run the query in phpMyAdmin the characters are stored correctly.  However, when I run the query from my php code they are stored as Ã¡Ã©ÃÃ³Ãº  Here is the relevant code:  <?php ... $query = "INSERT INTO students (name) VALUES('áéíóú')"; ?>


Material Design - bottom navigation with upper tabs?

Prototyping a new dialer app based on Material's framework and style guide. Side navigation is not an option. Instead, I would like to use bottom navigation for 4 main pages/features.   Recent Calls Dialer Contacts (Just a button for the sub-pages)  3.1 All Contacts  3.2 Favorites  3.3 International Contacts Settings   "Contacts" page is actually 3 pages/tabs of 3 types of contact. So my problem is how to display the 3 contact types in the navigation system that suppose to base on Material?  This is the "International" tab example.


I often come across the terms Unity and GNOME while reading about Ubuntu. I understand that Unity is the default desktop environment for Ubuntu. What is GNOME and how is it related to/different from Unity?


I have read that in using unreal conditionals, irrespective of personal pronouns, it mandatory to use subjunctives to form verbs.  " If Jack was playing they would probably win " - if I am correct, the verb 'was' should be replaced by the subjunctive 'were'.   I have taken the above sentence from a famous . Please let me why this sentence is correct ?


I'm trying to make a console app with two double type arrays, but i have a problem. How can i add two arrays into one, but without repeating same number (i have same number in two arrays)?  Thank you very much


Render question title on internal link in comment

EDIT: totally agree with the duplicate. Sorry for taking your time: I did search for 10 minutes before posting this. Cheers.  When I link to another question from a question or answer, the rendered markdown shows the title of the other question, e.g.:    But when we do it for comments, it does not (see my comment below).  I wish it would also render the question title on comments, as it really helps readers to find the new content.


customize top panel clock in Ubuntu 18.04

I want the top panel of Ubuntu 18.04 to show the date, DOW and time.  I tried following this link  but now all I get is a long unintelligible string of letters and numbers.  Anybody have any experience with this?


Export results of MPRI and NDVI to CSV file?

How can I export the result of MPRI or NDVI (which are rasters) to a CSV file? I want to interpret and compare MRPI and NDVI.


Any way to Flavour a Cider crafted with Baking yeast?

I'm very new to brewing, and I'm making a couple test batches of cider as we speak. However my accessibility to things like wine or champagne yeast, so i'm stuck with baking yeast.   My question is when i'm done if i'm not happy with the taste is it possible for me to freeze my cider and add sweetener? Would sugar work or would I have to use a honey or other substitute?


I'm trying to create an interpolation of xyz data in QGIS. The data has successfully interpolated, but there is some strange striping or banding on the final result that I cannot seem to get rid of. See the images   The first (black and white) was created by saving the data points as a shapefile, then interpolating. Parameters in TIN interpolation were cubic method, with x and y set to 5 meters. I let col and row define themselves- how would that affect the result?  The second was with the xyz data loaded as a deliminated text layer. Interpolated the same as above.  The methods with the basic interpolation package do not change the result. Banding appeared with both linear and cubic options. I also looked at contours which exhibit the same problem (see the third image). Data itself is fine.   The banding might have a geographic cause- it is occuring over an area deeper than the surroundings. However, I do not expect it to create this level of an issue.


.shp incompatibilty issue between ArcGIS and QGIS?

I received a .shp file from an ArcGIS user. He said it was in SAD69UTM23S, and indeed it is (checked it in QGIS properties tab). However QGIS is not placing it correctly (using QuickMapServices as reference and other correctly placed .shp files I have; yes OTF reprojection is enabled). I even checked coordinates (of individual points) taken from the attributes table manually converting them and putting in Google Earth, they were equally misplaced.  However, when loaded the original .shp file in Google Earth all the points were in the right places. So I figured it was actually WGS84UTM rather than SAD69 as they said. I changed it in QGIS but it was also misplaced, this time though by a smaller distance.  Is there some kind of compatibility between ArcGIS and Google Earth that doesn't exist between ArcGIS and QGIS?   I don't get it why would Google Earth place the layer correctly but QGIS won't. In fact, apparently Google Earth is using different coordinates for the points (different from those in the attributes table).   Figures below.


Can we exit the event horizon of merging black holes?

I have an intuitive scenario. Consider we have a spaceship just below the event horizon of a BH, which is merging with another black hole.  Finally, the singularities merge and we have a single black hole again.  But, in the transient stage, it is unclear to me if a timelike world-line would exist to leave the system.  I suspect, the metric is probably far too complex for an analytical solution, but in the worst case, it could be maybe solved numerically.  As far I know, black hole merges are examined mainly in an inspiral scenario. I suspect, maybe the escape is possible only if they have a hyperbolic-like orbit (i.e. there is no inspiral, but they simply collide).  Is it possible?


so someone tells me i need to call a few people.  they send me a vCard called contacts.vcf.  i import it.  i open my phone app and start to dial, but wait...i don't know their names.  How do i look up a recent vCard on my phone?  How do i know who's contact i've been sent?  when i navigate to a .vcf file, i can't open it.  all i can do is import it.  polaris office won't import/open it.  is there an android txt editor i can use to peruse a vCard?  yours truly, Confused by vCards Note 3, kit kat


Trying to find a chip and pin card to travel the world with

Please have patience with me as I am very confused about all of this and feeling a bit overwhelmed.  I am about to leave for a year around the world trip (including mostly Europe, South America, Africa and Asia) and I am wanting to have a debit card that will work "wherever" I go.  I am understanding that a "chip and pin" card is needed in Europe. I would like to find a local bank (I am based out of Olympia, WA) that can offer this feature to me. I am also looking for an account that has no foreign transaction fees and no ATM fee charge coming from their end. I know I have to expect to pay for the local ATM fee, of course. And I have found accounts that have these features, but do not feature a chip.  I am also seeing now that most chip enabled cards in the US are "chip and signature" which is also confusing to me.  Can someone please explain in a simple way all of this to me? and maybe help me find a suitable card? I would be very grateful.


i am new to Ubuntu and have installed 13.10 on my new Lenovo G500 laptop and while i am still exploring the os, my mp3 cds & videos on my mobile are not playing and it says plugin required, but i am unable to download the same. I would like to know whether it automatically downloads when i connect to the internet from the software centre or will i have to manually download the same.    Thanks, Yadu*


Laptop PC stuck at startup, formatted, now data unrecoverable, looks encrypted

Someone asked me to recover data from a laptop computer (Sony Vaio), after a Windows reinstall (Windows 8) through the startup recovery procedure.  Prior to that, the computer was malfunctioning : it was stuck on startup, at the login screen, never reached the desktop, even after a whole day. The owner asked her father to fix it, which he did by using the factory restore procedure, since the computer was completely unresponsive. She had not told him that she had personal files on it which were not backed up.  Usually, in such a case, most of the former data can be still retrieved. I scanned the whole drive with R-Studio, then Photorec, but both reputable data recovery softwares found absolutely nothing beyond the current Windows install and the associated softwares, not a single trace of the personal pictures that she had stored on it for instance (the only pictures found are stock pictures from Windows or the installed softwares).  Then I opened the drive with WinHex, to see if it had been completely wiped by a “low level” format : but, second surprise, the main partition was far from empty and appeared full of seemingly random data. (So random in fact that it is not compressible at all : as a test, I extracted three chunks of 1048576 bytes (1MB), compressed them with WinRAR and 7Zip, the resulting compressed files had exactly the same sizes, depending on the compressor used, and slightly larger than the source, 1048844 for the 7Z files, 1048816 for the RAR files – whereas even JPEG or MP3 files for instance can be slightly compressed, by 1-2% on average, despite being already highly compressed.) There's more than 400GB of it, there's not a single sector in “free space” which appears empty, or with any recognizable pattern, this is really puzzling.  So what can it be ? Some kind of drive encryption ? Some kind of virus, maybe a ransomware attack ? The owner uses computers on a basic level, and doesn't remember ever setting up an encryption of any kind. Could the computer have been sold with an encryption system already activated ? Could a security software (a McAfee product is installed as part of the basic install) have implemented it by asking the user a vague question like “do you want to protect your files”, eliciting a clueless “yes” ? If it was a ransomware attack, a “gotcha!” screen would have appeared at some point, at the end of the encryption process, right ? Does that sound like a known issue ? Is what I'm observing (a continuous stream of completely random data) consistent with what encryption normally looks like ? Do ransomware attacks encrypt individual files, or can some of them encrypt a whole partition ? Are there some tests that I could do at this point to determine if this is actually an encryption, and what type thereof ? Is there any chance of recovering anything at this point ?  I asked about that weird issue on HDDGuru, but didn't receive much in terms of useful insights :  (That particular issue is adressed starting from the 9th post, the earlier posts are not relevant – at first I had doubts that the drive itself could be faulty, but it's perfectly fine.)  Thanks.    EDIT : Here's a screenshot of R-Studio showing the partitioning scheme of a complete image from that computer's 500GB HDD.  So there's only one user partition, the 438GB one ; the others are reserved system or recovery partitions. Only the 438GB one is full of seemingly random or encrypted data. The 301MB and 38GB partitions are not displayed by WinHex.  Here's a screenshot of WinHex showing random bytes instead of free space.


What is the difference between 'should' and 'if'?

Should you be lucky to invite the Seoul,   If you are lucky to invite the Seoul,      What is the difference between the two sentences in meaning? And what is the reason we change the order from 'you should' into 'should you'?


footer doesn't appear on bottom of page when using 100vh

Description: I have want to structure my website into several pages using following css: .page {     height: 100vh; }  I add several pages to the website and on the last one I want a footer to appear on the bottom of the page, e.g.   .page {   height: 100vh;   background-color: cyan; }  footer {   position: relative;   width: 100%;   height: 100px;   bottom: 0;   background-color: #000; }
Page 1

Page 2

    What I've tried:  I've tried to set position: absolute (of footer) like in this answer:  I also tried to put a wrapper around the footer with height: 100%; I've also used min-height: 100vh instead of height with no effect  The question: How can I get the footer to the bottom of the page? PS: I don't know if it's relevant but I'm using Firefox v. 85.0.2 (64-bit) Edit: I want the footer to be inside the page, I use these pages to structure my website and the footer should appear on the bottom of the very last page.


Prove that if $x \in R,$ then there exists $n \in Z$ satisfying $x \leq n < x+1$

So this question in my book looks like it's essentially asking me to prove the ceiling function exists.   This question is slightly different to other things I found in related question because we're asked to prove the existence of the value in the middle of the inequality.  My initial thoughts are to define an $n \in N$ such that $n > x$ and $-n < x$  Following from this one can say $-n < x \leq n < x + 1$.  Now here I just lose any sort of direction and instead think of trying another method defining a set and using the properties of $inf$ and $sup$ to move from there. The tricky thing I encounter as a roadblock  is once again the proving of the existence of the $n$ which is different to many related questions.   Any help or solutions are appreciated, ready and rearing to reply :)


Android Stack App crashes when viewing achievements

I am using the Stack Exchange app (v1.0.71) on Android 4.1.2 with kernel version 3.4.0, on an LG Optimus F5.   The app crashes with "Unfortunately Stack Exchange has stopped" when I select the Achievements menu button. Everything else works properly. I can scroll through the feed, view questions, view my site and network profiles, view messages, and upvote comments. I have not tried to create a post since this behavior started.  The crash is only invoked when I tap the Achievements menu icon, and it has happened 100% of the times I've tried this action since the problem began, which was a couple of days ago.


Get the class name using class attributes

I'm create the class  public class MarkerAttribute : Attribute {  }   and set this attribute in MyTestClass  [Marker] public class MyTestsClass {  }   How can I receive the names of all classes which have this attribute in my project?  Thank you.


What are the transactional costs when buying and selling a house?

I am trying to breakdown all transactional costs related to buying and selling a house as well as their numerical values. For instance, the agents get around 3% in commission each, the inspection costs around 500 dollars, etc, etc.  I have thought about these costs:   Agents commissions Closing costs Inspector Lawyer   Feel free to add all the missing ones that come to your mind and an estimate of its respective costs or ratios.


Hilbert's Nullstellensatz implies $I(Z(I)) = \sqrt{I}$

Let $k$ be an algebraically closed field.  Let $I$ be the map that takes algebraic sets in $k^n$ to the ideal generated by them: $I : \{$ algebraic sets $\} \to \{$ ideals of $k[x_1,\dots, x_n] \}$, $I(X) = \{ f \in k[x_1, \dots, x_n] : f(X) = \{0\}\}$.  Similarly let $Z$ be the map that takes ideals in $k[x_1,\dots, x_n]$ to algebraic sets.  Then $I(Z(I)) = \sqrt{I}$.  How does that follow from Hilbert's Nullstellensatz?  This version of Nullstellensatz: If $k$ is an algebraically closed field then, the maximal ideals of $k[x_1,\dots, x_n]$ are of the form $(x_1 - a_1, \dots, x_n - a_n)$ where $a = (a_1, \dots, a_n)$ is a point in $k^n$.


Which is correct: "what if there was" or "what if there were"?

Possible Duplicate:          Is this correct grammar?     What if there was a Stack Overflow on…    Shouldn't it be "what if there were a Stack Overflow on…"?


What F means in lenses and how to find focus distance

I've found some camera sensors with very low resolution to use with electronics. Camera have 150x150px and can mount different lenses type: F2.7, F4.0, F6.0.  I want to ask what F means and if I can use this value to found distance at which the object I'm pointing is in focus.


Mean value theorem for the second derivative, when the first derivative is zero at endpoints

Suppose $f:[a,b]\to \mathbb R$ has derivative up to order $2$, and  $f'(a)=f'(b)=0$.  Prove there is  a point $c$ at $(a,b)$ such that  $$ |f''(c)|\geq 4\frac{|f(b)-f(a)|}{(b-a)^2}. $$    If it was factor 2, not 4, then I could use a Taylor expansion with Lagrange residue.


What does the notation $\Gamma \vDash \phi$ mean (in Mathematical Logic)?  I understand that $\Gamma$ represents a system of formulas, and that $\phi$ represents an individual formula.  I also know that $\Gamma \vDash \phi$ means " $\phi$ is a semantic consequence of $\Gamma$" - but I do not understand what this actually means. Can someone explain this idea to me in layman's terms?  Furthermore, suppose I had the following question:     Let $\Gamma \cup \{ \phi \}$. Does $\Gamma \vDash \phi$ hold for the set of formulae   $$ \Gamma = \{ p \rightarrow q, q \rightarrow r, r \rightarrow s \} \hspace{10 mm} \text{ where } \phi \text{ is } p \rightarrow s $$   Would I attempt this question by trying to prove that, for every formula $\psi \in \Gamma$, the valuation $v(\psi) = T$, based on the assumption that $v(\phi) = T$?


Null date is displaying as 01/01/0001 in code behind of ASP.Net page

i am fetching the date by below code from db using c# ,how to check null date .when date is null then it shows default date on page 01/01/0001 IssueDate = dataReader.GetValue<DateTime>(DbColumnNames.PLAST_ISSUE_DT)


Is there a way to "turn off" creepers in minecraft?

I have this feeling from dealing with the files beforehand that there is some way to turn creepers off, the same way I can mess around with the way some modpacks work. Is there some way I can for instance turn creeper spawn rate to zero or something? That would be lovely.  This is NOT a duplicate of the "how to stop creepers blow stuff up" questions. I asked how to make them disappear, and finally figured it out, using /gamerule domobspawn false to disable all mobs from spawning.


One word for something belonging to an era

Is there a single word which means "of or relating to a particular era"?  I am looking for a word which means that something is limited to a particular era, as opposed to being universal.  Preferably it should be conjugated from the word era, but doesn't have to be.  As an example, things that only existed during the Stone Age, or practices that were only practiced before World War II, or beliefs that were prevalent before the Industrial Revolution, or technology which existed after the advent of computers, could be said to be [insert word here].  EDIT:  I have made several attempts to clarify what I am asking for, and I seem to be having trouble communicating.  "Particular" can mean "an individual object, as contrasted with a universal" - see definition 11 .  I am looking for a word that says a noun belongs to any one era, as opposed to belonging to all eras.  "Food" would not be described with this term, as "food" belongs to any era.  "Automobile" would, as "automobile" only existed during the Modern Era and not before.  "Uncharted territory" only existed in the era before satellite imagery (at least as far as Earth is concerned).  I am not looking for a word which is confined to any one particular era.  I am looking for a word which is confined to any one era in the set of all eras.


Changing projection and extent of raster using gdal

gdalwarp -of GTiff -t_srs "EPSG:4326" input.tif  output.tif   I want to change the projection of input.tif raster (from sinusoidal) and also its global extent to: top:90, left: -180, right:180, bottom:-90  How can I do this either using gdal or rasterio?


If $a_1+a_2+...+a_k=0,$ show that $\lim_{n \to \infty} \sum_{i=0}^k a_i \sqrt{n+i}=0$

If $a_1+a_2+...+a_k=0,$ show that $\lim_{n \to \infty} \sum_{i=0}^k a_i \sqrt{n+i}=0.$  My argument is a bit clumsy for such intuitively obvious proposition: $\sum_{j=0}^k T_j(n)=0$ where $T_j(n)=\sum_{i=0}^k a_i \sqrt{n+j}=0$  and $\lim_{n \to \infty} T_j(n)=\lim_{n \to \infty} T_i(n), \forall i,j$. Are there any more straightforward/alternative way to see this.


Solution of, an ODE related to the modified bessel equation.

I would like to know the general solution of $$x^2 y^{''}+x y^{'} -k^2 x^2 y=0\tag{1}$$ for $y(x)$.  (1) is related to the equation $$\quad x^2 y^{''}+x y^{'} - x^2 y=0$$ , which is the $n=0$ form of the modified Bessel equation  $$x^2 y^{''}+x y^{'} -( x^2+n^2) y=0$$  Other Information.  The material of this question turns up in fluid mechanics, in the theory of the instability of jets.  There is plenty of material on Wikipedia about the Bessel and related equations but I have not found there, the general solution I am looking for.


Does a Finite Field of 36 elements exist?

I'm having a little trouble understanding the finite fields theory, so I'm sorry if my question would seem a little stupid.  I wanted to know if a finite field of 36 elements could exist. Basically, I thought of the field $\mathbb{F}_{37}$, which has 37 elements. But does for example the invertibles of $\mathbb{F}_{37}$ form a field of 36 elements or not? Since all elements are invertible and we have 36 invertibles in $\mathbb{F}_{37}$.


difference between bash, -bash and /bin/bash in ps output

Someone had spawned a while true loop in bash (logged in as root) on a server. It kept spawning processes, which fortunately exited but I needed to kill the parent. I came to know it was spawned directly from command line and not from a script, so I grepped for '-bash' and killed those processes owned by root. It worked fine.   When you do ps aux, In the command column different variants of bash show up.  /bin/bash -bash -bash -bash /bin/bash bash /bin/bash /bin/bash bash   etc..  What are the differences?


Conditional distribution of $X$ given $X+Y$ is a constant

Let $X$ and $Y$ be independent $\exp(1)$- distributed random variables. Find the conditional distribution of $X$ given that $X+Y = c$. ($c$ is a positive constant).   I have tried to solve this using convolution technique and change of variables but get stuck at the integration part. I think I'm over complicating this so I would love to see different approaches solving this. Thanks.


I have a web api service that accepts an image (byte[]) as part of the data for the post/create method.  I save the image data in a sql server blob column.  When I use the corresponding get method I see the data as   "ffd8ffe000104a46494600010100000100010000ffdb004300100b0c0e0c0a100e0d0e..." (shortened)  When I look at the bytes of the original image they look just like that (snip from my binary editor):  ![Manual Method[()  I need a way to convert my data into the correct jpg file.  I’ve tried several things but finally had to manually do it.  I didn't include here my attempts at using Image but they were also many and unsuccessful.  There must be a more standard way of doing what I need to do.  For all of these methods I use the same File writing code:  string base64String = Convert.ToBase64String(photoFromDB, Base64FormattingOptions.None); //various methods to convert that to a byte[] tempBytes string DestFilePath = "testManual.jpg"; System.IO.FileStream fs = new System.IO.FileStream(DestFilePath, System.IO.FileMode.Create, System.IO.FileAccess.Write); fs.Write(tempBytes, 0, tempBytes.Length); fs.Close();   Here are my attempts and the outcomes:  ![All Methods[()              //Manual method that works but I don’t like. byte[] tempBytes = new byte[base64String.Length/2]; string tempString; byte tempByte; int count = 0;  for (int i = 0; i < base64String.Length; i = i+2) {     tempString = base64String.Substring(i, 2);     tempByte = Convert.ToByte(tempString, 16);     tempBytes[count++] = tempByte; }  //Unicode convert //I can see my data here but it has extra nulls included.  tempBytes = System.Text.Encoding.Unicode.GetBytes(base64String);    //UTF32 convert //again can see my data but even more nulls included  tempBytes = System.Text.Encoding.UTF32.GetBytes(base64String);   //UTF7, UTF8, and Default, ASCII, BigEndianUnicodegive me the same output //I can see my data but it isn’t correct yet  tempBytes = System.Text.Encoding.UTF7.GetBytes(base64String); tempBytes = System.Text.Encoding.UTF8.GetBytes(base64String); tempBytes = System.Text.Encoding.Default.GetBytes(base64String); tempBytes = System.Text.Encoding.ASCII.GetBytes(base64String); tempBytes = System.Text.Encoding.BigEndianUnicodegive.GetBytes(base64String);   What’s the secret sauce I’m missing?


Why would an object appear a different size when in water?

A friend of mine has a homework question and we're having some trouble figuring out what physical mechanisms come into play for this.     An underwater swimmer sees a spherical air bubble that appears to have a diameter $d=$ 1.5 cm. What is its actual diameter?   We are having trouble, specifically, thinking of physical mechanisms that would change the apparent sizes of objects when seen underwater. Is it caused by refraction at the curved surface of the bubble?


Drivers for a Intel Desktop Board D865GSA

I have Ubuntu 12.04 installed in my desktop. There is no other operating system installed. Do I need to install my motherboard drivers too (LAN driver, Audio Driver, Graphics driver)?  If yes then where I can get these drivers for "Intel Desktop Board D865GSA" that can be installed in Ubuntu 12.04, as the installation files that I am having are in .exe format which I am unable to install in Ubuntu.


Time dilation under different references paradox

I couldn't figure this out...  I understand that if Alice is moving relatively to Bob at a high speed, Alice's time elapses slower than Bob's. So when Alice is back to Bob and compares the clock, Alice's shows 10:01 but Bob's shows 10:10, for instance. But if we use Alice as the reference, Bob is moving. So Bob's clock should show 10:01... But there is only one outcome, isn't it? I must have messed up something, but I just couldn't find out what.  Help will be much appreciated.  P.S. I've searched around here and found something called "twin paradox". Is that what this is about? If yes, I can go read more about how people solve twin paradox. Thanks.


How to make tables in which the text appears vertically?

I want my table to appear as shown in the figure. Is it possible in Latex, and if it is how can it be done?


I am parsing text for NLP. And I faced unfamiliar grammer below url.  text[:]   I assume text is a natural sentence like text = 'what does Duane Boutte appear in?'. I know : with index number means array access like text[:3] -> 'wha'. But I do not know without index number. And I also know : is used for access to multi dimensional array like data[:][:3].  Could you image above link's text[:]? This function split sentence to tokens.   Update  I found it is a copy operation. See Martijn Pieters and Jean-François Fabre comments


After upgrading from Ubuntu 14.04 LTS to 16.04 LTS, last process left cleaning, how to perform?

While upgrading from Ubuntu 14.04 LTS to 16.04 LTS, every process got done like Getting new packages, Installing upgrades, the last process  was Cleaning. Now, my PC is running fine on 16.04 but while turning it on and shutting it down, it is showing to clean and giving errors. Due to electricity problem, cleaning process while upgrading didn't went well.


What I can do to offset a bad fixed-rate mortgage?

My mortgage came up for renewal right at the time in 2009 when UK interest rates hit rock bottom. This was unprecidented, and most financial advice was to take out a fixed-rate mortgage. So I perhaps went overboard and got one for ten years.  Five years on, interest rates haven't moved and I'm losing money on it to the tune of £100 a month. Obviously, this is ongoing: so that decision has cost me about £5000 in real terms so far. It'll come to a lot more by the end of the mortgage, unless interest rates rise.  Being fixed rate, it's been designed so you can't get out early. If I decide to end the mortage, it'll cost me £1,000 per year of the mortgage remaining - which is roughly what I'm losing anyway, so that seems a bad idea.   I can overpay by up to £500 per month. However, doing this doesn't help pay down the mortgage at all: the total is just added up and will cause the mortgage to end early, by a period dependent on the overpayment total.   This seems to me to be a very bad idea because hoping interest rates rise over the next five years is the only hope I have of making good on some of the losses that I've made.   Is this sensible thinking? If so, is there anything at all I can do to try and ameliorate the financial pain this product is causing me?


Mouseover events in beamer: hovering on \eqref and a comment containing the original equation popping up

This idea came into my mind while I was listening to a speaker presenting his results in a seminar, he used lots of equation references in his later slides, however I can't remember which equation he was referencing to for he gave several models during an earlier stage of the presentation.   We could use hyperref to get hyperlinks on the \eqref, but clicking it would go back to the original page where the equation was labeled, and somehow interrupt the presentation.  I have several workarounds in mind: (1) exploit the \pause option as the overlay, once hitting space, the referenced equation would show. (2) use tikz to insert a minipage into the frame that contains the referenced equation.  However, both solutions require the referenced equation taking up spaces in the current slide the presenter is on, the best solution is still I said in the question title: mouse over the \eqref number, then a comment popping up showing the equation.  My google-fu leads me to a package called comment, however I didn't find any nice examples of how to use that package to produce beautiful slides.  Hence I wonder is it possible to produce some mouseover events like the title said, or any other workarounds are welcome too.


Comment or up vote an other question as a noob

This issue is the exact one I get, but it has not been answered:   I would want up vote it, or something else to show it's still an issue, and to comment on it with my own additions.  Is there any way to do this without reputation, or should I just post a duplicate question linking to that one?  This is not a duplicate of  as this is for someone else's question, not my own. This means I can't edit the issue with more info, as the edit will just get rejected with the comment "This edit is incorrect or an attempt to reply to or comment on the existing post." That is correct, but I can't reply/comment because of no rep.


Is my ATI graphics card supported in Ubuntu?

I have an ATI graphics card and I want to know if it is supported and what kind of drivers should I be running to get the best features out of it.  Is my card supported in Ubuntu and what drivers will work with my card?


Problem listing more than 100 images in index

I have an appendix for a thesis with more than 100 images. The problem I have is that the generated index for those images glues the numbers with the caption.  Here is an image of what is happening:   However, for images below 100, everything seems to be fine:   I am using a template from my university, which I present here:      How can I fix this problem?


I used to run Ubuntu and Kali, but now I want to delete Kali and just extend the partition where Ubuntu is stored. I booted from a LiveUSB and deleted the partition where Kali was installed, and now that partition is unallocated. However, when I try to resize the Ubuntu partition, the slider will not move left. How do I solve that?


What word can I use to describe a relationship between one person and their half-sibling's half-sibling?

Amy is the daughter of Bob and Carol. Bob and Carol, at some point in their lives, married Chelsey and Dan, respectively. Egbert is the son of Chelsey and Bob, while Fabio is the son of Carol and Dan.  Egbert is Fabio's _____.


$X$ is a random variable, if $\Bbb E(X^2)=1$ and $\Bbb E(X)\geq a>0$, prove that $\Bbb P(X\geq\lambda a)\geq(a-\lambda a)^2$ for $0\leq\lambda\leq 1$.

This is a problem in KaiLai Chung's A Course in Probability Theory.     Given a nonnegative random variable $X$ defined on $\Omega$, if $\mathbb{E}(X^2)=1$ and $\mathbb{E}(X)\geq a >0$, prove that $$\mathbb{P}(X\geq \lambda a)\geq (a-\lambda a)^2$$   for $0\leq\lambda \leq 1$.   Let $A=\{x\in \Omega:X(x)\geq \lambda a\}$, we get $$\int_A (X-\lambda a)\geq a-\int_A\lambda a -\int_{A^c}X$$ and $$\int_A (X^2-\lambda^2 a^2)=1-\int_A\lambda^2a^2-\int_{A^c}X^2$$ I want to contrast $\int_A (X-\lambda a)$ and $\int_A (X^2-\lambda^2 a^2)$, but I don't know how to do it, could anyone gives me some hints?


"Open Containing Folder" not using the file manager

When I download anything using Google Chrome or Mozilla Firefox and I use the "Show in folder" option (or "Open Containing Folder" in case of Firefox) it does not work correctly, instead, it open the directory with my text editor Atom...  What I can do to make it work properly?  PS: My OS is Elementary.


The chart shows the percentage of usage of most common means,WHICH ARE   DESKTOP COMPUTER, LAPTOP AND MOBILE PHONE, of access to buy tickets   USED by people from Australia, the UK and Malaysia.   I have many trouble when it comes to use relative clause in order to give complete information.Here I would like to say what the means are and people who used these means are from Australia, the UK and Malaysia.But I am not sure if I can write "the means" just before the word of and when I used the word "used" after tickets, it sounds like I am talking about the tickets but not "the means"..in other way, I want "the means" to be my relative pronoun when I add the word "used" after tickets..  How can we place relative clauses ?


Nonzero $f \in C([0, 1])$ for which $\int_0^1 f(x)x^n dx = 0$ for all $n$

As the title says, I'm wondering if there is a continuous function such that $f$ is nonzero on $[0, 1]$, and for which $\int_0^1 f(x)x^n dx = 0$ for all $n \geq 1$. I am trying to solve a problem proving that if (on $C([0, 1])$) $\int_0^1 f(x)x^n dx = 0$ for all $n \geq 0$, then $f$ must be identically zero. I presume then we do require the $n=0$ case to hold too, otherwise it wouldn't be part of the statement. Is there ay function which is not identically zero which satisfies $\int_0^1 f(x)x^n dx = 0$ for all $n \geq 1$?  The statement I am attempting to prove is homework, but this is just idle curiosity (though I will tag it as homework anyway since it is related). Thank you!


Is the "set" of all algebraic extensions a set?

Consider a field $K$. Now, consider the class of all algebraic extensions of $K$. Is this a set? Since I think it isn't, how to prove it isn't?  If the class were of all extensions of $K$, I think I could argue with Zorn's Lemma to get a maximal element and enlarge it by taking the field of fractions of the polynomials with coefficients in that maximal element (proving, thus, that it is a not a set), but I can't repeat this argument for algebraic extensions. So, what to do ?


I have downloaded data for india as a dbf file then converted it using osm2po to make it routable but the problem is when i make any routing query it takes a lot of time around 300 seconds and these results are after indexing source, target and id columns. So anyone can please tell how to enhance speed of pgrouting algorithm, or which algorithm should be used, time under 5 seconds would be OK for me, thanks in advance


Connection between Kronecker product and bilinear functions

I'm trying to build my intuition about tensors. I know that tensors generalize bilinear maps. And I know that the Kronecker product is a special type of a tensor. But I can't see how the Kronecker product represents a bilinear map.


Is it possible to sandbox JavaScript running in the browser?

I'm wondering if it's possible to sandbox JavaScript running in the browser to prevent access to features that are normally available to JavaScript code running in an HTML page. For example, let's say I want to provide a JavaScript API for end users to let them define event handlers to be run when "interesting events" happen, but I don't want those users to access the properties and functions of the window object. Am I able to do this? In the simplest case, let's say I want to prevent users calling alert. A couple of approaches I can think of are:  Redefine window.alert globally. I don't think this would be a valid approach because other code running in the page (i.e., stuff not authored by users in their event handlers) might want to use alert. Send the event handler code to the server to process. I'm not sure that sending the code to the server to process is the right approach, because the event handlers need to run in the context of the page.  Perhaps a solution where the server processes the user defined function and then generates a callback to be executed on the client would work? Even if that approach works, are there better ways to solve this problem?


I have a MacBook air and want to attach a external graphics card but it's already attached to a monitor, so the thunderbolt port is in use so does anyone know of a hub-like device to make my 1 thunderbolt port have 2 plugs. For clarification I want to take the 1 thunderbolt port in my Mac and add a hub (like 100$ or less) so I can instead have 2 thunderbolt ports. (If it's not clear, I want you to submit possible hubs I can buy (off Amazon if possible))


Numeric operators: if [[ "$#" -ne 1 ]] always outputs true, whereas -- echo "$#" -- outputs 1

I am trying to output success when number of positional parameters is equal to 1, error otherwise.  #!/usr/bin/env bash  foo() {   if [[ "$#" -ne 1 ]]   then echo "error"   else     echo "success"   fi } foo   I execute the script with command ./my_script 1. The output is always error no matter if I run the script with command ./my_script 1 or ./my_script 1 2.   I expect ./my_script 1 to output success.


Should I sanitize an email address before passing it to the is_email() function?

I'm using  to check if a user-provided email address is valid. For example:  $email = $_POST['email']; if ( is_email( $email ) )     // Do something.   To the best of my knowledge, nothing in this function writes info to the database. Should I be sanitizing $email before I pass it to the function?


Error message while updating Ubuntu 20.04 from the terminal

I got the following error message when trying to update Ubuntu 20.04 with sudo apt update. Err:27 http://ppa.launchpad.net/me-davidsansome/clementine/ubuntu focal Release   404  Not Found [IP: 2001:67c:1560:8008::19 80] Err:28 http://ppa.launchpad.net/mefrio-g/plymouthmanager/ubuntu focal Release   404  Not Found [IP: 2001:67c:1560:8008::19 80] Err:29 http://ppa.launchpad.net/vantuz/cool-retro-term/ubuntu focal Release   404  Not Found [IP: 2001:67c:1560:8008::19 80] Reading package lists... Done E: The repository 'http://ppa.launchpad.net/me-davidsansome/clementine/ubuntu focal 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. E: The repository 'http://ppa.launchpad.net/mefrio-g/plymouthmanager/ubuntu focal 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. E: The repository 'http://ppa.launchpad.net/vantuz/cool-retro-term/ubuntu focal 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.


Prove that an algorithm that generates a stable set of a graph can be used in any graph for generating a stable set of maximum cardinal.

Let $A$ an algorithm with polynomial time, which receives an graph $G$ and returns the stable set $S_A(G)$ of $G$ with the property:  $$ \alpha(G) - |S_A(G)| \le  k, $$ for a constant $k\in N$    Prove that $A$ can be used for determining , in polynomial time, a stable set of maximum cardinal in a given graph.  I have tried by taking $T$ isomorphic copies of the graph and I have tried to extend the graph. But I get stuck at this point, can you give me some hints?


Simple insecure two-way data "obfuscation"?

I'm looking for very simple obfuscation (like encrypt and decrypt but not necessarily secure) functionality for some data. It's not mission critical. I need something to keep honest people honest, but something a little stronger than  or .  I'd prefer something that is already included in the  framework 2.0, so I don't have to worry about any external dependencies.  I really don't want to have to mess around with public/private keys, etc. I don't know much about encryption, but I do know enough to know that anything I wrote would be less than worthless... In fact, I'd probably screw up the math and make it trivial to crack.


Is there a difference between a postulate and a principle in physics?  Both seem unproved statements taken as true. If thats correct, why the different names?


When I am idle on Stack Overflow, I see an update of x recent questions were added.   After clicking, the questions load properly, but they do not reflect:   If any of them were already answered.  If any of the existing questions were answered in the idle time.    --  Also, as per Richards comment -  It often happens that one lands in "has been deleted" page off an idle page that has loaded up new questions. Only after a full page reload, all the questions are updated with correct number of answers, votes and views.  --  I would like it if the page refreshes on clicking the load recent questions link so that the questions which were already answered will get highlighted with correct information.


I'm on Ubuntu 18.04.3  I've just finished building my first PC. I have two drives, one is a 240 GB SSD, which Ubuntu is already installed on. The second is a 1 TB HDD. I've already formatted the HDD with one partition, that is the Ext4 filesystem type.  I was wondering how I would go about mounting the drive, where to mount it.


Exporting model to Python script using QGIS?

I want to edit a few things to my model in QGIS 3.2.2, but first I need to convert this model to Python script.   Is there a way to do it?


Connecting LEDs to 4.5 volts in parallel

I'm trying to mod a NERF gun to add LEDs onto it, and I'm trying to wire them in parallel. Unfortunately, when I try to wire them, it doesn't work. I have it wired like this:   The only issue I could possibly see is that I soldered the two wires together and then connected the LEDs to them, but I figured that that shouldn't be an issue because I figured that's how parallel works. The first LED lights up fine, but the second doesn't, and I'm not sure what I'm doing wrong. I was wondering if it was because I was doing it with 4.5 volts, I was going to add some resistors later but I just wanted it working first. Any help would be appreciated.


Please refund to our customer. (This is talking about the receiver of the action, in this case the customer.) Please refund for our customer. (This is talking about the reason of the action)   I am not sure I understand it right. Can the second sentence also be used to indicate the receiver of the action?


Use of infinitive form of verb with another verb

As a native speaker, this sounds incorrect to me:      The company does not permit to distribute the modified materials.   But, I can't explain why it is not so to a non-native speaker. To me, it should be:     The company does not permit distribution of modified materials.   Am I right? What is the grammatical explanation?


How to round a number to a user given number of decimal places

What I'm trying to do is take the user given input (operand) and round my current number to the amount of decimals that the operand is. For example if my current number in the calculator program this is running on is 15.44876, and the user input is 2, I would like the returned value to be 15.45, or just 15.44 at least.  public double round(double operand){     this.answer = Math.round(this.answer, operand);     return this.answer;   I know the code above is incorrect, but it's just a place holder since I'm pretty confused on this.


for a science project at university I have the task to create a web application based on Geoserver. The data is already stored, I have to visualize it now on the web for different users. Each user can only see certain layers.  I only have basic programming skills but experience in Drupal.   Would Cartaro be a good solution for this?


Difference between "at the time" and "at that time"

For example,     This early 1980s incident made headlines at that time.   versus     This early 1980s incident made headlines at the time.   Which is correct and why?


Is it possible to find the length of an array if I have only the pointer to the first array element taking into account Array Decay?

I'm creating an integer array whose input will be given by user, and I'm passing it to a function where it is decaying to a pointer(say int * a), now how can I obtain the length of the array in my function using only the available resource, that is the pointer to the first array element?  I have tried "templates"(template) which works on array and not on pointer. I did not want to use "struct"(putting array inside struct and passing the struct to function) as it just avoids the problem. I also did not want to stash the size in one block extra in the array as I did not want to consume more memory than what is required(even though it is a mere one). I also did not want iterators("begin" and "end"), they mostly do not work on pointers. I did not want a C++11 solution or a boost library solution too as I did not want to depend on version or a library.  #include <iostream> using namespace std; void func(int *a) {  //Now entire programming is to be done here as array has been passed  //How to find length using pointer a only, so that I can proceed with  //array operations?  //This function is not aware of length because of Array Decay but  //atleast has a starting point that is the pointer. } int main() { int array[5]={2,3,4,5,6}; func(array); //main()'s use is over now, control is shifted to void func(int *) return 0; }   I expect a method to find length using the pointer only, that is I expect the number 5(length of array) to get generated somehow inside func() method.


How do you explain a significant variable (p-value less than 0.05) in a linear regression equation in layman terms?


Can a caster Counterspell a Counterspell against a non-cantrip spell they cast?

If caster A (for example a wizard) casts a spell on their turn, and it is Counterspelled by another caster B, can the original caster Counterspell the first Counterspell?    I am assuming that it is legal to Counterspell a Counterspell if it is done by different individuals, though please correct me if I'm wrong.  I also assume the answer to this question also applies to a caster using their reaction to cast any other non-cantrip spell on their turn, such as casting the Shield spell when taking an opportunity attack when leaving melee, after they have cast another spell with their action.


Short story about an astronaut that enters an alien space ship and discovers it is a sarcophagus

Upon realizing it is a sarcophagus, he decides to sacrifice himself (I think by disconnecting his air) and exist in it for eternity along with the original creature. It may have been in an old Omni magazine, or some other periodical. I thought it may have been in the anthology "Dead Astronauts" but I did not find the story in there.


Why did I receive a message saying I have been granted a privilege, yet I don't have enough reputation?

The site shown a message saying I have been granted a privilege, but the reputation required for that privilege is higher than the one I actually have. What happened?


According to the doppler effect , if my source is faster than sound , will I hear the sound backwards?

In a hypothetical situation,say I have a sound box with a very large volume and let's say it is placed pretty far away from me. If it travels towards me at a speed higher than that of sound in the same medium, air for instance, then will I hear the song playing backwards?  according to the equation  f' = [v+vo/v+vs]f where all symbols have their usual meaning , I get a negative f` for vs>v . What does a negative frequency indicate? I understand a similar question has been asked however the answers didn't satisfy me. I still believe that before the first pulse reaches the observer , the second pulse is created and so on until the observer hears the 'n'th pulse and then the pulses preceding it.


Is it safe to invest in cryptocurrencies such as bitcoin?

How safe is it to invest in cryptocurrency? I see bitcoin going up almost every time I look at its market value. How can anyone be sure it wouldn't crash in the future?


Why did the Mithril coat fail to stop Shelob's sting?

Did Frodo take it off? Or was the fell spider's sting simply too strong to be stopped by Mithril?  If it is the latter, that would be pretty surprising, because that would mean Shelob could possibly sting a sleeping dragon! (I remember Gimli saying "Mithril... hard as dragon scales!")


'locate' command in terminal. Why is it so fast?

Searching a keyword in linux terminal using the locate command gives answer in a short time. What is the search algorithm used?


Desktop only visible on small portion of the screen on old Dell Inspiron 1100

I have an old dell inspiron 1100 laptop and I installed ubuntu 12.04.2 dual boot with windows xp. Everytime I log into ubuntu, the screen appears always on the left hand corner, never full. This laptop has the capacity to 1024 x 768, but always says 640 x 480. I tried uninstalling and reinstalling, but still the same errors. I thinking of installing 14.04 but I have the feeling that the same error will occur. I even tried downgrading to 7.04, but error with intel.  I even did a bios flash from A22 to A29, and nothing changed.  VGA compatible controller (0300): Intel Corp 82845 G/GL (BROOKDALE) Subsytem: dell Device (1024:0149) Kernel modules: intelfb, i915   I have no idea what else to do. Please need guidance and step by step instructions. I like the feel of Ubuntu 12.04 as a desktop.  Intel pentium 4 2.20ghz level 2 Cache: 512kb System memory: 640 mb video controller: intel 845GL UMA video memory: 1 MB Audio Controller: Sigmatel 9750 Modem controller: PCTel 2304WT


How to disable Google One Tap sign-up prompts?

I've recently begun seeing common pop-ups on sites on which I do not have an account. The pop-ups prompt me with my real name and Google sign-in email, which is being provided either by being signed in to Google/Gmail or being signed in to the desktop Chrome browser.  Sign in to example.com with Google Your Name email@example.com CONTINUE AS NAME To create your account, Google will share your name, email address, and profile picture with example.com. By continuing, you agree to example.com's privacy policy and terms of service.  The functionality providing this seems to be variously called: "Google ", "Google ", "You Only Log-in Once", the GoogleYOLO API for OpenYOLO, "Google One-tap sign-up and automatic sign-in", "Google Account sign-in prompts", "Sign in with Google", "Log in with Google", "Join with Google".  One-tap sign-up and automatic sign-in  You can provide seamless authentication flows to your users with Google's one-tap sign-up and automatic sign-in APIs. With one-tap sign-up, users are prompted to create an account with a dialog that's inline with your page's content, so they're never taken out of context by a sign-up page. With just one tap, they get a secure, token-based, passwordless account with your service, protected by their Google Account. And, of course, since there's such little sign-up friction, users are much more likely to register.  I frequently see the pop-up, obscuring the content, .  It is also being added to :   Large websites using this sign-in method include:   Sign in to medium.com with Google Sign in to nytimes.com with Google Sign in to eBay with Google Sign in to Quora with Google Sign in to trulia.com with Google Sign in to Tripadvisor with Google Use Pinterest with Google Use hipmunk.com with Google Create a wayfair.com account with Google    I don't object in principle to using my Google account to sign up for a service, but I do not want these pop-ups obscuring the site contents on page load. This pop-up feels like a "notification" from Chrome, prompting me to use my signed-in Chrome account. It appears to be something I should be able to disable, like , in my local copy of my web browser software. Or, if not a Chrome browser notification, it also feels like something I should be able to disable from my Google account settings. How do I disable these pop-ups and ensure they are not shown on any website? Settings-type changes preferred over content blockers, if possible.


Reading these questions and answers:        brought me another one that will create problems for new users of that command:   How to configure pkexec for easy usage?   For example when doing the following:  (Opening a file in terminal)     pkexec nano /etc/mysql/my.cnf     (Opening a file in GUI)     pkexec gedit /etc/mysql/my.cnf     The last one gets the following error:   pkexec must be setuid root   Now this brought me the following questions:   How to configure pkexec to avoid getting this? Similar to how sudo/gksu behave when doing the same thing (they only ask for the password). If applicable, how to tell it to not ask for a password after the first time applying it to a command (or including the first command if configurable)? Where to save the configuration file if not yet existing? Is there a GUI app to configure pkexec usage (Policy Kit)?


(focal)kia@localhost:~$ sudo apt-add-repository "deb https://dl.winehq.org/wine-builds/ubuntu $(lsb_release -cs) main" Get:1 https://dl.winehq.org/wine-builds/ubuntu focal InRelease [6,257 B] Err:1 https://dl.winehq.org/wine-builds/ubuntu focal InRelease             The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 76F1A20FF987672F Hit:2 http://archive.ubuntu.com/ubuntu focal InRelease Hit:3 http://archive.ubuntu.com/ubuntu focal-updates InRelease Hit:4 http://archive.ubuntu.com/ubuntu focal-security InRelease Reading package lists... Done W: GPG error: https://dl.winehq.org/wine-builds/ubuntu focal InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 76F1A20FF987672F E: The repository 'https://dl.winehq.org/wine-builds/ubuntu focal InRelease' is not signed. 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.  How do I fix this?


could someone explain why I get this weird result by executing following code?  '1.0.0.0'.split('.').map(parseInt);   Output:  [1, NaN, 0, 0]


The definition of 'word-for-word translation'

Could I have the accurate definition for "word-for-word" translation?


Today when deploying our code base we've run into the following error:  lwc/orderGrid/orderGrid.js-meta.xml -- Error: Failed to save Lightning Component Resource  [lwc/orderGrid/orderGrid.js] of Lightning Component Bundle [orderGrid].  Error: Value too long for field: Source maximum length is:131072   Looking at the size of file in question it is really bigger than 131,072 bytes. But we cannot find in documentation anything regarding limit for js file as a part of lwc component.  Can anyone point us in the right direction? Is it a real restriction or just some  SF bug?


What are the limits on the area affected by an Alarm spell?

I am fairly new to D&D, and I am trying to figure out the line between using spells creatively and abusing the spell. With regard to the  spell, the text reads:     Choose door, a window, or an area within range that is no larger than a 20-foot cube.   How I read this is that you can designate any contiguous area within the spell's range with a total volume less than that of a cube with a side length of 20 ft., so 20 ^ 3 = 8,000 ft.   It so happens that the volume of a 30ft hollow hemisphere with 1ft thick sides is 8,060.83 cubic feet (I used  to find the area of a partial sphere with a radius of 29ft and a height of 28ft and subtracted that from the volume of a 30 ft radius sphere). That can be easily made to equal 8,000 cubic feet with only minor adjustments.   Is this use of alarm allowed according to a strict interpretation of the rules and do you think would it be acceptable to use in game play?


Set projection/CRS in map and shapefile to produce buffer

I simply want to create a buffer of a specific size, around a single point. When I create a buffer it uses degrees/ or radians, or whatever, and the buffer is created that covers the whole screen.   I am working on a South African map, so I have tried setting the project CRS to WGS84/UTM30S.  I then load my shapefile, and set the shapefile CRS to WGS84/UTM30S. Still the buffering tool creates this massive buffer.   I just want to be able to create a buffer, of known radius in meters.    I am using QGIS 1.8.0 Lisboa  Anyone with ideas?


Prove there is an L-structure (M,I) such that it is equivalent to sigma and has infinitely many elements

Let L be a language and let $\Sigma$ be a set of first-order L-sentences. Suppose that, for every natural number k, there exists an L-structure (M,I) such that (M,I) $\models$ $\Sigma$ and M has exactly k elements. Use the compactness theorem for first-order logic to prove that there is an L-structure (M,I) such that (M,I) $\models$ $\Sigma$ and M has infinitely many elements. Been a lil stuck on this question, I understand it somewhat but not sure how to incorporate the M being finite. One part that has struck out is that deductions must be finite.


Cauchy's Integral theorem: Let $U$ be a convex open set and suppose $f$ is a function which is analytic on $U$, except possibly at one point, where it is at least continuous. Then $$\int_{\gamma} f(z) dz=0$$ for every closed path in $U$.   Let $\gamma$ trace the unit circle centered at $0+0i$ in the anticlockwise direction on the set $\mathbb{C}$.   Then, $\int_{\gamma} \frac{1}{z^2} dz = 0$, which makes sense.   But then why does $\int_{\gamma} \frac{1}{z} dz = 2\pi i$?   Both $\frac{1}{z}$ and $\frac{1}{z^2}$ are not defined at $z=0$, but then how does Cauchy's theorem only apply to the latter?


Proof that $f(x)$ has two roots over $(0, \pi)$ at least! And other developing question.

Question 1: Let $f(x)$ be a continuous function over $[0, \pi]$. Then the definite integration of $f(x)\sin{x}$ and $f(x)\cos{x}$ over $[0, \pi]$ are all 0.      Prove that $f(x)$ has at least two zeros over $(0,\pi)$.   It is easy to see that $f(x)$ one root over $(0, \pi)$ But it is difficult to show $f(x)$ has at least two roots over $(0, \pi)$.  Question 2:  Let $f(x)$ be a continuous function over $[a, b]$. Then the definite integration of $f(x)$ and $f(x)g(x)$ over $[a, b]$ are all 0. And g'(x)~=0(over $(a, b)$).     Prove that $f(x)$ has at least two zeros over $(a,b)$.


Evaluation of $\lim_{n\rightarrow \infty}\binom{2n}{n}^{\frac{1}{n}}$

Evaluation of $$\lim_{n\rightarrow \infty}\binom{2n}{n}^{\frac{1}{n}}$$ without using Limit as a sum and stirling Approximation.  $\bf{My\; Try:}$ Using $$\binom{2n}{n} = \sum^{n}_{r=0}\binom{n}{r}^2$$ Using $\bf{Cauchy\; Schwarz}$ Inequality $$\left[\sum^{n}_{r=0}\binom{n}{r}^2\right]\cdot \left[\sum^{n}_{r=0}1\right]\geq \left(\sum^{n}_{r=0}\binom{n}{r}\right)^2 = 2^{2n} = 4^n$$ So $$\frac{4^n}{n+1}<\sum^{n}_{r=0}\binom{n}{r}^2=\binom{2n}{n}$$ But i did not understand how can i calculate upper bound such that i can apply the Squeeze theorem.


I always say "mathematics is funny" (ok, maybe many of you disagree about the adjective), but then I noticed that "mathematics" seems to be a plural, like the Greek word from which it derives.   Am I correct in using the verb in singular form? And are there other words like this one?


Can I do some thing like this in MySQL? I want to have a unique id generate by the database automatically but not using auto_increment.  CREATE TABLE cust(      CustomerID uniqueidentifier NOT NULL DEFAULT newid(),      Fax varchar(15) NULL );   I have try this, but there has an error #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'uniqueidentifier NOT NULL DEFAULT newid(), Fax varchar(15) NULL )' at line 2


I want remove the space in my table of contents of \section, \subsection and \subsubsection.  This is my code:  \documentclass{book} \usepackage[utf8]{inputenc} \usepackage{imakeidx} \makeindex[columns=3, title=Alphabetical Index, intoc]  \begin{document}  \tableofcontents \chapter{chapter} \section{Introduction} In this example several keywords\index{keywords} will be  used which are important and deserve to appear in the  Index\index{Index}.  \subsection{subsection} Terms like generate\index{generate} and some\index{others}  will also show up. Terms in the index can also be  nested \index{Index!nested}  \clearpage  \section{Second section} This second section\index{section} may include some special  word, and expand the ones already used\index{keywords!used}.  \printindex \end{document}


UK citizen, US company, living in UK: Can I use an ESTA?

So:   I am a UK citizen I work for a US company I currently live in the UK and have no US visa   What am I allowed to do when I enter the US on an ESTA? Am I allowed to work if I am getting paid in a UK bank account? Obviously a potentially contentious issue and I'm keen to get it right!


If Euler Totient function fails other methods to find the remainder for the modular exponentiation

Modular exponentiation using Euler Totient Function for the below question.  $$ 128 ^{343} \mod 527 $$ using totient function. Is there any other method to find the remainder of the question if totient function fails? Please provide me some valuable answer in Euler totient function or give the other methods to learn


Prove that $|\sin x-x |\le \frac{1}{6}|x|^3$  I've been trying to solve this problem for the last hour but I just can't crack it. I know I'm supposed to use Cauchy's Mean Value Theorem somehow but can't figure out how.  Edit: This problem is from chapter 4 of Foundations of Analysis by Taylor. The book hasn't covered Taylor series yet. I am supposed solve this using a method that is already covered. It is very likely that the intended solution involves the usage of Cauchy's form of the mean value theorem.


Java not initialising a class, returning null exception error

getting a frustrating null exception error when the class junction is being used in functions. The class should be initialised so this shouldn't be an issue. Help ;_;  class RobotData { class Junction {     public int juncX;     public int juncY;     public int arrivalHeading; }  private static int maxJunctions = 10000; //Max junctions likely to occur private static int junctionCounter; private static Junction[] junction;  RobotData() {     junctionCounter = 0;     junction = new Junction[maxJunctions]; }  public void resetJunctionCounter() { junctionCounter = 0; }  public void recordJunction(IRobot robot) {     junction[junctionCounter].juncX = robot.getLocation().x;     junction[junctionCounter].juncY = robot.getLocation().y;     junction[junctionCounter].arrivalHeading = robot.getHeading();     junctionCounter++; }  public void  printJunction() {     System.out.println(junction[junctionCounter].juncX);     System.out.println(junction[junctionCounter].juncY);     System.out.println(junction[junctionCounter].arrivalHeading); } }   The class RobotData is being initialised properly, but when the functions are being called I get the null error indicating that junction[junctionCounter] hasn't been initialised yet. Unsure why (obviously) as it should be initialised when RobotData is.


Biblatex: tricks with repeated citations in footnotes

I'm trying to adapt the citation formatting provided by the verbose-trad2 style for biblatex to conform to very particular specifications I've been given. I think verbose-trad2 is the closest to all my needs amongst the default ones.  The citations are to be given in footnotes, usually as \footcite{}, but occasionally with \footnote{Some remark... \cite{}.}. What I call here a full citation is the whole info on a work: author, title, publisher, date, etc. What I call an abbreviated citation is just author (always complete!), abbreviated title, and optionally the page number. The first time a work is cited, I must use the full citation, and then it depends on whether other works are cited in between or not, but never more than the abbreviated citation.   The biblatex related code I've already come up with can be found . The LaTeX document itself is an article with the option onepage.  First, two hacks I have already applied.   Always print the full name of the author. Thus I set idemtracker=false. The word Idem must be used when two subsequent citations share the same author and title (instead of the default Ibid in verbose-trad2). Thus I redefined ibidem = idem.   Second, there are things I still need to adapt, for which I don't have the faintest idea, even after looking through the documentation and this site. (I may have missed something, because I'm not at ease with low-level tex or biblatex code, I apologize if that's the case.)   When two subsequent citations share the same author, title and page number (given in the square bracket argument of the \footcite[]{} command), just print Ibid. (nothing else). Always begin the foonote section of a new page with a full or abbreviated citation (author (full), abbreviated title, page number), never start with an idem or ibid. even if the last citation on the previous one is similar/same. I thought the biblatex documentation implied this would work out of the box, but it doesn't seem to. (Optional) Abbreviated title means: if there is only one work by the author, use the expression op. cit., else use an abbreviated form of the title (do I necessarily have to use the shorttitle field in the bibTeX entries?)   Thanks in advance for any suggestions and help!


If $I = \langle 2\rangle$, why is $I[x]$ not a maximal ideal of $\mathbb Z[x]$, even though $I$ is a maximal ideal of $\mathbb Z$?

Let $I = \langle 2\rangle$. Prove $I[x]$ is not a maximal ideal of $\mathbb Z[x]$ even though $I$ is a maximal ideal of $\mathbb Z$.   My professor mentioned that I should try adding something to it to prove that $I[x]$ is not the maximal ideal. I want to assume he meant to add $ \langle 2 \rangle$ to $I[x]$?


Problem RTL8188EUS driver on ubuntu 20.04

I have a new USB WiFi adapter Downloaded driver from  and installed using sudo make all sudo make install  Everything went well, however no wifi signal showing. Output of lsusb Bus 002 Device 004: ID 0bda:f179 Realtek Semiconductor Corp.   Output of iwconfig eno1      no wireless extensions. lo        no wireless extension


I posted a few questions on Stack Overflow and every time someone edits my question and remove the first sentence like "Hi all" and the last one like "thanks, Rémi"...  What the problem with being polite? Do we have to speak like a machine?  Example:   "polished" means "poli" in French which means also polite, so that's kind of fun here.


Is it rude to say commands or imperatives without saying please?

I've been wondering that for a long time. And if it is rude, then why does everyone say commands/imperatives without saying please? I personally phrase them into questions, or say "you have to","you need to","you can't"...and such. Does anyone else do that? Just me? I feel like everyone is bossy but me lol.  Also, I was wondering if saying "come on" is rude. It sounds mean or just negative when people do. Also when people say "let me" it also sounds mean-ish because it sounds like you are commanding permission from someone without them having any say.


SQL: Combining two select queries, using results from the first

I know this will either use a left join or left outer join or something like that, but these types of queries always throw me off.  I have two tables:  categories  ID    CatName          CatSlug 1     Big Shirts       big-shirts   items  ID    ItemName         Category    Price    ... 1     Big Red Shirt    1           20.00   So I am trying to return all items in a given category, queried by the category slug. I also need to return the category name. So now, my two queries are like:  $return = array();  $query = "SELECT * FROM categories WHERE CatSlug = :CatSlug LIMIT 1";   $param = array(     'CatSlug' => $slug );  $result = $this->Db->selectOne($query, $param);  if ($result) { // If result exists      $return['Category'] = $result['CatName']; // Need to return cat name      $query = "SELECT * FROM items WHERE Category = :Category";       $param = array(         'Category' => $result['ID']     );      $result = $this->Db->selectAll($query, $param);      if ($result) { // If result exists          $return['Items'] = $result;      } else { // If result does not exist          $return['Items'] = array();      } // End if result does not exist  }  return $return;   So, I am returning an array with two keys: Category contains the CatName value in the categories table, and Items contains an array of all items inside that category, or a blank array if there are none.  How can I combine these two queries?


I set an object equal to the other that invokes the copy constructor. My problem is when I test if the two are equal to another my output says that they are not. One method is through an overloaded constructor and the other is from a copy constructor that both output the same thing.  public class HotDogClass {      private int standNumber; // ID number for hotdog stand     private  int soldToday; //dogs each stand sold     private static int totalSales;      public void setstandNumber (int newstandNumber ) { standNumber =      newstandNumber; }     public int getstandNumber ( ) { return standNumber; }     public int getsoldToday() { return soldToday; }     public void setsoldToday ( int st ) { soldToday = st;         if (soldToday <= 0)          System.out.println("no hotdogs sold");}     public static int gettotalSales ( ) { return totalSales; }       static  {         totalSales=0;         System.out.println("Static initializer block\n" );     }     public HotDogClass () {          this ( 0, 0);         System.out.println("Default constructor");     }      public HotDogClass (int sta, int st) {         standNumber = sta;         soldToday = st;         totalSales += soldToday;         System.out.println("overloaded contructor");     }     public HotDogClass (HotDogClass original) {         this.standNumber = original.standNumber;         this.soldToday = original.soldToday;         //totalSales += soldToday;         System.out.println("Copy contructor");     }     public void justSold ( ) {          soldToday++;         totalSales++;     }      public String toString ( ){          String x = "Stand number " + standNumber  + " sold " + soldToday + " hotdogs" ;         return x;     }       public void dispose ( ) {         System.out.println("HotDogStand - dispose method");     }        public void finalize ( ) {         System.out.println("HotDogStand - finalize method");     } }  public class HotDogStand {      public static void main(String[] args) {          HotDogClass stand1 = new HotDogClass(21, 10);         System.out.println (stand1 + " \n "  );         //stand1.justSold();         //stand1.justSold();         HotDogClass standCopy = new HotDogClass (stand1);         System.out.println( standCopy + "\n");         if (standCopy.equals(stand1))             System.out.println("Stand1 and Standcopy are equal\n");         else             System.out.println("Stand1 and standcopy are not equal\n");          HotDogClass stand2 = new HotDogClass(32, 7);         System.out.println (stand2 + " \n ");         stand2.justSold();         stand2.justSold();         stand2.justSold();          HotDogClass stand3 = new HotDogClass();         System.out.println(stand3 + " \n ");           HotDogClass stand4 = new HotDogClass();         stand4.setsoldToday(0);         stand4.setstandNumber(10);         System.out.println(stand4 + " - Testing my set and get methods\n");          System.out.println("The ending total of all hotdogs sold is "                  + HotDogClass.gettotalSales());      } }


Pigeonhole Principle for numbers and their divisors within a set

I am having a hard time thinking about how to cast the below problem into a form that can clearly make use of the Pigeonhole Principle.   Suppose we are given a set $T = \lbrace 1, \cdots, k \rbrace$ for a positive even integer $k$. I would like to show that for any $S \subseteq T$ such that $|S| = \frac{k}{2} + 1$, there exists $x,y \in S$ with $x \neq y$ such that $x$ divides $y$.  The most basic pigeonhole principle basically assumes we have $n+1$ "elements" that we would like to insert into $n$ "boxes" and the principle tells us that we can expect at least 2 elements to be in at least one of the boxes. This principle can be used to prove a lot of things but most examples I have found have pretty obvious "elements" and "boxes", while in this case I am not seeing anything obvious.  It seems at first that one would want to perform $y \mod x$ for each valid pair of $x,y \in S$, but this does not seem smart because then it is not clear what the buckets should be since using $k$ buckets from $0$ to $k-1$ seems not really great when the modulo is done for values that may not be $k$.  Can anyone provide a hint as to how I might approach the problem using this technique?


copy/paste style to multiple layers in QGIS

I have many shapefiles in QGIS. How can I paste the style of one layer to all the other ones? So a "batch" copy and paste solution.  If I make a multiple selection the the paste style option is not available anymore.


Show that there exists a $c\in \mathbb{C}$ such that $f(z)=c \bar{z}$ for all $\vert z\vert=1$.

The problem is:  Suppose that $f(z)$ is continuous on a domain $D$ that contains the unit circle, and that $f(z)$ satisfies: $$\vert f(e^{i\theta})\vert \leq M \; \forall \theta \, \in [0, 2\pi )$$ and $$\bigg \vert \int _{\vert z \vert=1} f(z) \text{d}z \bigg \vert =2\pi M $$ show that there exists a $c\in \mathbb{C}$ such that $f(z)=c \bar{z}$ for all $\vert z\vert=1$.  I've tried lots of different approaches such as defining a function $g(z)=\frac{f(z)}{\bar{z}}$ and trying to show that $g'(z)=0$ so that $g$ is constant on the circle, or trying to use some bounding theorems for analytic functions to show that $g$ is constant but this requires $g$ to be analytic. Some other methods were using the Cauchy-Riemann equations but I couldn't find any reason why $g$ should be analytic.  Any help would be greatly appreciated, thanks!


I have a file "commands.php" that dynamically generates bash commands. For example, one line is:  # - commands.php ssh me@123.123.123.123 echo "text" > file; reboot;   How can I use the output of xargs to execute these commands... eval, maybe?  cat commands.php | xargs -L 1 -I {} 'eval "$({})"';


I Have a question. Given only the definition of equality of two sets, how can we prove that there is one and only one empty set. I mean by equality of two sets the following: $$A=B \iff  \forall x (x \in A \iff x \in B)$$


fsck not working to fix corrupted external drive

I am using an early 2011 MacBook Pro with the Mavericks OS. I've researched a similar issue on an  but As far as I know, being in Single User mode won't help my situation.   One of my external drives with all my photos stopped working - it does not mount, even though I see it in Disk Utility. Using DU I tried to verify and repair the disk and got this message:  'Invalid B-tree node size'  Following the advice in this :  I tried to list my drives with the Terminal command  df -hl  The specificied disk was not in the list When I tried the suggested tail command  tail -f /var/log/fsck_hfs.log  I saw the name of the disk as   /dev/rdisk3s2: ** The volume   could not be verified completely.   Following that, I used this command (also suggested in the above link)  sudo fsck_hfs -r -d /dev/disk3s2  Instead of the expected proper outcome, what I received was an error message in Terminal as below:  inancs-MacBook-Pro:~ INCA$ sudo fsck_hfs -r -d /dev/disk3s2 Password: journal_replay(/dev/disk3s2) returned 0 ** /dev/rdisk3s2     Using cacheBlockSize=32K cacheTotalBlock=65536 cacheSize=2097152K.    Executing fsck_hfs (version hfs-226.1.1). ** Checking Journaled HFS Plus volume.    Invalid B-tree node size (3, 0) ** The volume   could not be verified completely.     volume check failed with error 7      volume type is pure HFS+      primary MDB is at block 0 0x00      alternate MDB is at block 0 0x00      primary VHB is at block 2 0x02      alternate VHB is at block 1464477326 0x574a268e      sector size = 512 0x200      VolumeObject flags = 0x07      total sectors for volume = 1464477328 0x574a2690      total sectors for embedded volume = 0 0x00      CheckHFS returned -1317, fsmodified = 0   What are my options? I have Data Rescue but not Disk Warrior (low on budget these days). Is there a possibility to fix the drive?  If not, and if I can rescue my data and put it on a different disk, is it safe to format the current drive and re-add my photos or should i stay away from this disk?


Using a quote to begin a new chapter in a thesis

I am doing a Masters thesis. Can I use a quote to begin each chapter of my Master's thesis?


jQuery click function not firing on prepended elements

I'm creating a site that generates a new Div for each search result. I include a checkmark and remove glyphicon on each search result, and want that search result to fade out when it's remove icon is clicked. For some reason my below code won't work. Any ideas? (The click function I'm referring to is the last one in the script)      var search = false;   $("#icon").click(function(){   $(this).addClass("animated fadeOut");   $(this).remove();   $("#helperText").addClass("animated fadeOut")   $("#helperText").remove();   $("#searchText").removeClass("hidden",5000, "easeOutElastic"); })  $("#searchText").submit(function(e){   if (search === true){     cleanUp();   }   e.preventDefault();   term = $("#input").val();   getData(term);   search = true; })  function divMaker(maker, data, i){   //pass in an array   jQuery('
', {     id: 'foo',     class: maker,     href: 'http://google.com',     title: 'Become a Googler',     rel: 'external',     html: "<button class='checkMark'></button>
"+data[1][i] + "

" + data[2][i]+"
<button class='remove'></button>", }).appendTo('#test'); }  function getData(term){   URL = "https://en.wikipedia.org/w/api.php?action=opensearch&format=json&search="+term;   $.ajax( {       url: URL,       data: 'queryData',       dataType: 'jsonp',       type: 'POST',       headers: { 'Api-User-Agent': 'Example/1.0' },       success: function(data) {             for (i=0; i < 5; i++){             maker = 'maker text-center animated bounceInUp';             divMaker(maker,data,i);             }       }   } ); }  function cleanUp(){   $("#test").empty(); }  $(".remove").on("click",function(){   $(this).addClass('animated fadeOut'); })