Prove by induction that all coins greater than or equal to 8 pence  can be made using 3 pence and 5 pence coins .  Here is my thought : I looked at Z+ greater than 8 ... I considered multiples of 3(equivalent to using 3p coins with repetitions) and considered multiples of 5. Rest of them were mostly primes where I had to combine both 3 and 5 .  And I noticed that 3 and 5 are in the form of 4k+1 and 4k-1.  I would appreciate any information . Thanks

How would I prove that for all elements of a set {n | n ∈ ℕ ∧ n > 7} (all natural numbers greater than 7), there are multiples of 3 and 5 which, when added up, are equal to that element of the set?  A := {n | n ∈ ℕ ∧ n > 7} ∀ n ∈ A: n = x*3 + y*5   I do understand why this is true:   8 = 1*3 + 1*5 9 = 3*3 + 0*5 ...  15 = 0*3 + 3*5   and this pattern repeats once 16 is reached, as 8 can be replaced with 1*3 + 1*5, so I'd basically have to add 1 to x and y for every time 8 fits in n.  I am however not sure how I can formulate this mathematically correct.  Thanks in advance, CrushedPixel


I just installed Ubuntu On my Lenovo ideapad s145 and I don’t see a WiFi icon or a WiFi setting what can I do to fix this And my pc doesn’t not have a space for an Ethernet cable and this is my OEM Wireless WiFi Card RTL88821CE 01AX710

My Laptop (HP Laptop 14-ck1xxx) came with the RTL8821CE Network Controller. When I run lspci | grep Network I get: 03:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8821CE 802.11ac PCIe Wireless Network Adapter  I‘m unable to get the Wi-Fi to work. What I did so far:  Download the repo at . Unzip the file and rename the folder from rtl8821ce-master to rtl8821ce. Run the following commands in the terminal:  cd Downloads/rtl8821ce/ sudo apt install bc module-assistant build-essential dkms sudo m-a prepare sudo ./dkms-install.sh    Everything seemed to install and execute successfully. Then, I rebooted my laptop and made sure secure boot is disabled. However, Ubuntu still displays: No Wi-Fi Adapter Found - make sure you have a Wi-Fi adapter plugged in and turned on  The command uname -r returns: 5.4.0-7634-generic  The command sudo lshw -C network returns: *-network                         description: Ethernet interface        product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:02:00.0        logical name: eno1        version: 15        serial: c4:65:16:08:52:bf        size: 1Gbit/s        capacity: 1Gbit/s        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation        configuration: autonegotiation=on broadcast=yes driver=r8169 duplex=full firmware=rtl8168h-2_0.0.2 02/26/15 ip=192.168.178.37 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s        resources: irq:16 ioport:4000(size=256) memory:a1204000-a1204fff memory:a1200000-a1203fff   *-network UNCLAIMED        description: Network controller        product: RTL8821CE 802.11ac PCIe Wireless Network Adapter        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:03:00.0        version: 00        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress cap_list        configuration: latency=0        resources: ioport:3000(size=256) memory:a1100000-a110ffff  What am I doing wrong? How can this be solved?


I have postfix on my box. All it should do is accepting all email and forwarding it somewhere else. I did it like so: main.cf: # (default config) virtual_alias_domains = domain.one domain.two virtual_alias_maps = regexp:/etc/postfix/virtual  virtual: /^admin@/ mail.one@example.org /^webmaster@/ mail.one@example.org /^security@/ mail.one@example.org  /@soptik.tech$/ mail.one@example.org /@prenoc.cz$/ mail.two@example.org  This works most of the time. But sometimes, the email gets undelivered. For example, I just donated to mozilla when I saw they had to lay off third of they workforce. But instead of an email, I received this: /var/log/mail.log (this seems to be most relevant line) Aug 11 20:38:59 junko postfix/smtp[13518]: 3D8A93F57B: to=<mail.one@example.org>, orig_to=<me@domain.one>, relay=mx1.seznam.cz[77.75.78.42]:25, delay=1.6, delays=0.43/0.01/1.1/0.16, dsn=5.7.1, status=bounced (host mx1.seznam.cz[77.75.78.42] said: 550 5.7.1 Sender Policy Framework of `bounce.e.mozilla.org' domain denied your IP address. (in reply to MAIL FROM command))  Why does it fail because of Sender Policy Framework? Forwarding works for almost all normal mails and lot of spam, but it seems to not work for Mozilla. I would thought that this will either work for everything, or nothing. Is there an issue with my configuration, or does the server I forward my mail to just failed to verify mozilla email? If so, can I, together with forwarding the mail, save it locally as well, just to be sure? Thanks.

I have a mail server "example.com" which forwards all emails with recipient "me@example.com" to "me@gmail.com". My mail server runs Postfix and it uses the virtual_alias_maps mechanism to perform the forwarding. I also have SPF records installed for "example.com":  v=spf1 a include:aspmx.googlemail.com ~all   The problem is, whenever someone delivers mail to "me@example.com", Gmail validates the example.com SPF records against example.com's IP address! I thought it's supposed to validate against the original sender's IP address.  For example, I'm on my laptop on my home Internet connection. I connect to example.com's mail server as follows:  $ telnet example.com 25 20 example.com ESMTP Postfix (Debian/GNU) HELO my-laptop.local 250 example.com MAIL FROM:<me@gmail.com> 250 2.1.0 Ok RCPT TO:<me@example.com> 250 2.1.5 Ok DATA 354 End data with <CR><LF>.<CR><LF> From: me@gmail.com To: me@example.com Subject: test  test . 250 2.0.0 Ok: queued as CE5F42200F9   Now when I open that mail in Gmail and view its source, I see the following headers:  Delivered-To: me@gmail.com Received: by 10.231.219.195 with SMTP id hv3csp61494ibb;         Sat, 14 Jul 2012 02:15:58 -0700 (PDT) Received: by 10.229.135.5 with SMTP id l5mr2360326qct.5.1342257358291;         Sat, 14 Jul 2012 02:15:58 -0700 (PDT) Return-Path: <me@gmail.com> Received: from example.com [EXAMPLE.COM's IP ADDRESS HERE]         by mx.google.com with ESMTP id u9si4262071qcv.89.2012.07.14.02.15.58;         Sat, 14 Jul 2012 02:15:58 -0700 (PDT) Received-SPF: neutral (google.com: [EXAMPLE.COM's IP ADDRESS HERE] is neither permitted nor denied by domain of me@gmail.com) client-ip=[EXAMPLE.COM's IP ADDRESS HERE]; Authentication-Results: mx.google.com; spf=neutral (google.com: [EXAMPLE.COM's IP ADDRESS HERE] is neither permitted nor denied by domain of me@gmail.com) smtp.mail=me@gmail.com Date: Sat, 14 Jul 2012 02:15:58 -0700 (PDT) Message-Id: <500138ce.c995e50a.6e4a.ffffd12aSMTPIN_ADDED@mx.google.com> Received: from my-laptop.local ([LAPTOP's IP ADDRESS HERE])     by example.com (Postfix) with SMTP id CE5F42200F9     for <me@example.com>; Sat, 14 Jul 2012 09:15:44 +0000 (UTC) From: me@gmail.com To: me@example.com Subject: test   As you can see in Received-SPF and Authentication-Results, the SPF records are being validated against [EXAMPLE.COM's IP ADDRESS] instead of [LAPTOP's IP ADDRESS].  Why does this happen, and how do I fix this problem?


I have a computer with a GF7050V-se mainboard but i get some beeps. There are 2 short beeps and 8-9-10 long beeps. Does anyone know what those beeps means?

Due to the amount of beep codes a PC can give, there are many questions on Super User about beep codes! I'm hoping this post will help to provide a community answer about all (dare I say all?) beep codes, with my fictional question.  When I try to turn my PC on, I hear some beeps. This is not beeping from the HDD or fan, but from the motherboard. Regardless of the number of beeps, what do the beeps mean?


When I am changing (on my debian box) to the root user with su, apparently the PATH is not correctly set. Some vital directories like usr/local/sbin are missing.  In /etc/profile I have the following lines (apparently standard default stuff not written by me):  if [ "`id -u`" -eq 0]; then     PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin/:/usr/bin:/sbin:/bin" else     PATH="/usr/local/bin:/usr/bin:/bin" fi export PATH   In /etc/login.defs I have (also default stuff):  ENV_SUPATH PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin   Why is my PATH not correctly set when I do su?

I have a user, say user1, which has modifications to its .bash_profile, one of them changing the PATH, e.g.: export PATH=/some/place:$PATH. This change works fine if I log on as user1 or do a su - user1.  But if I try to run a command via su as root, e.g.:  su -c test.sh oracle   (test contains echo $PATH)  It doesn't seem to have the modified PATH (or root's PATH, for that matter). I've also tried copying .bash_profile to .profile, to no avail.   Why is this happening?


While counting the degrees of freedom of a diatomic molecule, We neglect the rotation about the axis of the molecule stating the reason that it's energy is negligible. I agree with this reasoning, and have no questions about it.  But if we look at the derivation of the equipartition theorem (), then we see that any independent energy which is a quadratic function of momentum or position should have an energy of $\frac{1}{2}kT$.  But the above derivation never assumes that the energy should not be neglegible, or anything else of that sort. So according to the derivation, even the rotation about the axis of the molecule should have a energy of $\frac{1}{2}kT$.   So, why don't we count the rotation about the axis as a degree of freedom?

I was reading about the equipartition theorem and I got the following quotations from my books:  A diatomic molecule like oxygen can rotate about two different axes. But rotation about the axis down the length of the molecule doesn't count. - Daniel V. Schröder's Thermal Physics. A diatomic molecule can rotate like a top only about axes perpendicular to the line connecting the atoms but not about that line itself. - Resnick, Halliday, Walker s' Fundamentals of Physics.  Why is it so? Doesn't the rotation take place that way?


I upgraded to Ubuntu 18.04 yesterday, and my first boot was fine. I have a double partition Windows 10  - Ubuntu. After I restarted my PC I selected Ubuntu from GRUB, the loading screen appears, after more or less 3 seconds it started flickering with a period of around 2 seconds (1 sec black, 1 sec Ubuntu ). I waited about 10 minutes then restarted but the problem reappears.   So I restarted and ran in recovery mode.  After doing a fsck the system boots properly (with 800x600 resolution). If I restart it boots properly (in correct resolution) once. But if I shut down I need to fsck and restart each time.  I searched around and found that it may be a graphics driver related issue. I tried to update my drivers but under Additional Drivers in Software and Updates I can't find any available additional driver. Then I tried to update GRUB but still no results. I can't wipe out the disk; it would take hours to back up all important data.  Additional info:  $ sudo lshw -C video [sudo] password di lollouno:    *-display                         description: VGA compatible controller        product: Carrizo        vendor: Advanced Micro Devices, Inc. [AMD/ATI]        physical id: 1        bus info: pci@0000:00:01.0        version: ca        width: 64 bits        clock: 33MHz        capabilities: pm pciexpress msi vga_controller bus_master cap_list rom        configuration: driver=amdgpu latency=0        resources: irq:40 memory:d0000000-dfffffff memory:f0000000-f07fffff ioport:f000(size=256) memory:feb00000-feb3ffff memory:c0000-dffff   Update:   Today I was able to boot. It took about 10 minutes, so finally I am not sure if yesterday it really was impossible to boot or if I did not wait enough.   Anyway help would be appreciated to speed up boot

As mentioned in the title. Was upgrading from 17.10. Having this screen flickering.  My GPU is AMD RX480  What I did:   Search for similar issues for 18.04, can't find any Perform fresh install. Still the same.   Please help. It is very annoying. I can't work.


I have traditionally used proprietary software tools for tiling raster datasets but I am keen to explore the open source solutions as well.    Are there any open source solutions that can easily tile a GeoTIFF into smaller GeoTIFF (not png or jpg tiles) where you can set the dimensions yourself?   From what I have seen in QGIS, GDAL this is not as flexible as I hoped whilst Saga shows some promise.

I have an image of size 1GB (.tif), with the width and height 94000x71680. I would like to chunk this image into 20000X20000 tiles so that I can process them.   How can I do this?


The basis of Quantum Mechanics is contained in the postulates which tell us how to describe quantum systems (below I disconsider possibly degenerate spectra just for simplicity):   To describe a quantum system there is a Hilbert Space $\mathcal{H}$ whose elements represent the possible states of the system. For each physical quantity associated to a system there is one hermitian operator defined on $\mathcal{H}$. We call these operators observables. The only possible values to be measured of an observable are the elements of its spectrum. If $A$ is an observable with discrete spectrum $\sigma(A)=\{a_i : i \in \Bbb N\}$, then the probability of measuring $a_i$ on the state $|\psi\rangle$ is $P(a_i)=|\langle \varphi_i|\psi\rangle|^2$, where $|\varphi_i\rangle$ is the eigenstate corresponding to the eigenvalue $a_i$. Analogously, if $A$ is an observable with continuous spectrum $\sigma(A)$ then the probability density for the values of $A$ on the state $|\psi\rangle$ is $\rho(x)=|\langle x|\psi \rangle|^2$ where $x\in \sigma(A)$ and $|x\rangle$ is the generalized eigenvector corresponding to $x$. When one performs a measurement of the observable $A$ the state colapses to the eigenstate corresponding to the eigenvalue measured. The time evolution is governed by the requirement that the observable corresponding to the energy is the generator of time translations. That is, the time evolution equation is $i\hbar \frac{d|\psi\rangle}{dt}=H|\psi\rangle$.   Everything else follows from this. If we want to describe also spin we include Pauli's postulates and again, everything works just fine.  Now, apart from Quantum Mechanics there is Quantum Field Theory. I'm just starting to study it and there is something I still didn't get: Quantum Field Theory is just one application of Quantum Mechanics or it modifies Quantum Mechanics?  In other words, is QFT just one application of these postulates I've stated, or it modifies these postulates somehow? And if it does, how does QFT modifies Quantum Mechanics and its postulates?

As I understand it, quantum mechanics for particles was developed to replace classical mechanics for particles. In essence, we realized that particle cannot be given an exact place and momentum but must be described using probabilities and more specifically wave functions.   Is quantizing a field the same idea? That is, suppose I am considering an electric field $\mathbf E(\mathbf x,t)$. Does quantizing a field mean that we no longer believe the field can have a definite value at points in spacetime? Does this mean we are looking to find a wave function analogue for fields?


I am learning topology and am struggling with some of the concepts of open sets regarding subspaces.  The problem I am working on says, that Y is a subspace of X, and A is a subset of Y, then show that the topology A inherits as a subspace of Y is the same topology it inherits as a subspace from X.  now what I am trying to prove is that A is a basis for the subspace topology of Y of X, and A is the basis for the subspace topology on X, then these two topologies are the same.  Here is the lemma I am struggling to utilize , it says, "Let Y be a subspace of X, if U is open in Y and Y is open in X, then U is open in X."  Since A is a subset of Y, does this imply that A is open in Y? (i think so). Y is open in X, so does this imply that A is open in X? (I think so)  If A is open in Y, and A is open in X, does this mean that A is open in $Y \bigcap U$ for $U \subset X$ ?  (This I am not sure of).  Further, assuming my intuition is right,  if A is open in $Y \bigcap U$ does this mean for $x \in Y \bigcap U$ that $x \in A \bigcap U$ since A is open in both Y and X?    this yields my needed argument saying that $A \bigcap U \subset Y \bigcap U$  this can then be shown that $\mathbb{B}_{A}$ is a basis for both topologies. my question is that just because A is a subset of Y and A is open in X, and $x \in Y \bigcap U$ , I am not sure if this implies that $x \in A \bigcap U$.  Thank you again so very much and I will greatly appreciate any clarification.

Show that if $Y$ is a subspace of $X$, and $A$ is a subset of $Y$, then the topology $A$ inherits as a subspace of $Y$ is the same as the topology it inherits as a subspace of $X$.  First some notational specifications: Let us define $\tau$ as the topology of $X$ $\tau_{Y}=\{U \cap Y; U \in \tau \}$; $\tau_{A}^Y=\{V \cap A; V \in \tau_{Y} \}$ and $\tau_{A}^X=\{U \cap A; U \in \tau \}$  Let us show that $\tau_{A}^Y=\tau_{A}^X$  $\subset$: Let $V \cap A$ be an element of $\tau_{A}^Y$ such that $V \in \tau_{Y}$  Then, there exists $U\in \tau$ such that $V=U\cap Y$  $V\cap A=(U\cap Y)\cap A=U\cap (Y\cap A)= U\cap A$  Hence: $V\cap A \in \tau_{A}^X$ and so: $\tau_{A}^Y \subset \tau_{A}^X$  $\supset$: Let $U \cap A \in \tau_{A}^X$  $U\in \tau \iff U \text{ open in } X$   But $U \cap Y$ open in $Y \iff U \cap Y \in \tau_{Y}$  Hence $(U \cap Y) \cap A \in \tau_{A}^Y$ since $U \cap Y \in \tau_{Y}$  Therefore $U \cap A \in \tau_{A}^Y$  Hence: $\tau_{A}^X \subset \tau_{A}^Y$  Therefore: $\tau_{A}^Y=\tau_{A}^X$


I just would like to know the reason why a question I formulated was down voted.

Note: If you're looking for a simple explanation as to why comments aren't required on downvotes, see .   I used to get "upset" (though that is too strong a term) when I got downvoted without comment. If my answer isn't good enough then I'd like to know why. Not only does it improve the answer for the OP but it improves my knowledge too.  Where the down-vote has been explained I've found it useful & it has improved my answer, or forced me to delete the answer if it was totally wrong.  So is there any way we can encourage people to leave a comment? Perhaps they don't lose rep if they explain their down-vote?  I must admit though that I haven't always explained my down-vote either so you could call me a hypocrite. I've also grown a thicker skin over the months of using SO (it seems to have come with the higher rep score ;-)), so I'm less bothered about this now.


Sometimes we use spend like "spend something on doing something" but sometimes we are using without on like "I spend a lot of time working on  this project". Is there any difference between these usages? If yes, what is the difference?  Thank you for your help.

Which is correct?     The average time spent on reading in my country is disappointing.   Or      The average time spent reading in my country is disappointing   Generally for this sentence, do we need a preposition? Is "on" correct here, or might it be "in"?


I recently created a partition on my HP Pavilon laptop with an Ubuntu version on it. But now when I start the laptop first the HP logo appears and then it boots straight into Windows 10 without showing grub. I am able to press F9 and then boot straight from there into "ubuntu" which leads me to grub from where I can choose either to boot into windows or into Ubuntu. I am also able to boot into grub (and thus into Ubuntu) via "advanced setup options" when I'm on windows. Nevertheless I would like to have grub immediately show up on any startup of the laptop (not booting directely into either operating system).

I installed Ubuntu on a Dell XPS 13 laptop that had Windows 10 preinstalled on it. I installed it from a USB flash drive on a partition. When I boot my computer I can only boot into Windows 10 and Ubuntu is nowhere to be seen.  If I boot into my USB then I can see that Ubuntu is installed, but I can't get to it from the BIOS boot menu.


I have this code - which works perfectly when pages aren't lazy loaded with AJAX.  As soon as AJAX gets involved it doesn't work at all until the page is refreshed.  omShortcodes.modules.toggle = { init: function() {      jQuery('.omsc-accordion .omsc-toggle').addClass('omsc-in-accordion').find('.omsc-toggle-title').click(function(){          var $toggle=jQuery(this).parent();          if($toggle.hasClass('omsc-expanded')) {             $toggle.removeClass('omsc-expanded');             $toggle.find('.omsc-toggle-inner').slideUp(300);             return false;         }          var $acc=$toggle.parents('.omsc-accordion');         if(!$acc.hasClass('omsc-multiopen'))             $acc.find('.omsc-toggle.omsc-expanded').removeClass('omsc-expanded').find('.omsc-toggle-inner').slideUp(300);          $toggle.find('.omsc-toggle-inner').slideDown(300,function(){             var h=jQuery(this).parent().height();             var pos=jQuery(this).parent().find('.omsc-toggle-title').offset();             var scroll=jQuery(window).scrollTop();             var wh=jQuery(window).height();             if(pos.top < scroll || (pos.top > scroll && pos.top+h > scroll+wh))                 jQuery('html,body').animate({ scrollTop: pos.top+'px' }, 200);         }).find('iframe[src*="maps.google"]').each(function(){             jQuery(this).attr('src',jQuery(this).attr('src'));         });         $toggle.addClass('omsc-expanded');      });      jQuery('.omsc-toggle').not('.in-accordion').find('.omsc-toggle-title').click(function(){          var $toggle=jQuery(this).parent();          var $inner=$toggle.find('.omsc-toggle-inner');         if(!$inner.length)             return false;         if($inner.is(':animated'))             return false;          $toggle.toggleClass('omsc-expanded');         $inner.slideToggle(300);         if($toggle.hasClass('omsc-expanded')) {             $inner.find('iframe[src*="maps.google"]').each(function(){                 jQuery(this).attr('src',jQuery(this).attr('src'));             });         }          return false;     });  } }   Is there another way of handling this to be able to work properly with AJAX?

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


Update: They fixed the macOS wifi lag on Synergy 1.9.0!   I'm not sure why this started happening. I just started using Synergy again to control my laptop using my desktop's keyboard and mouse, and the cursor (when accessing my laptop) is incredibly laggy, jumpy, etc. (and it wasn't like this before). Any ideas on how this can be fixed?

Update: They fixed the macOS wifi lag on Synergy 1.9.0!   I’m using  and using a Windows 7-Desktop as the server and a Kubuntu-Laptop as client.  My laptop is connected to my router via WLAN and my desktop is connected via cable. I have no idea what to do since it worked fine first, but for a couple of weeks now the mouse and keyboard are unbearably laggy on the client, to the point where I can barely use them.


my input is:    blah blah blah 1 blah blah blah 2  and I want my regex to match this  xxxx pattern  and the desired output is 1.somenumber 2.xxxx  I wrote a naive solution which could cover   blah blah blah 1   blah blah blah 2 notice: they are on different lines  the output is : 18, blah blah blah 1 and 19,blah blah blah 2   but when the input is  blah blah blah 1 blah blah blah 2 which is on the same line  my output is 18,  blah blah blah 1 blah blah blah 2  how could I bypass this problem?  Update:  regex: /\(.*)<\/span>/ig  testinput:  case1 -> two lines of code  often graces doorways tied into ropes called  often graces doorways tied into ropes called ristras.            case2 -> one line of code  often graces doorways tied into ropes calledoften graces doorways tied into ropes called ristras.  Update2:  This is not a dom , it is just a plain text that I want to process.  Update3: so my problem about Regex is solved, now I have a question about comparing the proessing speed between regex or dom operation ? how could implement such a test ?

It seems like every question on stackoverflow where the asker is using regex to grab some information from HTML will inevitably have an "answer" that says not to use regex to parse HTML.  Why not? I'm aware that there are quote-unquote "real" HTML parsers out there like , and I'm sure they're powerful and useful, but if you're just doing something simple, quick, or dirty, then why bother using something so complicated when a few regex statements will work just fine?  Moreover, is there just something fundamental that I don't understand about regex that makes them a bad choice for parsing in general?


I would like to recreate something like this using blender, if someone knows please explain it to me.  thanks in advice.

How to create the outer nodes effect in Blender Cycles, including the lines? I know this is achieved using a particle system, but don't know how.   Also can anybody suggest any plugins for blender that does the same?


I am wondering whether there is any screen mirroring software that will work with my non-rooted Android phone using 4.4.2.

I have an Android phone running 5.0 (CM12) that has "cast screen" on the quick settings page, but no devices are listed. I don't own a Chromecast, but I have an Ubuntu HTPC running 14.04 and Kodi.  What can I do to make the HTPC a receiver and show up on the network?


I'm mapping areas in QGIS 2.12 based on average pricing, using area polygons (PostGIS) joined with a CSV data table that doesn't have values for areas that didn't have any sales.   I'd like to color the areas that don't have matching "area" values in my data table, but also use a green to red ramp on the areas that do have pricing.  My data is set up like this:   area, avgprice, sales A, 50000, 100 B, 100000, 50 C, NULL, NULL D, 250000,  20 etc.   I was able to set up a zero value with white as the coloring, and 5 other colors encompassing the total average price range, but I can't seem to Classify NULL as a value to use in the color ramp.   Maybe there is a way to use a categorized style, but I don't if there is a way to set value ranges instead of distinct values for that methodology.

I have a polygon feature dataset, and an attribute from a different table that I join (one-to-one) within QGIS in order to symbolise the attributes as a choropleth map. However, not all polygon fields have a matching field in the table of numerical attributes, so there are some null values when producing the graduated symbology.  From my research, the most common piece of advice in this situation is to include a copy of the polygon dataset (or some other background) that defines a default symbology. This works because the null values are not classified in the graduated symbology, so one can see "underneath" them. I have attached an image of exactly this. The dark grey features do not exist in the join table (mb_percentile_isochrones_all), but do exist in the boundary polygons table (mb2013_wgtn). So I need two instances of the mb2013_wgtn table in order to show the "no data" features.    However, this does not seem elegant to me. Much more intuitive would be to define a null value symbol. Perhaps this could be perfectly transparent to be consistent with what currently exists, or perhaps it would be some kind of muted grey—whatever the user wants. The point is, at present one needs two different layers in the contents in order to handle the symbology of null values. This means that to change the symbology of all your features at the same time (say, if you want to increase the width of all borders), this has to be handled twice: once in the properties for the feature with the graduated symbology, and once for the "background" layer that handles the null symbol.  Is it possible to define a "null" value symbol without using a "copy" of the same layer used for the graduated symbology, in QGIS (2.6.1)?


How can I tell *tex commands from TeX Live 2013 that they should stop and exit when they detect an error instead of opening a command prompt?

In case of a syntax error, pdflatex usually (in \errorstopmode) gets interactive and asks you what to do. I know I can press:   X to terminate S to enter \scrollmode (continue processing without stopping if further syntax errors arise, but stop for other errors) R to enter \nonstopmode (continue processing without stopping if further errors arise) Q to enter \batchmode (continue processing without stopping if further errors arise and suppress further output to the terminal)   Apparently, only the latter three (SRQ) can be provided implicitly by the respecive \...mode commands or the -interaction=...mode command line option. However, what I need is a mode that mimics the implicit pressing of X, that is, to make the pdflatex process terminate after the first error.


Let's consider a system described by this simple equation:  $x^{2}+y^{2}=5$  this represents a holonomic constraint. Suppose I would like to reduce the degrees of freedom of this system, I should be able to do it since is described by a holonomic constraint. However, both $x^{2}$ and $y^{2}$ are not invertible. So how can I write one of them as a function of the other?

I'm trying to understand how it's possible to always reduce the degrees of freedom of a system represented by $n$ coordinates $q_{i}$ for which holds $f(q_{1},...,q_{n})=0.$  For example, let's consider the system represented by $x+\cos y=5$. How can i show that this system has only 1 degree of freedom?


I've been searching for a long time but didn't find an answer for my question, can tell me what the meaning of  (?:[-\w\d{1-3}]+\.)+   and not   (?:[-\w\d{1,3}]+\.)+   I don't understand the {1-3} part and can't find anywhere what it's mean. Thank you

What is the use of the yield keyword in Python? What does it do? For example, I'm trying to understand this code1: def _get_child_candidates(self, distance, min_dist, max_dist):     if self._leftchild and distance - max_dist < self._median:         yield self._leftchild     if self._rightchild and distance + max_dist >= self._median:         yield self._rightchild    And this is the caller: result, candidates = [], [self] while candidates:     node = candidates.pop()     distance = node._get_dist(obj)     if distance <= max_dist and distance >= min_dist:         result.extend(node._values)     candidates.extend(node._get_child_candidates(distance, min_dist, max_dist)) return result  What happens when the method _get_child_candidates is called? Is a list returned? A single element? Is it called again? When will subsequent calls stop?   1. This piece of code was written by Jochen Schulz (jrschulz), who made a great Python library for metric spaces. This is the link to the complete source: [Module mspace][1].


I'm using Ubuntu 12.04 and installed the Conky system monitor, and start it with the conky command. I added this code on startup-applications but nothing works. How do I start conky when my Ubuntu starts up? Is it possible to start multiple Conky themes on startup?

I frequently need to start several programs that I use every time I start my computer. How can I make it so that whenever I login the program is automatically launched?


In a bash shell (A), typing an ` (accent-grave) will start another shell prompt (B). The output of any command entered in B is a command for A.   $ ` > whoami` -bash: Joe: command not found   (If my username were Joe.)   $ man ` > ` What manual page do you want?   Is there a man page for this, preferably with some examples?

I came across the following command:  sudo chown `id -u` /somedir   and I wonder: what is the meaning of the ` symbol. I noticed for instance that while the command above works well, the one below does not:  sudo chown 'id -u' /somedir


Let $f\in L^p(X)$ and $1/p+1/q=1$. Show that $\|f\|_{p}=\sup\left\{ \left|\int_{X}fg\right\|:g\in L^q(X),\|g\|_{q}\leq 1\right\}$ Hi. I'm stuck proving that $\|f\|_{p}$ is the lowest upper bound. I have only is upper bound because $\|fg\|_{1}\leq \|f\|_{p}\|g\|_{q}\leq \|f\|_{p}$ by Holder's Theorem, and $\left\|\int_{X} fg\right\|\leq \|fg\|_{1}\leq \|f\|_{p}$ but, why $\|f\|_{p}$ is the lowest upper bound?$}

Show that    $$\|f\|_{L^{p}}=\sup\bigg\{\bigg|\int_{{\bf R}^{n}}f(x)g(x)~dx\bigg|:\|g\|_{L^{q}}\le1\bigg\}=\sup\bigg\{\int_{{\bf R}^{n}}|f(x)g(x)|~dx:\|g\|_{L^{q}}\le1\bigg\}$$   provided that $f\in L^{p}({\bf R}^{n})$ for each $1\le p\le\infty$ and $\frac{1}{p}+\frac{1}{q}=1$   Here is my working :  For each $1\le p\le \infty~$,one has by Hölder's inequality that   $$\bigg|\int_{{\bf R}^{n}}f(x)g(x)~dx\bigg|\le\int_{{\bf R}^{n}}|f(x)g(x)|~dx\le\|f\|_{L^p}\|g\|_{L^q}$$    and hence that   $$\sup\bigg\{\bigg|\int_{{\bf R}^{n}}f(x)g(x)~dx\bigg|:\|g\|_{L^{q}}\le1\bigg\}\le\sup\bigg\{\int_{{\bf R}^{n}}|f(x)g(x)|~dx:\|g\|_{L^{q}}\le1\bigg\}\le \|f\|_{L^{p}}$$  Conversely, we may assume $f\ne0$ a.e. on ${\bf R}^{n}$ otherwise, our result holds easily.Next , we will proceed by discussing three following cases.  Before start , we define $\ sgn(f)=f\cdot|f|^{-1}$ if $f\ne0$ and  $\ sgn(f)=0$ if $f=0 ,$ keep in mind that here $f$ may be complex-valued.  Case i) : Consider$~~p=1$.  Thus $q=\infty$ and take $g=\overline{\ sgn(f)} $ and then $|g|=1$ a.e. on ${{\bf R}^{n}}$, so , $\|g\|_{L^{\infty}}=1$ on ${{\bf R}^{n}}$.  So,  $$\|f\|_{L^{1}}=\int_{{\bf R}^{n}}|f(x)|~dx=\int_{{\bf R}^{n}}f(x)g(x)~dx$$  Therefore , $$\|f\|_{L^{1}}\le \sup\bigg\{\bigg|\int_{{\bf R}^{n}}f(x)g(x)~dx\bigg|:\|g\|_{L^{\infty}}\le1\bigg\}\le\sup\bigg\{\int_{{\bf R}^{n}}|f(x)g(x)|~dx:\|g\|_{L^{\infty}}\le1\bigg\}.$$  Case ii) : Consider $1<p<\infty.$   Observe that $$fh=f\cdot|f|^{p-1}\overline{\ sgn(f)}=|f|^{p}=|h|^{q}$$  ,where $h = |f|^{p-1}\overline{\ sgn(f)}$ and $\frac{1}{p}+\frac{1}{q}=1.$ But then , $h\in L^{q}$ and obtain $\|h\|_{L^{q}}=\|f\|_{L^{p}}^{\frac{p}{q}}~.$   Let $g=h/\|h\|_{L^{q}}$ so that $\|g\|_{L^{q}}=1$ and we have   $$\int_{{\bf R}^{n}}f(x)g(x)~dx=\int_{{\bf R}^{n}}|f(x)g(x)|~dx=\int_{{\bf R}^{n}} \frac{|f(x)h(x)|}{\|f\|_{L^{p}}^{p/q}}=\frac{\|f\|_{L^{p}}^{p}}{\|f\|_{L^{p}}^{p/q}}=\|f\|_{L^{p}}$$  Therefore,   $$\|f\|_{L^{p}}\le\sup\bigg\{\bigg|\int_{{\bf R}^{n}}f(x)g(x)~dx\bigg|:\|g\|_{L^{q}}\le1\bigg\}\le\sup\bigg\{\int_{{\bf R}^{n}}|f(x)g(x)|~dx:\|g\|_{L^{q}}\le1\bigg\}$$  Case iii) : Consider $p=\infty$  For every $k\in {\mathbb{N_{>0}}}$ , define $E_{k}=\bigg\{x\in {{\bf R}^{n}} : |f(x)|>\|f\|_{L^{\infty}}-\frac{1}{k}\bigg\}$ . Then each $|E_{k}|>0$ since by the very definition of essential supremum $\|f\|_{L^{\infty}}~.$  Furthermore, for every $k\in\mathbb{N_{>0}}$ we let $g_{k}=\frac{1}{|A_{k}~|}\chi_{A_{k}}\overline{\ sgn(f)}$, where $A_{k}$ is measurable subset of $E_{k}$ such that $0<|A_{k}|<\infty$.The existence of $|A_{k}|$  assures by $A_{k}=E_{k}\cap B(0,R)$ for some sufficiently large $R>0$.  Then  $$\|g_{k}\|_{L^{1}}=\int_{{\bf R}^{n}}|g_{k}(x)|~dx=\int_{A_{k}}\frac{1}{|A_{k}|} ~dx=1$$ and   $$\int_{{\bf R}^{n}}|f(x)g_{k}(x)|~dx=\int_{{\bf R}^{n}}|f(x)||\frac{|\chi_{A_{k}}(x)\overline{\ sgn(f(x))}|}{|A_{k}|}dx=\int_{A_{k}}\frac{|f(x)|}{|A_{k}|}dx\le\|f\|_{L^{\infty}}<\infty.$$  Therefore, for each $k\in\mathbb{N_{>0}}$ , we have  \begin{align} \bigg|\int_{{\bf R}^{n}}f(x)g_{k}(x)~dx~\bigg|&\ge\int_{{\bf R}^{n}}f(x)g_{k}(x)~dx\\ &=\int_{{\bf R}^{n}}\frac{f(x)}{|A_{k}|}\chi_{A_{k}}(x)\overline{\ sgn(f(x))}~dx\\ &=\int_{A_{k}}\frac{|f(x)|}{|A_{k}|}~dx\\ &\ge\|f\|_{L^{\infty}}-\frac{1}{k} \end{align}  Consequently,  $$\sup\bigg\{\int_{{\bf R}^{n}}|f(x)g(x)|~dx:\|g\|_{L^{1}}\le1\bigg\}\ge\sup\bigg\{\bigg|\int_{{\bf R}^{n}}f(x)g(x)~dx\bigg|:\|g\|_{L^{1}}\le1\bigg\}\ge \|f\|_{L^{\infty}}-\frac{1}{k}$$  Whence , our conclusion follows if we take $k\longrightarrow \infty.$  If you have the time , please checking the proof for validity, or , just ignore it that is okay. Any valuable suggestion will be appreciated . Thanks for your patiently reading and considering my request.


4 Answers   Like this one for example...      the answer should just be removed.

Many times I've run into questions on SO that have a wrong answer accepted.   (Example:  (Note: The accepted answer has been edited to include the caveat .))  After trying to convince others, you realize that the person who asked the question got an answer they deemed correct and stopped looking after that. Even if there is a correct answer, it gets buried somewhere deep in the list, because nobody bothers to look at questions with an accepted answer.  Should I, as a high-rep user, use his powers to fix this? How would I go about this? Edit the original question? Edit the answer that got accepted to make it right?  Or just let it be? Internet is a jungle anyway.


Examples:   Thanks for painting my pub sign, but could you increase the size of the spaces between Bull and "and" and "and" and Bush? All the faith he had had had had no effect on the outcome of his life.   Longest or most interesting one you know of?  Punctuation between the words is allowed, but it must be a single valid sentence.

What are some examples of awkward sounding but grammatically correct sentences?


I'm beginner on linux SO, before I was on Windows SO...  In windows I downloaded a program and then run *.exe file, and ready !  In linux, I downloaded this file , but I have not idea how to start this program.  Does it exist some program to install this, or e.g commands rules.  any idea ?

I have downloaded tar.gz files. But I don't know how to install it. How do I install this kind of file?


The base case $n=1$:  $B\cup\left(\bigcap_{i=1}^1A_i\right)=B\cup A_1$   and   $\bigcap_{i=1}^1(B\cup A_i)=B\cup A_1$.  Now, suppose inductively that $B\cup\left(\bigcap_{i=1}^nA_i\right)=\bigcap_{i=1}^n(B\cup A_i)$. Then  \begin{align*} B\cup\left(\bigcap_{i=1}^{n+1}A_i\right) &= B\cup \left[\left(\bigcap_{i=1}^nA_i\right)\cap A_{n+1}\right] \\ &= \left[B\cup\left(\bigcap_{i=1}^nA_i\right) \right]\cap\left(B\cap A_{n+1}\right) \\ \end{align*}  I am stuck at this point of the induction process, could someone please assist me.

$\displaystyle B\cup (\bigcap_{i=1}^n A_i)=\bigcap_{i=1}^n (B\cup A_i)$  I was able to prove this without using induction, however I am supposed to prove it using induction. How should I go about doing so?


To increase the ADC resolution, oversampling technique can be used which must be followed by decimation (average) method. Oversampling is just take several samples within time period. Unlike the normal averaging in which you might lose all the extra bits from oversampling, Decimation can remove only the lowest of low bits leaving some of the higher low bit to contribute to final result.  What is the lowest and higher low bit? And why the lowest low bit usually most noisy than the rest of the bits?  From my understanding is that the higher the extra bit can we get, a better ADC resolution can we have. In this case why can't we just use oversampling without decimation? For example, a summation of 16 10-bit ADC result in 14-bit ADC and when we use decimation method (divide by 4) result in 12-bit resolution.   So why can't we just use oversampling and gain 14-bit resolution instead of 12-bit resolution with decimation? Is that  to reduce the noise after the oversampling stage?

To increase the 12-bit resolution of ADC from 12 bit to 14 bit, this can be done through the 'oversampling and decimation method'. An  says that  The higher the number of samples averaged is, the more selective the low-pass filter will be, and the better the interpolation. The extra samples, m, achieved by oversampling the signal are added, just as in normal averaging, but the result are not divided by m as in normal averaging. Instead the result is right shifted by n, where n is the desired extra bit of resolution, to scale the answer correctly. Right shifting a binary number once is equal to dividing the binary number by a factor of 2. It is important to remember that normal averaging does not increase the resolution of the conversion. Decimation, or Interpolation, is the averaging method, which combined with oversampling, which increases the resolution  This reference clearly says that for the decimation method, the result is right shifted by the desired extra bit of resolution, and not divided by m as in the normal average.  So, the question is, why do we need to use the decimation method instead of the normal averaging after the oversampling to increase the ADC resolution?  It says above "Right shifting a binary number once is equal to dividing the binary number by a factor of 2", but what if we don't use a binary number? How do we use the decimation method in this case?


I have learnt that at room temperature there are some free electron(not bound to any nucleas) in a conductor and when an electric field is applied they form an electric current.I am quite comfortable with this theory but then I am introduced to band theory which talks of valence and conduction band and they write when electrons can jump from valence to conduction band they conduct electricity.I cannot get what these bands are and why that jump causes current flow?I think the energy level of the valence electrons of all the atoms in the crystal form valence band(correct me,if wrong) but I have no idea about conduction band.Is it allowed energy levels of free electrons present in the crystal or something else?Please clarify

The often told cause of conductor conducting electricity is their valence band and conduction band overlap and when an electric field is applied the electrons jumps into conduction band and electricity flows.I don' t get this how the jump of electrons from valence band to conduction band i.e,the next available energy band cause current to flow.I learnt electrodynamics using free electron sea model and now I am unable to harmonise the two.For example, Suppose we have sodium crystal which is a conductor.The valence band in this case will be the one due to 3s and conduction band  3p.How can a jump from 3s to 3p cause current flow?


Here's a piece of code from my project software:  def fun_1(self, i):     print("")     print("Welcome to Option 1: View Passwords")     while True:         print("")         which_o1 = input("1: Input a New Account details \n2: Exit \nPlease Input the option number: ")          if which_o1 == str(1):             with open(str(i)+'.txt', 'a+') as file:                 while True:                     print("")                     web_n = input("Please Input Website name: ")                     print("")                     e_u = input("Please input email/username: ")                     print("")                     pass_w = input("Please input password: ")                      while True:                         print("")                         sure = input("Website- " +web_n+"\nEmail/Username- "+e_u+"\nPassword- "+pass_w+"\nAre You sure about these details? Yes/No: ")                          if (sure.lower()[0]) != 'y' and (sure.lower()[0]) != 'n':                             print("")                             print("Please input a valid response Yes/No!")                             continue                          elif (sure.lower()[0]) == 'y' and (sure.lower()[0]) != 'n':                             list_log = [web_n, e_u, pass_w]                             file.write(str(list_log) + '\n')                             break                             break                             continue                          elif (sure.lower()[0]) == 'n' and (sure.lower()[0]) != 'y':                             break                             continue          elif which_o1 == str(2):             return (i)         else:             print("")             print("Please Enter a Valid Response!")             continue   So has you can see that it has 3 while True loop. The problem is occurring while breaking and looping the loop.  If you see the latest While True under "pass_w" in the middle elif, where it says elif (sure.lower()[0]) == 'y' and (sure.lower()[0]) != 'n':, in it I have 2 break and 1 continue because what I wanted to do is that when that elif executes it just break middle 3rd while true, 2nd while true and continue means loop the first while true at the start of the code, but it just keep looping 3rd While True in the middle of the code instead of breaking it.  Is there a way I can make it possible?

Given the following code (that doesn't work):  while True:     #snip: print out current state     while True:         ok = get_input("Is this ok? (y/n)")         if ok.lower() == "y": break 2 #this doesn't work :(         if ok.lower() == "n": break     #do more processing with menus and stuff   Is there a way to make this work? Or do I have do one check to break out of the input loop, then another, more limited, check in the outside loop to break out all together if the user is satisfied?


I loved the edit function in Shutter on Ubuntu 16.04/17.04/17.10 but now in 18.04 it says libgoo-canvas-perl needs to be installed - which is not available in 18.04.  Is there a PPA or how can I fix this?

I am trying to enable the Edit button in Shutter. I installed the application from Ubuntu Software and are using Ubuntu 18.04.  After taking a screenshot the Edit button is disabled. And when hovering the mouse pointer over the button the text "Goo::Canvas/libgoo-canvas-perl needs to be installed for this feature" is shown.    I have tried to install the package libgoocanvas2-perl and restarted the computer, but the edit button is still not enabled:  sudo apt install libgoocanvas2-perl   That is the only package I can find.  Anyone that knows how to fix this?


I flagged  because I mis-read it and thought it was a thank-you answer and not a real one. I know my flag will be rejected and rightly so, but I wish I could have retracted it myself. The close-vote pop-up allows retraction, I request the flagging pop-up be given the same feature.

I'm wondering (since it just happened to me), is it possible to "cancel" ("undo", "delete", "retract", whatever) a flag I just raised if I misclicked it, so the mods won't waste time?  I looked everywhere, but I can't find such a feature.


I have tried most of the suggestion given by google but I am disappointed. Still my error_log file keep increasing by unbelievable size.  I have done following exercise:   sudo systemctl disable cups-browsed sudo service avahi-daemon stop avahi-browse -a | grep Printer sudo cupsctl --no-share-printers   Also in /etc/cups/cupsd.conf (making "browsing=off") and  /etc/cups/cups-browsed.conf (making "browsing protocol=none")  Even I have tried to put it in logrotate:  cat /etc/logrotate.d/cups      /var/log/cups/error_log {     daily     missingok     rotate 7     sharedscripts     postrotate              if [ -e /var/run/cups/cupsd.pid ]; then                       invoke-rc.d --quiet cups force-reload > /dev/null                       sleep 10              fi     endscript     compress     notifempty     create 640 root lpadmin     }   error_log :  E [02/Sep/2016:13:45:31 +0530] File "/usr/lib/cups/notifier/dbus" has insecure permissions (0100757/uid=0/gid=0).      [only this error fills up whole memory !]  Nothing is working.

A few days ago I realized my Ubuntu machine wouldn't load after login. After some digging around on a liveCD I realized my HDD was at 100% capacity, so I deleted some large files and was able to log in. I didn't have sudo permissions any more and had to boot into recovery mode and change the sodoers file, but eventually recovered root permissions.   I then noticed my machine was a little sluggish, and top was showing cupsd using 100% CPU. I've never seen this program before but I soon realized it was a legitimate program.   I the deleted about 40GB worth of videos, only to see my drive space deplete almost instantly in front of my eyes. With a little research and intuition, I realized it might be a a log file being blown up, and sure enough ls -lh /var/log/cups/ shown me an error_log file that was 80GB+ large.   I deleted the file sudo rm -rf /var/log/cups/error_log, killed the service with sudo service cups end, and went on my business. I realized after that it would have been a good idea to check out the contents of error_log before I deleted it, but I wanted to get rid of the thing before I was locked out again.  That was yesterday. Today, I started my laptop again and saw cupsd running again at 100% cpu, and sure enough I see my disk space depleting. I stopped the service and run tail -f /var/log/cups/error_log, and there are millions of lines of this:  W [15/Jul/2015:11:23:03 -0700] Notifier for subscription 911 (dbus://) went away, retrying! E [15/Jul/2015:11:23:03 -0700] File "/usr/lib/cups/notifier/dbus" has insecure permissions (0100777/uid=0/gid=0).   ==EDIT=================================================================  ls -l /usr/lib/cups/notifier/dbus shows permissions and ownership as -rwxrwxrwx 1 root root when they should be -rwxr-xr-x 1 daemon root, as described in the comments. sudo chown root:root /usr/lib/cups/notifier/dbus also did not fix the ownership problems.   Finally I removed and reinstalled cups, but to no avail. These links were given as potentially helpful guides,(,) but they ultimately result in suggesting a reinstall of the OS itself.


Is there a way to move the launcher to the right side of the screen in 14.04? everything that pops up in searches is only for moving to the bottom.

I can’t get used to the new Unity system. I’d like to move the left Unity panel to the bottom of screen (like Windows 7 – more similar is better).  But I can't find a way. Is it possible?


I'm a newbie with tcpdump. My setup is simple:   1 machine A behind a router B 1 machine C outside, on the Internet   On machine A, I ping machine C, and I want to track what's happening with tcpdump:   tcpdump on machine A shows an ICMP packet from IP (A) to IP (C) Then tcpdump on machine C shows an ICMP packet from IP (B) to IP (C) Then tcpdump on machine C sends an echo reply from IP (C) to IP (B) Then tcpdump on machine A shows an echo reply from IP (C) to IP (A)   So, at some point in router B (I cannot run tcpdump on the router), the IPs are converted from IP (B) and IP (A). I assume that the "real destination IP" = IP (A) should be stored somewhere deep within the ICMP packet, so that the router can redirect it correctly. But I can't find any option of tcpdump to show this "real destination IP" when it's run on machine C? What is this option, or how can I see it?

If several computers with local addresses (192.168.0.#) are connected to a router and each computer opens a web browser and requests a page over HTTP, when these TCP:80 packets are sent out, the router switches the local address with the static IP of the router (i.e. Provider given IP) so the server can reply to the appropriate address.   But how does the router know to which computer to forward the HTTP reply, since the TCP header does not contain the local IP address (does it?), and all computers are using port 80?  Does this have anything to do with the MAC addresses?   How exactly does this work?


I wrote the following program:  numb= ["First", "Second", "Third"] players=[] n = '' score=[]  for i in numb:     print("Type the score of the name of the", i, "player:")     answer = n = str(input(' '))     players.append(d)  for a in players:     for b in numb:         a = int(input("Type the", b, "score of", a))         if a!=0:             score.append(a)         else:   I want to avoid advancing the inner loop for b in numb: as long as a is 0.  For example: if the first score is 0, the program will print again "Type the first score...".


It was a show where a guys played a card game and eventually entered a world where said card game allowed you to turn into your cards and battle other players. I can't remember much besides small details like an area where the main characters would relax and get food watching other matches

I remember very little but enough... I know that there were 3 worlds, a real one, a mid-world kind of with a teleporter, and the world with all the creatures. The first episode was in the desert and there was a good monster that saved the main guys from a bad one. Before he saved them he said every end is a beginning and every beginning is an end.   Please help me; I've tried everything. I saw it on , I think it was not Japanese. I live in Croatia, so I saw it there. It was aimed at kids, but not younger kids. The main characters were human, around 15 years old. The teleporter was in the middle of a big structure. It was a 6 piece tp, so every circle was one, and it was shaped like a star. There were robots working there; they carried food and other things.  I remember that all the creatures thought that the humans are evil, all but the one, the "lord" of all of them. And yes, the main character got to the world by some sort of a device that he found and it belonged to another kid who lost it and they were able to transform in the creatures from the world by it. When they are in the "other world", their body stays in the real world and acts normally but their soul gets transported to the mid-world


When I first setup the SVN structure for my different projects, I decided to place each different project in a separate repository.  This has worked well for a while, but I'm staring to think that I would like to merge all of those repositories into one overall "company-wide" repository so when I have employees check out the source code, they can just checkout from the top and have all the code from all the different projects.  I found the svn-merge-repos command online, but not a lot of user feedback or helpful tips for using it.  Is this the best way to join repositories so I don't loose my history data, or is there a better way?  Are there any pitfalls that I should watch out for?  Thanks.

After considering the answers to my previous question (), I've decided to take the 4 or so repositories I have and consolidate them into one. This of course leads to the question, what's the best way to do this?  Is there a way to combine two or more repositories maintaining the version history for both?  Edit: I should also point out that I'm using Assembla.com, which does not provide access to the svnadmin command, AFAIK  Another edit: Does this even matter? If svnadmin works on URLs, then it's no problem then.


I have a string,  String string = "sdeLING9497896,\"kifssd9497777 999_13\",Kfsheis9497896e,ersdG9497896,aseLING9497896   erunk15426 \nEsea4521  \"\nSdfes451 45264\" \"kiseliog949775 959_13\"";   I may have spaces, comma, tab or new line character in this string. My requirement is to split this string using space,comma,tab and new line but the spaces inside the double quoted strings should be excluded.   My sample code:  public class RegExTest {      public static void main(String[] args) {         Set<String> idSet = new HashSet<String>();         String string = "sdeLING9497896,\"kipliog9497777 999_13\",KIPLING9497896e,ersdG9497896,aseLING9497896   erunk15426 \nEsea4521 \"\nSdfes451 45264\"";         String ids[] = string.split(**"NEED A REGEX HERE"**);         for (String id : ids) {             if (id.trim().length() > 0) {                 idSet.add(id);             }         }         System.out.println(idSet);     } }   My expectation is: sdeLING9497896, kifssd9497777 999_13, KIPLING9497896e, ersdG9497896, aseLING9497896, erunk15426, Esea4521, Sdfes451 45264, kiseliog949775 959_13  Please guide me to solve this!

I'm new to regular expressions and would appreciate your help.  I'm trying to put together an expression that will split the example string using all spaces that are not surrounded by single or double quotes. My last attempt looks like this: (?!") and isn't quite working. It's splitting on the space before the quote.  Example input:   This is a string that "will be" highlighted when your 'regular expression' matches something.   Desired output:  This is a string that will be highlighted when your regular expression matches something.   Note that "will be" and 'regular expression' retain the space between the words.


What does it mean for a map $\phi$ to be $\mathbb R$-linear or $\mathbb{C}$-linear? I have tried to look for this definition on Google but I cannot find it.

Suppose we have a $f\colon \mathbb{C} \to \mathbb{C} $. I am confused when people say $f$ is $\mathbb{R}$-linear map or $\mathbb{C}$-linear map. What is the difference between these two ?


From  article and  post it emerges the strong connection between Mahalanobis distance and PCA. In particular in the first article I reference it says:  " the squared Mahalanobis distance is equal to the sum of squares of the scores of all non‐zero standardized principal components"  I would like to have a mathematical proof or at least some reference where I can read the proof.  Many thanks

I'm studying pattern recognition and statistics and almost every book I open on the subject I bump into the concept of Mahalanobis distance. The books give sort of intuitive explanations, but still not good enough ones for me to actually really understand what is going on. If someone would ask me "What is the Mahalanobis distance?" I could only answer: "It's this nice thing, which measures distance of some kind" :)   The definitions usually also contain eigenvectors and eigenvalues, which I have a little trouble connecting to the Mahalanobis distance. I understand the definition of eigenvectors and eigenvalues, but how are they related to the Mahalanobis distance? Does it have something to do with changing the base in Linear Algebra etc.?  I have also read these former questions on the subject:       I have also read .  The answers are good and pictures nice, but still I don't really get it...I have an idea but it's still in the dark. Can someone give a "How would you explain it to your grandma"-explanation so that I could finally wrap this up and never again wonder what the heck is a Mahalanobis distance? :) Where does it come from, what, why?   UPDATE:   Here is something which helps understanding the Mahalanobis formula:


I am playing Game Dev Story on my Galaxy Ace. I am on year 25, I have $200.000K, I have Mr X and King, two of them are 5 level hackers and I have a Hardware Engineer, but I am still on my 2nd office, as the 3rd office offer never appeared. I want to buy someone from the Holywood Agent, I want to developea few best consoles, and then I will start a new game. But I seriously want my own console. How can I buy the 3rd office?

In Game Dev Story the number of people is limited by the size of your office, so in the beginning you can only employ 4 people. At some point I was asked if I wanted to move into a bigger office and I'm now wondering what triggers it.  So, what do I have to do to get a bigger office?


I want to use something like Mysql command to show me the structure of postgres tables in a database, Is there a way for it? I main goal is to create an exact copy of the table in another database with postgres sql.  I tries /d+ command, but got the following error:  ERROR:  syntax error at or near "\" LINE 1: \d   My OS is windows XP SP3. I've read the following post but gain no success:   EDIT: \d+ command output on windows  :    ERROR:  syntax error at or near "\" LINE 1: \d+

How do you perform the equivalent of Oracle's DESCRIBE TABLE in PostgreSQL (using the psql command)?


Not going too High Potential.  Say a 200V supply.   If somebody accidentally touches the bare terminals of supply, for which case ( AC or DC ), the effect on the person will be more dangerous.   And in which particular case more precaution should be taken ?

Is alternating current more dangerous than direct current?  And give me explanation for that... Assume that 230 V, 50 Hz AC voltage and 230 V DC voltage. Which is more hazardous to human life?  Which has more probability of risk?


I am currently monitoring a change event on a table cell with ID drawing-n-1. all works, except when I delete this cell and then recreate it in Javascript. the event is no longer picked up. any help on this please  Code to monitor the cell value:  var drawing_input = 'drawing-n-1'; $('#'+drawing_input).change(function(e) {     var data = $('#'+drawing_input).val();     console.log(data); });   html code to create the table:  Drawings

     Drawing Number	     Description	     Sheet Number	     Issue

     <textarea name="drawing-n-1" id="drawing-n-1"  /></textarea>	     <input name="drawing-d-1" type="text" />	     <input name="drawing-s-1" type="text" />	     <input name="drawing-i-1" type="text" />

   Function used to delete row and recreate the row  function clear_drawing_Table()  {     var table = $('table#myTable tbody');     for(var i = 1;i<document.getElementById('myTable').rows.length;){         document.getElementById("myTable").deleteRow(i);     }     len = document.getElementById('myTable').rows.length -1;         table.append(                            '
<textarea name="drawing-n-'+ (len+1)+'" type="text" />	<input name="drawing-d-'+ (len+1)+'" type="text"/></textarea>	<input name="drawing-s-'+ (len+1)+'" type="text" />	<input name="drawing-i-'+ (len+1)+'" type="text" />
'       );     $("#myTable").trigger('create'); }

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


I have looked for a ranged weapon with an 18-20 critical threat range. So far I have only been able to find the  but obviously it is not a good option for a main weapon as it shatters after each hit.  Is there a ranged weapon, preferably a bow or crossbow, in Pathfinder that has a crit range of 18-20?  3rd party is accepted.  Related to  This question has a slightly broader range of including all ranged weapons and also not limited to official Paizo weapons.

I am looking for an 18-20 bow or crossbow for my Magus 8 / Arcane Archer 10 Although I expect it to be x2, if it is x3, that would be phenomenal.  Alternatively a 20 x4 bow.  I have the feat to burn for it.


"They say the sky is blue"......hypothetically speaking or theoretically speaking (which is the right phrase to use if you thinking of evoking a debate on the matter).  If am thinking its any colour but blue.

What is the difference between the phrases "hypothetically speaking" and "theoretically speaking"? If one wants to make a point using an example that would likely never happen, which phrase would be more appropriate?


Based on a question I asked prior to this, how would I qualify this string...  "MyCustomObject.prototype.foo.bar"   to this:  window['MyCustomObject']['prototype']['foo']['bar']   in object form? (it must not qualify to...  "window['MyCustomObject']['prototype']['foo']['bar']"   ...as a string!).  As a reference, consider the following...(the code is wrong...it needs fixing (without the eval keyword))  var fn = "MyCustomObject.prototype.foo.bar"; var ptr = fn.split('.'); var ptrPath = 'window' for(var index = 0; index < ptr.length; index++) {     ptrPath += '[\'' + ptr[index] + '\']'; } ptrPath = function() {     alert("Hello"); }   should resolve to this;  var inst = new MyObject(); inst.foo.bar();  //alerts...."Hello"

I have the name of a function in JavaScript as a string. How do I convert that into a function pointer so I can call it later?  Depending on the circumstances, I may need to pass various arguments into the method too.  Some of the functions may take the form of namespace.namespace.function(args[...]).


Several times in the movie, Cobb says that no one should touch your totem, which would otherwise lose its ability to tell you if you're in a dream or not.    I understand, there is no "magical" ability in the totems. Just a way they are done/built, how their owner feels them so that you're the only one knowing how they should behave in reality and in dreams.  The other people wanting to trap you in a dream would then not be able to recreate all these details, which will then help you know if you're in a dream or not.    Concerning Cobb's totem, the top: it was Mal's totem, before being Cobb's totem. Then Saito also plays with it near the end of the movie. Several people touched it then and can know how it feels, even if they don't know the forever-spinning thing.        But Cobb also tells to Ariadne during the movie the special ability of the forever-spinning of the top in dreams. Ariadne could, mixing this with the information of people having touched the totem, recreate this in a dream and then fool Cobb.  As it seems she wants to help him, she knows all that, as well as his after-work dream sessions, she could have built a dream to trap him and having the top falling in the dream, having Cobb thinking he's in reality. In particular, the end could be a dream with Ariadne influencing the top's spinning.   At the end, is the top's spinning a reliable fact to know if he's dreaming or not?

Since Inception is on, I have been thinking about this question a lot.       Cobb's totem used to be his wife's. Doesn't that invalidate its purpose. The other question...is his projection of her really her trying to wake him up?


I have created a game that when started, a start page/ window is displayed with the option to exit or start the game. A second window should open on the start button click but it gives the following error:  Exception in thread "JavaFX Application Thread" java.lang.NullPointerException: Root cannot be null   I have read up on this error but no suggestions seem to work. This is my main class with the start method:  package game;  import javafx.application.Application; import javafx.fxml.FXMLLoader; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.stage.Stage;  import java.io.File; import java.net.URL;  public class AdventureGame extends Application {     @Override     public void start(Stage primaryStage) throws Exception{         primaryStage.setTitle("EBRUTATEN - The Curse of Methuselah");         URL url = new File("F:\\[0] Programming 3.1\\[0] CAPSTONE ASSIGNMENT\\[0] Current Working File\\MyJavaFXGame2\\src\\fxml\\sample.fxml").toURI().toURL();         Parent root = FXMLLoader.load(url);         Scene scene = new Scene(root);         primaryStage.setScene(scene);         primaryStage.show();     }      public static void main(String...args) {         launch(args);     } }   And this is the start button method in its controller class where the button action is handled      public void startButClicked() {         startBut.setOnAction(event -> {             Parent gameOutput = null;             try {                 URL url = new File("F:\\[0] Programming 3.1\\[0] CAPSTONE ASSIGNMENT\\[0] Current Working File\\MyJavaFXGame2\\src\\fxml\\game.fxml").toURI().toURL();                 gameOutput = FXMLLoader.load(url);             } catch (IOException e) {                 e.printStackTrace();             }             Scene gameView = new Scene(gameOutput);             Stage secStage = (Stage) ((Node) event.getSource()).getScene().getWindow();             secStage.setScene(gameView);             secStage.show();             mediaPlayerStarterMusic.stop();         });     }   Any advice would be appreciated.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


My gas valve is inbetween two plasterboard walls How should I access this valve to try to shut it off or maybe have a new valve installed? I've already cut the hole bigger to get my hand in there but don't want to create an even bigger hole but not sure what to do. One side has a water heater and I can't access the valve and this side is where the stove is and I'd like to get a new stove but I cant turn off this valve and maybe I need a new valve but I cant see the valve the way its positioned in the wall. Any ideas?

I want to get a new stove and when I pulled out the old stove I found the gas line within a hole in the wall and the gas line had a metal bar on its side. I am thinking this bar is a gas valve but I am not sure I haven't seen a pic of a gas valve that looks like this on the internet. Also when I tried to move it it seems to jiggle a little but I couldn't get it to move. Has anyone seen this before and can let me know if it is the gas valve and how I can get it unstuck to move it to turn off the gas?


Hy!  How can i update my 16.04.1 to 16.04.3 ?  I tried:  sudo apt update sudo apt upgrade sudo apt dist-upgrade   But   uname -a   said :  Linux lawyer 4.10.0-35-generic #39~16.04.1-Ubuntu SMP Wed Sep 13 09:02:42 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

I wanted to upgrade to 14.04.2 point release from 14.04.  What I did was:  sudo apt-get update && sudo apt-get upgrade &&  sudo apt-get dist-upgrade -y   Then I wanted to upgrade to 3.16 kernel, since it wasn't done with the the above command, so what I did was:  sudo apt-get install linux-generic-lts-utopic xserver-xorg-lts-utopic libegl1-mesa-drivers-lts-utopic xserver-xorg-video-all-lts-utopic xserver-xorg-input-all-lts-utopic sudo apt-get install linux-signed-generic-lts-utopic   Now when I do:   uname -a I get   Linux Y500 3.16.0-33-generic #44~14.04.1-Ubuntu SMP Fri Mar 13 10:33:29 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux  cat /etc/os-release | grep VERSION= I get  VERSION="14.04.2 LTS, Trusty Tahr"   And when I do lsb_release -a I get  Distributor ID: Ubuntu Description:    Ubuntu 14.04.2 LTS Release:    14.04 Codename:   trusty   I know that uname -a and lsb_release -a both refer to different info, but why does  cat /etc/os-release | grep VERSION= show different version?


I plan traveling to Canada in order to visit my brother (and his family) and to travel around for 3 weeks in Canada. I know that I can fill all the visa forms online, but a friend told me that if I will make a mistake, or somehow miss something my visa application will be rejected and I will not be able to apply again.  so I have 2 options either to use the service of a lawyer or the services on an agency like canadianvisaexpert.  I now that in the end of the day a lawyer as well as canadianvisaexpert just fill up forms for me, but as this is their job, they probably will not do any mistakes. saying that are agencies like canadianvisaexpert are legit service provider that can actually do what they say or should I use a lawyer?

I came across these guys: Canadian Visa Expert, who claim to be able to process visas to Canada, for work or study, for a fee of $467 (four hundred and sixty-seven dollars), and to carry out some assessment tests too. They claim to be legit (which is what most scammers would say), and to be recognised by he Canadian government.  I'm not sure if these guys are scammers, or if they are genuine. Please, has anyone used their service successfully before? Or do you know of anyone who has fallen victim to their scam? I just want to be sure.  A message in their terms of use saying they're not affiliated to the Canadian government:     By visiting or using any of CanadianVisaExpert's Websites or Offered Products you acknowledge and are aware that CanadianVisaExpert is a private corporation and is not and does not pretend to be, an official organ of the Canadian Government or otherwise connected to the Canadian Government in any way whatsoever. CanadianVisaExpert is not part of the Canadian Government or immigration authorities, or a law firm. In this respect CanadianVisaExpert neither intends nor claim to provide Legal advice or solutions to an individual's specific problems."


I've noticed that some Americans pronounce dr as jr , such as:  draft → jraft Andrew → Anjrew  Is this standard pronunciation?

Observed some words get pronounced with a /sh/ rather than /s/ in certain situations.   Stripes as "Shtripes" (from some "The Wire" episode) Screw it as "shcrew it" (from a rap song)   In both situations, it seems to be a matter of emphasis, but is there some generic etymological root to this, e.g. a yiddish language background?


After two days I have earned some reputation on Stack Overflow but on  my reputation is still 71 and not getting updated however my Stack Overflow reputation is 96 right now.

Possible Duplicate:          I have created my profile in Careers 2.0. But my reputation is not updated. It shows 392 reputation while it is the reputation when I created the profile. Is there any way to update it? This is my  and here is my


I'm having difficulties resetting admin password on my Ubuntu 12.04 if the username has a space eg. Buggs Bunny? At the prompt it will only display Buggs and wont allow the password command to work

I can't figure out how to write the path of a folder that includes spaces in its name (in Terminal).  I tried:  cd /path/path/path/"A Folder"/file  cd /path/path/path/'A Folder/file  cd /path/path/path/A_Folder/file   but they all return the error through the terminal:  [command]: cannot access '/path/path/path/A Folder/file' No such a file or directory    I can still access it through steps like so:  cd /home cd user cd Desktop cd "Bash Programming" bash Example


I want to test for the entry into the terminal of a single word, i.e. 'Cat' (without anything at the end).  This allows "Cat     ":  re.match(r'[A-Z]{1}[a-z]{1,15}', x)   This doesn't allow even 'Cat' to be entered!:  re.match(r'[A-Z]{1}[a-z]{1,15}[^\s]', x)   What am I doing wrong? To clarify, it asks for an input and the person has to type Cat and hit enter, no spaces at the end. Thanks! :)

I don't really understand regular expressions.  Can you explain them to me in an easy-to-follow manner?  If there are any online tools or books, could you also link to them?


Is there a keyboard-shortcut to switch between different sheet in MS-excel?

Does Excel 2007 have a keyboard shortcut that switchs between worksheets?


There are some strange directories appearing in /home (so far, maybe in other locations too).  These directories do not show up in ls but do with bash's tab autocomplete, when doing things like cd.  The exact name of this mystery directory is .directory.  ls and cd fail on these directories.  P.S. There was more than one in /media, but they seem to have disappeared now.  UPDATE: Output of ls -la /home:  total 12 drwxr-xr-x  3 root      root      4096 Jan  3 11:28 . drwxr-xr-x 23 root      root      4096 Jan  3 11:32 .. drwxr-xr-x 25 bharadwaj bharadwaj 4096 Jan  8 22:58 bharadwaj lrwxrwxrwx  1 root      root        44 Jan  3 11:13 .directory -> /etc/kubuntu-default-settings/directory-home

Initially I thought it was a coincidence, but now I see there's even  for it: all hidden file names start with a dot. Is this a convention? Why was it chosen? Can it be changed? Or in other words (as a related question @evilsoup suggested that implies the answer to a bunch of others): can I hide files without renaming them (using . as the first character of their name)?


When I do anything with apt or dpkg I get this error:   dpkg: warning: file with the list of files from package 'firefox-locale-en' is missing;   Does anyone know how to fix this? I already did:  sudo apt-get update sudo apt-get upgrade sudo apt-get autoremove sudo apt-get -f install sudo apt-get -m install sudo apt-get install -f sudo apt-get install -m sudo apt-get purge firefox sudo apt-get install firefox sudo dpkg --configure -a   And I still get the same problem!  This could be seen as a duplicate of: , But it is not. That has other packages so completely other solutions than mine.

I want to install Open JDK or Oracle JDK to my machine but I got an error during installation. The error is:  Selecting previously unselected package oracle-java8-installer. dpkg: warning: files list file for package 'unity-scope-gourmet' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-guayadeque' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-gmusicbrowser' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-manpages' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-firefoxbookmarks' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-gdrive' missing; assuming package has no files currently installed dpkg: warning: files list file for package 'unity-scope-home' missing; assuming package has no files currently installed E: Sub-process /usr/bin/dpkg returned an error code (2)   I searched on Google and try to something for install/reinstall this packages. Finally i try to remove Unity. I faced this error for my every tries. I am using Xmonad. How can I fix this issue?


I'm writing a book, and I'm trying to describe that the girl is making faces as she's trying to remember something. I'm not quite sure how to describe that. (Seen from the point of view of another character in the book.) So far, I've got this, but I think my sentence doesn't make sense.  She was trying to remember where she’d seen my aunt. She was making faces while thinking, which made her look so cute.  I thought about "grimaces" but that's not it, since grimace is usually in disgust or disapproval.

If you look at this picture, how would you describe the mood and the eyes of the character?  I would not say she's angry. I would say she is concentrating to cut the object. However there are many kinds of concentration, and thus the eye expression can differ. This one gives me the feeling that she doesn't accept the existence of the object, and thus must kill it.


help me please. my galaxy s5 won't charge it says the battery temperature is too high or too low. i used to change my battery but when the new battery runs out of life and when i try to charge it, the same problem exist. what can I do? any helps or suggestion please. thank you.

I have a Samsung Galaxy player that has been giving me the message "Charging paused. Battery temperature too high or too low". I left it unplugged and powered down all night, and it still gave me the message as soon as I turned it on. The battery should be at room temperature. I've turned it off and on several times. I've tried removing the battery and putting it back. I have no idea what's wrong. It's been working fine for the past 9 months. Can anyone help?


trigger VINfromAccountandContact on Case (before insert) {     Set<id> setConids = new Set<id>();     Map<id,id> mapAccidVsVIN = new Map<id,id>();     for(Case c:trigger.new){         if(c.Contactid <> NULL){             setConids.add(c.Contactid);          }     }     if(!setConids.isEmpty()){         for(Contact_Vehicle_Ownership__c cv :[SELECT id,Account_Name__c,Contact_Name__c,VIN_Lookup__r.id FROM Contact_Vehicle_Ownership__c WHERE Contact_Name__c IN:setConids]){             mapAccidVsVIN.put(cv.Contact_Name__c, cv.VIN_Lookup__r.id);         }     }      for(Case c:trigger.new){         if(mapAccidVsVIN.containsKey(c.Contactid)){             c.VIN__c = mapaccidVsVIN.get(c.Contactid);         }     } }   can i know how can i add this condition When accound id is not equal to null

trigger VINfromAccountandContact on Case (before insert) {     Set<id> setConids = new Set<id>();     Map<id,id> mapAccidVsVIN = new Map<id,id>();     for(Case c:trigger.new){         if(c.Contactid <> NULL){             setConids.add(c.Contactid);          }     }     if(!setConids.isEmpty()){         for(Contact_Vehicle_Ownership__c cv :[SELECT id,Account_Name__c,Contact_Name__c,VIN_Lookup__r.id FROM Contact_Vehicle_Ownership__c WHERE Contact_Name__c IN:setConids]){             mapAccidVsVIN.put(cv.Contact_Name__c, cv.VIN_Lookup__r.id);         }     }      for(Case c:trigger.new){         if(mapAccidVsVIN.containsKey(c.Contactid)){             c.VIN__c = mapaccidVsVIN.get(c.Contactid);         }     } }   I want to add this condition when accountid is not equal to Null can any one help how do i add this condition


I'm fairly new to calculus, so if the question seems ridiculous, my apologies. We have  $f = \{(x,e^x) \mid x \in \mathbb Z\}$ Is $f$ continuous on its domain?  So in other words, it is a simple $f(x) = e^x$, with a domain restricted to  integers. I've heard that when some function is continuous, people refer to it as being "smooth". Based upon this, not very rigorous explanation, I would say that the function defined above is not continuous, because there are a lot of "gaps". But since this is definitely not an appropriate approach, we would need to refer to the formal definition:  If $f$ is continuous on its domain, then  $f$ is defined at $a$ ($a \in Dom(f))$; and $f$ has a limit as $x$ approaches $a$; and $\lim\limits_{x\to a}f(x) = f(a)$.   The first condition is clearly satisfied. But what about second and third?   Are they satisfied? Why/why not?

Why is a function f continuous, if it is defined only on integers?   It seems very trivial but I could not find the words to describe the reason. Can smo(someone) give me a hint?  Note: there is no function. This is a verbal question. No equation exists for the function   Thanks


I've an iPhone 5(GSM) running on ios 7.0.3. I can't restore. iTunes says that the IPSW is not compatible?

Have iPhone 4 with iOS 5.1.1 Trying to update to 6.1.2 (not the latest) via downloaded IPSW but unfortunately getting error:     iphone could not be restored device isn't eligible for the requested   build   After searching for fix all over the internet found some suggestion like putting # in hosts file in line gs.apple.com but not helped.  Have you any idea why I'm getting this error and can't restore iphone?


Do you remember the first time you talked about our future together and I said: “I’ll think about it later”?   I lied. I lied that I can be with you forever and never leave.   Do you remember our movie nights when you said how fun it would be if we’ll stay like this forever? I was afraid. Afraid, that I can’t stay like that forever.   The kindness and love that you carry inside your heart can melt anyone. But why didn’t those three magical words try to come outside of me, ever wondered? The answer is commitment.   Commitment, which forces you to stay there and stick. Commitment has always been a scary thought to me. Maybe I’m afraid of a forever.   Do you think I’m the only one who tries to repel people who get too close to them?   (Story by Rashi Arora (@rashiousness) for )

Is there a pronoun I can use as a gender-neutral pronoun when referring back to a singular noun phrase?  Each student should save his questions until the end. Each student should save her questions until the end.


I am getting my maps from QGIS ready for publication in a journal. The journal requires colour images to be tif format in the CMYK colour space. I understand how to save images as tif, but I cannot see a way to see whether I am saving them in the right colour space. Can anyone help me??

In QGIS 2.14, in print composer I can save my project as a PDF file. There is no controls of the color space in which colors are specified in the output file. It will be very useful to have a choice of the color space: RGB or CMYK.  Is it possible to resolve this issue ?


I have two pokestops accessible from my desk at work, close enough together that when both of them have lures the zones of influence overlap.  Is it beneficial to put down lures on both of these stops at the same time? Will the overlapping area have an even greater chance of spawning pokemon, or will it just be wasting resources on a larger area with the same chances of spawning?

So, in my town there are a few areas where multiple Pokestops are in your usable radius at once. If some friends and I use a lure module on one each will the effect stack or is that a waste of modules?


At the grub menu when I select windows 7, it does not take me there instead, it just returns to the grub menu and ask me to select the OS. I have no problem booting to ubuntu. Would you kindly help me fix this guys?

I installed Windows on my computer, followed by an installation of Ubuntu. However, now I'm unable to boot into my Windows install.  What can I do to fix this?


I’m self-studying physics and mathematics out of interest and I am looking for some non-rigorous (text)books on mathematics. Perhaps one book covering all areas relevant to physics or separate books in the areas of non-linear dynamics, differential equations, differential geometry, group theory, etc.  I am explicitly looking for non-rigorous, intuitive approaches to these fields. I feel overly rigorous books make the material needlessly difficult (to me often impossible) and slow to read.  I am looking for things in the style of student’s guides, such as Dan Fleisch’s “A Student’s guide to vectors and tensors” but then more expanded:   Also, a mathematics book that shows the bigger picture on mathematics would be of interest. Something more or less popularising.

What are the best textbooks to read for the mathematical background you need for modern physics, such as, string theory?  Some subjects off the top of my head that probably need covering:   Differential geometry, Manifolds, etc. Lie groups, Lie algebras and their representation theory. Algebraic topology.


I have an esp32 nodemcu hooked up to a powerbank. My issue is that the power consumption is so low, that the powerbank thinks there's nothing connected to it and some electronics inside then tell it after a few minutes to stop delivering power to that port.  It's running a Bluetooth GATT server, so my next attempt is to make it try to constantly connect to an WiFi AP in parallel, but I'd like to know if there is another way, ie by using a variable resistor, but I'm not sure where to put it.  It should be as compact as possible, so no adapter between the USB plugs.

I usually power my beginner prototype circuits using mb102 power supply board, but it needs an external elimeter to draw power and then regulate it.  I was looking for a portable solution for my 5 volt and 3.3 volt circuit needs and came up with using a portable battery charger for mobile phones.  I tried powering up a simple transistor and LED circuit with it but it wouldn't power-up.   I feel that there is some load sensing circuit in the portable charger which doesn't detect these low power circuits.  I also tried connecting different resistors to the charger, the charger outputs 5 Volts for a few seconds and then again shuts down and doesn't stay ON continuously.  It would be really comfortable to use a portable charger since it could be charged using a phone charger and would be very handy.  What can I do to make the charger output power on low loads?


After cleaning up old unnecessary disk partitions, my UEFI/hardware will not find my single and only remaining Ubuntu installation, a perfectly working newly upgraded Ubuntu 20.04 on a disk partition /dev/sda5 on disk /dev/sda; my system will not boot that installed Ubuntu system but only enter that pre-boot BIOS/UEFI settings user interface where it does not seem to recognize any boot option at all. As I understand it, the more modern way of booting over a UEFI enabled motherboard is to allocate a partition where grub2 will sit alongside proper configuration directing grub2 at my /dev/sda5 installed Ubuntu system. Which is arguably now missing after my cleanup of old partitions. Space for a new partition for grub2 is not an issue: I have a ~200MB empty and contiguous unallocated disk space in my disk's partition table for that disk. I can also shrink my Ubuntu partition to get more space for a new partition if more is needed. I have found various conflicting posts and posts answering to a very specific scenario, or to a Microsoft Windows compatibility scenario, on various stackoverflow websites (askubuntu and others) but would like to have a clean, up-to-date, UEFI oriented procedure ― for making a system boot into an existing Ubuntu system via UEFI by recreating a grub2 partition for UEFI from scratch. In Summary Looking for a clean scratch approach ― one based purely on a live USB Ubuntu disk and on commands/tools available on the later releases of the Ubuntu distribution, which will accomplish a UEFI compliant partition that will direct the UEFI hardware to successfully load the pre-installed Ubuntu OS partition upon boot! What should be the cleanest series of steps, from creating a new partition for grub2 for the UEFI hardware to use, to configuring it to point to my /dev/sda5 fully operational Ubuntu? Disk Information as much as it matters, according to gparted the disk's partition table type is gpt. Further Clarification Edit: I have had no functioning UEFI partition on the same disk at the time of asking. My question assumes that one removes it and builds it from scratch: that you only have an Ubuntu OS partition on the disk and your goal is to "connect it" such that UEFI hardware will become able to boot it.

I installed Windows 7, which ate Ubuntu's boot file. When starting up the computer, it now goes straight to Windows, without giving me the option of booting Ubuntu.   How can I get Ubuntu back?


It has happened with me a lot of times, when the text I wrote was cleared after a flag dialog was dismissed.        Please, don't clear the message, when window dismisses.

Sometimes when in the middle of writing a custom moderator flag, I click outside the flag dialog, for example because I want to get a link to one of the answers. This closes the flag dialog and forces me to write my message all over again, which is rather annoying. Therefore, I propose that clicking outside the flag dialog don't close it when I'm in the middle of typing something in a textbox (a custom moderator flag, a custom close reason, etc.).


I live in the house next to/close to the cinema.    I live in the house that is next to/close to the cinema.         I go to the school in front of/behind my house.    I go to the school that is in front of/behind my house.         I work at a supermarket far from my place.    I work at a supermarket that is far away from my place.         My friend lives in the apartment block opposite mine.    My friend lives in the apartment block that is opposite mine.         Which ones are correct and make sense? Are there any rules or guidelines for this kind of structure?

When I write something like this:     I am a man that is doing these things.   Is it correct to shorten it like this?     I am a man doing these things.   And does it require commas?


I'm addled why there are comments with "you falsely claimed", and they're upvoted. The title of post unmistakably states "a moderator unilaterally deletes Meta questions", and I've never edited it. I screenshot the deleted questions to elucidate.    A moderator at Quantitative Finance deleted  that questions the deletion of the , . The moderator  on one of the now-deleted meta questions:  We have discussed this exact same question before. Specific questions are not a topic for meta. Discuss in the comments on the main site.   How can I "Discuss in the comments on the main site" if the original question is now deleted?  If a moderator deletes Meta questions on why main site questions were closed, then where else can I possibly question such closures?

One or more of the following things happened to me on a Stack Exchange site:   My post(s) were wrongly deleted or locked by a moderator A moderator posted a wrong comment on one of my posts I was suspended, but did not do anything wrong I asked a meta question, but the question was closed and/or deleted A moderator discredited me in public ...   I think a moderator has abused their power, but I feel powerless against them.  What recourse do I have now? What can I do when I feel that a moderator has abused their power, and has been repeatedly unfair in their dealings with me?


Let π:C′→C an unramified double cover of a complex Riemann surface C of genus g. With the symbol Nmπ we mean the norm application that takes a meromorphic function on C′ named h and produce a meromorphic function on C named Nmπ(h) defined as Nmπ(h)(p)=∏q∈π−1(p)h(q)ν(q)  where ν(q) is the multiplicity of q in the fiber of p respect to π. Write (f)=(Nmπ(h)) the principal divisor associated to the function Nmπ(h).  I would like to prove that: 1) if τ:C′→C′ is the sheet interchange involution for the double cover π. Show that there exist a function s meromorphic on C′ such that s(q)=−s(τ(q)) 2)Let τ as in the point 1) and let f a meromorphic function on C′ such that f=−f∘τ. Show that (Nmπ(f)) is divisible by 2 i.e. we can write (Nmπ(f))=2D.

Let $\pi:C^{'} \rightarrow C$ an unramified double cover of a complex Riemann surface $C$ of genus $g$. With the symbol $Nm_{\pi}$ we mean the norm application that takes a meromorphic function on $C^{'}$ named $h$ and produce a meromorphic function on $C$ named $Nm_{\pi}( h)$ defined as $$Nm_{\pi}(h)(p)=\prod_{q \in \pi^{-1}(p)} h(q)^{\nu(q)}$$ where $\nu(q)$ is the multiplicity of $q$ in the fiber of $p$ respect to $\pi$. Write $(f)=(Nm_{\pi}(h))$ the principal divisor associated to the function $Nm_{\pi}(h)$. I would like to prove that: 1) if $\tau: C^{'} \rightarrow C^{'}$ is the sheet interchange involution for the double cover $\pi$. Show that there exist a function $s$ meromorphic on $C^{'}$ such that $$ s(q)=-s(\tau(q))$$ 2)Let $\tau$ as in the point 1) and let $f$ a meromorphic function on $C^{'}$ such that $f=-f \circ \tau$. Show that $(Nm_{\pi}(f))$ is divisible by 2 i.e. we can write $(Nm_{\pi}(f))=2D$.


I see the link about the use of this is jQuery. Yes, the problem was exactly this, but this situation is a completely different one, so please remove useless links to other questions and mark as duplicated because this can lead to confusion to a poor SO user looking for a more simple situation.  Also: my code is fully pasted here, not just a snippet, and my code is not using some complicated binding at all, is more basilar. So it's a complete new question for me  This is my full working code  var game = {     status : {         NOT_INITIALIZED : "gamepad:not_initialized",         INITIALIZED     : "gamepad:initialized",     },     _selector : null,     _status   : null,     init : function( gamepad_selector ) {         this._selector = gamepad_selector;         $(this._selector).on(this.status.NOT_INITIALIZED, this.onNotInitialized);         this.setState(this.status.NOT_INITIALIZED); // just to force the first console log         $(this._selector).on(this.status.INITIALIZED, this.onInitialized);         this.setState(this.status.INITIALIZED);     },     setState : function ( new_status ) {         this._status = new_status;         $(this._selector).trigger(new_status);     },     onNotInitialized: function () {         console.log("onNotInitialized()");     },     onInitialized: function () {         console.log("onInitialized()");     }, }   The entry point is a call to game.init().  Note that on the init function, I can call setState using one of the predefined status. This works.  this.setState(this.status.NOT_INITIALIZED);   I tried to avoid using of this.setState, so I deleted this function and tried to set this._state directly into the event listeners.   This the significative parts of not working code:  init : function( gamepad_selector ) {     ....     console.log ("a");     $(this._selector).on(this.status.NOT_INITIALIZED, this.onNotInitialized);     console.log ("b");     $(this._selector).trigger(this.status.NOT_INITIALIZED)     console.log ("c");     .... },  onNotInitialized: function () {     // I can't do this: throws an error     this._status = this.status.NOT_INITIALIZED;     console.log("onNotInitialized()"); },       The problem: at runtime I got this error:  Cannot read property 'NOT_INITIALIZED' of undefined   related to   this._status = this.status.NOT_INITIALIZED;   The error is at runtime, not at 'compile' time (please forgive me the term), because I can see on the console log both a and b. But not c.  Why can I explicitly use this.status.NOT_INITIALIZED in init but not in onNotInitialized ?

I have created a 'control' using jQuery and used jQuery.extend to assist in making it as OO as possible.  During the initialisation of my control I wire up various click events like so  jQuery('#available input',              this.controlDiv).bind('click', this, this.availableCategoryClick);   Notice that I am pasing 'this' as the data argument in the bind method. I do this so that I can get at data attached to the control instance rather from the element that fires the click event.   This works perfectly, however i suspect there is a better way  Having used Prototype in the past, I remember a bind syntax that allowed you to control what the value of 'this' was in the event.  What is the jQuery way?


I am new here. I am a Brazilian learning english and I'd like to understand these articles' titles:  Examples:  Bethesda to release Dishonored 2  Facebook to buy Whatsapp  Donald Trump to build solar panelled wall on the border  I mean, I can understand them, but when to use this type of sentence construction? For me it seems like something is missing.

From time to time I come across a sentence with to + verb, but with no other verb in it. I see it often in news titles. For example:     Squall, Tina and Lightning to appear in Final Fantasy Explorers   But what does it mean? What is the difference between this form, and that:     Squall, Tina and Lightning are appearing in Final Fantasy Explorers   The first time I saw that, I thought it was a mistake.