Since we can not assign null value to integer type variable. So I declared int? type variable and used ternary operator and tried to pass the variable as parameter. But getting error.  int? SAP = 0;  SAP = SAP_num == null ? null :Convert.ToInt32(SAP_num);  // SAP_num is string   While trying to do this I am getting error, type of conditional expression can not be determined because there is no implicit conversion betwen '&lt;null&gt;' and 'int'  Then I tried   int? SAP = 0; SAP  = Convert.ToInt32(SAP_num); int confimation_cd = GetCode(SAP);   while trying to do this getting error,cannot convert from 'int?' to 'int' GetCode function accepts integer.  My problem is, if the SAP_num IS NULL , pass as null in the function GetCode else pass as integer value. How to achieve this?
EmployeeNumber = string.IsNullOrEmpty(employeeNumberTextBox.Text)     ? null     : Convert.ToInt32(employeeNumberTextBox.Text),  I often find myself wanting to do things like this (EmployeeNumber is a Nullable&lt;int&gt; as it's a property on a LINQ-to-SQL dbml object where the column allows NULL values).  Unfortunately, the compiler feels that  There is no implicit conversion between 'null' and 'int'  even though both types would be valid in an assignment operation to a nullable int on their own. Using the null coalescing operator is not an option as far as I can see because of the inline conversion that needs to happen on the .Text string if it's not null. As far as I know the only way to do this is to use an if statement and/or assign it in two steps.  In this particular case I find that very frustrating because I wanted to use the object initializer syntax and this assignment would be in the initialization block... Does anyone know a more elegant solution?
Looking for a short story about an artist and a forger Back in the late 1970s to early 1980s, I read a short story about an artist and a forger.  Between the two of them, they managed to start a revolution that brought down a corrupt dictatorship.  It was science fiction:   The dictatorship was interplanetary, maybe interstellar.   The artist used some kind of advanced technology to make his art works.   Plot:  The artist is one of the best (if not the best) at what he does.  The dictator wants the artist to make what amounts to a family portrait in whatever medium it is he works in.  Think of it like painting - you create the image manually (not a photograph) but it is much more than just a flat image.    The artist doesn't like the dictator - maybe on general principles, maybe because he knows the dictator personally - and refuses to make the "portrait."  The dictator has the artist arrested, and will only let the artist free again if he makes the portrait.  The artists makes the portrait.  He does the work while in the prison or jail.  That's where the forger comes into things. The forger is also in jail for something or other.  The forger makes copies of art works.  He of course recognizes the artist, and knows what the artist works with.  The forger can somehow see what the artist is working on.  The artist finishes the portrait.  At first the dictator is thrilled.  It looks exactly the way he wanted it.  As time goes by, though, the people looking at the picture see that it represents the vileness and corruption of the dictator.  The more you look at it, the more of the evilness of the dictator you see in it.  That is the genius of the artist, and whatever medium he is using.  Once you notice the hidden levels of the portrait, you can't unsee them and you see more and more of it as you look.  I think the effect carries over into reality as well.  Once you've seen the dictator's corruption in the portrait you also begin to see it in the dictator and his works as well.  This of course seriously pisses off the dictator, who has the artist killed and the portrait destroyed.  While in prison, the forger watched as the artist created his masterpiece, and recognized it for the subversive thing it is.  He also recognized it as the ultimate rebellion from the artist - the artist knows what will be seen, and that he will be killed for it.  All of that inspires the forger to do something more meaningful with his life than make forgeries for the money.  The forger is released from prison.  He saw the completed portrait, and knows how it was made.  He begins making forgeries of the portrait - like, hundreds if not thousands of them.  These are distrubuted throughout the nation/empire.  The people realize what evil is controlling them once they see it in the copies of the portrait, and eventually a revolution rises and brings down the dictatorship.  It was probably older than the 1970s.  I expect earlier than 1960.  Any ideas? Let $x_1,x_2,\ldots,x_n$ be the roots for $1+x+x^2+\ldots+x^n=0$. Find the value of   $$P(1)=\frac{1}{x_1-1}+\frac{1}{x_2-1}+\ldots+\frac{1}{x_n-1}$$   Source: IME entrance exam (Military Institute of Engineering, Brazil), date not provided (possibly from the 1950s)  My attempt: Developing expression $P(1)$, replacing the 1 by $x$, follows $$P(x)=\frac{(x_2-x)\cdots (x_n-x)+\ldots+(x_1-x)\cdots (x_{n-1}-x)}{(x_1-x)(x_2-x)\cdots (x_n-x)}$$    As $x_1,x_2,\ldots,x_n$ are the roots, it must be true that   $$Q(x)=(x-x_1)\cdots(x-x_n)=1+x+x^2+\ldots+x^n$$ and  $$Q(1)=(1-x_1)\cdots(1-x_n)=n+1$$ Therefore the denominator of $P(1)$ is  $$(-1)^{n} (n+1).$$ But I could not find a way to simplify the numerator.  Another fact that is probably useful is that  $$1+x^{n+1}=(1-x)(x^n+x^{n-1}+\ldots+x+1)$$ with roots that are 1 in addition of the given roots $x_1,x_2,\ldots,x_n$ for the original equation, that is  $$x_k=\text{cis}(\frac{2k\pi}{n+1}),\ \ k=1,\ldots,n.$$  This is as far as I could go...    Hints and full answers are welcomed. Correct tracked camera orientation Identify story: Overpopulation problem causes people to live one day a week This story is about a man that is able to live every day of the week, while everybody else has a single day of wakefulness assigned to them. Due to overpopulation, each human spends 6 out of 7 days of the week in stasis, and has jobs assigned to them in daily shifts. 1/7 of the population works on Monday. 1/7 works on Tuesday, &amp; so on. The main character has found away to circumvent the process and illegally live out his days consecutively by skipping the stasis program that is imposed on the general population and by working a different job everyday. Can somebody name this scifi story? Bash Brace Expansion & Variables I have a find command:  find Directory/{Alpha,Bravo,Charlie} arg1 arg2   I want to replace Alpha,Bravo,Charlie with $find_dir  find Directory/{$find_dir} arg1 arg2   however the latter expands to   find Directory/{Alpha,Bravo,Charlie} arg1 arg2   rather then   find Directory/Alpha Directory/Bravo Directory/Charlie arg1 arg2   Why? It's part of a fairly complex bash script that may have more or less directories, not all which are relevant (so globbing Upload/* would not work). So if I setup three now and add another, I'll have to manually add it in later. Plus I need it run from the root of directories to keep finds outputs perspective (./Upload/Dir/file as opposed to ./Dir/file).   But using a variable would permit me to change that as needed and keep it relevant to other parts of the script. The process substitution &lt;(cat) doesn't work. Why?  head &lt;(cat)  cat: -: Input/output error   I can use an extra file descriptor, but I don't understand why the above doesn't work.  # Using file descriptor 3 to reroute the input (head &lt;(cat &lt;&amp;3)) 3&lt;&amp;0 Affiliate Ads Are Coming To The Network Some time ago, we announced that . This has gone well and we're extremely thankful to everyone for their support and feedback. Because it has been successful so far, we're going to be extending the program to the majority of our graduated sites. Well, we've pretty much already done that, but there are quite a few sites that have ads enabled, yet still display nothing. The thing is, we don't really have an abundance of clients offering products that a  would find relevant, but Amazon has stand mixers, a selection of super fine chinois, deliciously sharp cutlery and enough cast iron to fill the Gulf Of Mexico with . Beginning as early as this week (week of 5 February 2018), our ad team is going to be hand selecting affiliate ads to be displayed on select sites. The use of inventory will of course depend on the availability of relevant ads to display which means:  Some sites might see very few, if any ads. Some topics simply don't come remotely close to orbiting anything worth advertising. Furthermore, while graduated, some sites simply don't have enough activity for ads to make sense.  Since these are hand-selected, it could take a while for ads to appear initially.  These would of course yield to inventory from clients if clients had products that were relevant to any given topic.   Nothing changes when it comes to the . If you're used to occasionally seeing a community promotion ad, you'll just notice that you'll also occasionally see an ad for something that is likely to be of interest to someone interested in the topic that your site covers. In fact, to be clear, this is simply a continuation of the announcement we made in November of 2016. We just wanted folks to know that we're going to be continuing the program where there's good potential to show relevant advertisements, even if we don't have clients lined up with a demand for it. Where can I give feedback about a certain ad on [site]? Open a meta post on your per-site meta and let us know. Please remember, the bulk of advertisements are an effort to get something small back from folks that hit the sites through search engines and are extremely unlikely to ever become contributors. Their soufflé stopped falling, and we'll probably never see them again. Maybe we can get a few bucks once they realized that copper ions help egg whites stiffen properly and buy a bowl or a proper bloom whisk. However, you're the experts on these topics and we're very likely going to listen to you. What sites, specifically? Are any sites exempt? If you're a former Stack Exchange 1.0 site and / or subsequently joined the network under a special charter, nothing changes - don't panic :) For the rest, we're just extending what we're currently doing with ads on graduated sites to also include those where there's an opportunity to make sensible use of affiliate ads. If a site has less than 15k (average) daily visits, or fewer than roughly 50k combined total posts - it might not yet be time to invest in selecting ads to be shown there. But, part of this exercise is also seeing what works best. I don't really have feedback, just some suggestions Ads aren't just an opportunity to sell stuff, they're an opportunity to really show people that we understand a given topic. That, of course, makes suggestions from people that do that stuff every day quite valuable. Post on your per-site meta and our community / ad critters will take a look. Questions? Comments? Kvetches? Let us know in an answer or comment below. If anything about the plan changes, we'll update this post to let folks know. For which values of $\alpha$ and $\beta$ does the integral $\int\limits_2^{\infty}\frac{dx}{x^{\alpha}\ln^{\beta}x}$ converge? I'm trying to find out for which values of $\alpha$ and $\beta$ the integral $\int\limits_2^{\infty}\frac{dx}{x^{\alpha}\ln^{\beta}x}$ does converge. I know that when $\alpha=1$ then $\beta$ must be greater than $1$. I tried to use integration by  parts but It didn't work, so I would appreciate some hints. Thanks in advance. Having links relative to root? What is wrong with \ifnum#1=0.09\relax? The following code does not compile with the following error message     Missing = inserted for \ifnum   \documentclass[pstricks,border=4pt]{standalone} \usepackage{multido}  \psset{linewidth=.5\pslinewidth} \psset{xunit=2cm}  \newcommand\FixedScale[1]{%     \multips(0,0)(.1,0){\the\numexpr10*#1+1\relax}{\psline(0,0)(0,-3pt)}     \multips(0,0)(.5,0){\the\numexpr2*#1+1\relax}{\psline(0,0)(0,-6pt)}     \multips(0,0)(1,0){\the\numexpr#1+1\relax}{\psline(0,0)(0,-9pt)}     \multido{\i=0+1}{\the\numexpr#1+1\relax}{\uput[-90](\i,-5pt){$\i$}} }  \newcommand\VernierScale[2][0.09]{%     \rput(#2,0){%     \psset{xunit=#1,linecolor=red}%     \multips(0,0)(1,0){11}{\psline(0,0)(0,3pt)}%     \multips(5,0)(5,0){1}{\psline(0,0)(0,6pt)}%     \multips(0,0)(10,0){2}{\psline(0,0)(0,9pt)}%     \ifnum#1=0.11\relax         \multido{\i=0+5}{3}{\uput[90](\i,8pt){\tiny$\the\numexpr10-\i\relax$}}     \else         \multido{\i=0+5}{3}{\uput[90](\i,8pt){\tiny$\i$}}     \fi     } }  \begin{document} \multido{\n=0.00+0.01}{21}{% \begin{pspicture}(0,-.5)(2,.55) \FixedScale{2} \VernierScale[0.09]{\n} \end{pspicture}} \end{document}   What is wrong with \ifnum#1=0.09\relax? How to load a taxonomy term with case-sensitive? I used this      $this-&gt;termStorage-&gt;loadByProperties(['name' =&gt; 'test']);   I got two terms: Test, test. I want to get only one: test  This is working without case-sensitive:       $this-&gt;termStorage-&gt;getQuery()-&gt;condition('name', 'test', '=')-&gt;execute();       \Drupal::database()-&gt;select('taxonomy_term_field_data', 't')       -&gt;condition('t.name', 'test')       -&gt;fields('t', ['name'])       -&gt;execute()       -&gt;fetchAll();       \Drupal::database()-&gt;query("SELECT name FROM taxonomy_term_field_data WHERE name='test'")-&gt;fetchAll(); Why do the Jedi say "May the Force be with you"? Why is saltatory conduction in myelinated axons faster than continuous conduction in unmyelinated axons? Turning vector grid into individual shapefiles using QGIS? I am using QGIS and I created a vector grid on a crop field in order to cut it into plots. I want to save each grid cell into individual polygon shapefiles automatically.  Here is an example of a vector grid I would like to split into 117 shapefiles:    Eventually, I did it manually with the selection tool and "Save as" but it is really time-consuming when there are more than 100 plots to save.    Is there any way to do it faster and more automatically?  Each plot as an attribute named "Plot" that can discriminate against them (basically being id + 1). It's the attribute used here to label them. I'd like to install a  client for Xubuntu (12.04).  I'm getting non-English Google results, and I didn't find  in the Xubuntu repositories.   Does anyone know of a client that works well for Ubuntu or it's supported derivates (or installation instructions for grive?) Expected value as a function of quantiles? Implicit 'which is', 'which are' A new study has shown that millions of pieces of junk floating in  space could be a big hazard for satellites orbiting Earth.   Is there an implicit 'which are' in front of floating in space? Why is 'which are'  not written? I entered chmod -R 777 /usr/bin and now sudo is not working.  It says sudo must be setuid root.  Some advice online said to run chown root:root /usr/bin/sudo chmod 4755 /usr/bin/sudo.  On entering chown root:root /usr/bin/sudo it shows an opened in readonly mode error. How to get Intel Dual Band Wireless-AC 3168 work on Ubuntu 16.04? I searched many solutions on this site but most of them were referring to Broadcom Wifi drivers while mine has Intel one.   Output of lspci -knn | grep Net -A2  arijit@HP-AU134TX:~$ lspci -knn | grep Net -A2  05:00.0 Network controller [0280]: Intel Corporation Device [8086:24fb] (rev 10) DeviceName: Intel Dual BandWireless-AC 3168 802.11 ac 1x1 WiFi + BT 4.0 Combo Adapter Subsystem: Intel Corporation Device [8086:2110]   Output of rfkill list  arijit@HP-AU134TX:~$ rfkill list  arijit@HP-AU134TX:~$    i.e No Output  Output of uname -a; dmesg | grep iwl  arijit@HP-AU134TX:~$ uname -a; dmesg | grep iwl  Linux HP-AU134TX 4.4.0-31-generic #50-Ubuntu SMP Wed Jul 13 00:07:12 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux How to solve "permission denied" when using sudo with redirection in Bash? When using sudo to allow edits to files, I regularly get 'permission denied'.  For example, my mouse is jittery and sluggish, so I want to disable polling:  sudo echo "options drm_kms_helper poll=N"&gt;/etc/modprobe.d/local.conf   I'm prompted for a password, and then get:  bash: /etc/modprobe.d/local.conf: Permission denied   So I tried to do a temporary change to disable polling by using:  sudo echo N&gt; /sys/module/drm_kms_helper/parameters/poll   Yet again the system responded with:  bash: /sys/module/drm_kms_helper/parameters/poll: Permission denied   Any ideas?