Date is not being read by JFormattedTextField? Gives `java.lang.NullPointerException`
What is a NullPointerException, and how do I fix it?
What's the difference between the simple past tense and the present perfect? The simple past tense indicates that an activity or situation began   and ended at a particular time in the past.      The present perfect expresses the idea that something happened (or   never happened) before now, at an unspecified time in the past.The   exact time it happened is not important. It also expresses the   repetition of an activity before now. The exact time of each   repetition is not important.   Even though I understand the explanation above, I can't figure out: If the present perfect states the idea that something happened in the past, why not use the simple past?  For example, would you please explain the following sentence to tell the difference between these two tenses?         The plane crashed there.    The plane has crashed there.      What is the biggest difference between them? I was trying to fix my audio problems using suggestions from . One of the comments suggested I execute this and only this:     killall pulseaudio   So I did, and I restarted my computer just in case, but all it did was remove my soundcard and I still couldn't hear anything. Now I don't know how to get my soundcard back.  Please note that I am extremely inexperienced when it comes to Ubuntu. Lunch Meeting Probability for two person to meet in given 1 hour slot and none would wait more then 15 minute. Two friends who have unpredictable lunch hours agree to meet for lunch at their favorite restaurant whenever possible. Neither wishes to eat alone and each dislikes waiting for the other, so they agree that each will arrive at a random time between noon and 1 pm, and each will wait for the other for 15 minutes or until 1:00. What is the probability that the friends will meet for lunch on a given day? Co-signed a loan and I need to have my name removed Clip vector on Geoprocesing QGIS 2.18.13, global name 'features' is not defined I want to clip a vector polygon with a boundary vector polygon but the process is failing. I am getting the error, "global name 'features' is not defined See log for more details". I don't know what is causing this error. I am making a Minecraft Mini Game adventure map, and one of the levels has a /setblock command, I am using the command in a way to spawn an item in a chest (Wooden Button) I need the wooden button to have CanPlaceOn tag so it can be placed on a log. I have tried this command: setblock 294 5 -1251 minecraft:chest 0 replace {Items:[{Count:1,Slot:0,id:minecraft:wooden_button,CanPlaceOn:[log]}]}` Best method for short time-series I have a question related to modeling short time-series. It is not a question , but how. What method would you recommend for modeling (very) short time-series (say of length $T \leq 20$)? By "best" I mean here the most robust one, that is the least prone to errors due the fact of limited numbers of observations. With short series single observations could influence the forecast, so the method should provide a cautious estimate of errors and possible variability connected to the forecast. I am generally interested in univariate time-series but it would be also interesting to know about other methods. Strange book where teen protagonist is sent to a warzone, uses illusory magic to grow male genitalia We have been using Notes and Attachment to store files related to the record. I also read about Files in salesforce.   How are Files different from Attachment? Are there any limitations or benefits of using Files instead of Attachments?  Are Files available for all editions of Salesforce?  Is it possible to link Files to particular records so they are visible as related list? I tried looking into the content version  but cant seem to find anything to relate to a record Multiplication operator has no no eigenvalues Statement: Let $M_x$ denote the multiplicative operator acting on $L^2([0,1], \, dx)$ by $M_x(f) = xf$. Show that $M_x$ has no eigenvalues  Attempt: Let $M_x(f) = xf$ then we should have $M_x(f) = \lambda f$  then we get $M_x(f) = \lambda f \Rightarrow xf = \lambda f \Rightarrow xf-\lambda f \Rightarrow (x-\lambda)f = 0$  Now $f \neq 0$ so that implies that $(x-\lambda) = 0$ but this is achieved when $x = \lambda$, so I don't see how it doesn't have eigenvalue, when we achieve the desired result. How to customize Windows 10 "6 Folders" in My Computer I would like to customize the folders in the Default Folders group of My computer. It is not necessary to have the same folders appear on the left sidebar and in the middle view. How can I do that ? I have been reading Terry Tao's notes on Real Analysis and there's a part he just says, but does not really explain, so I am wondering if someone here would. The notes are  and my particular question is from Section 4, Corollary 3. It goes as follows,  Let $f_n \rightarrow f$ in $L^1$ then there exists a sub sequence $(f_{n_j}) \subset (f_n)$ such that $f_{n_j} \rightarrow f$ pointwise a.e. Moreover $(f_{n_j})$ converges almost uniformly to $f$.  The proof he gives is simply that since $\|f_n-f\|_1 \rightarrow 0$ as $n \rightarrow \infty$ we can pick a sub sequence such that $\|f_{n_j}-f\|_1&lt;2^{-j}$ which is enough to show pointwise a.e and almost uniform convergence. But what allows you to pick such a sub sequence is it maybe some Cauchy property or is it some weird construction? Then how do you go from that to pointwise a.e and even almost uniform convergence. I am assuming that for almost uniform, you do something similar to Egorov's theorem without the assumption the domain of $f$ has finite measure. Also I am aware that if you get almost uniform, you immediately have pointwise a.e, but I'd like to see how to get to both. Thank you. We often get questions on bicycles.stackexchange about identifying a bicycles manufacturer, model, make, and year.  Often these questions are downvoted or closed -- usually with a comment attached to them that it's not necessary to know the exact model/make/year of a bicycle if you want to fix, repair, or ride your bike. Why should owners not care about the model/make/year of their bicycle? Especially when it comes to less expensive bikes (aka BSOs) and BMX bicycles? This is intended as a canonical question that we can point closed questions to. Also see      (generally not helpful for identifying a brand/model) Is the 64-Bit version of Ubuntu only compatible with AMD CPUs? My pixel perfect picture gets blurry when compiled in LaTeX I have this picture:  (I have the original in Pixen and could export it to several different formats. I went with PNG though since it's lossless.)  When I open my picture in Preview (OS X) and zoom in, it looks fine. The characters have extremely sharp boarders between them and the background. However, when I put it into my LaTeX document, compile it to a PDF (using TeXShop) and then zoom in, it suddenly have gotten blurry (see screenshot: ).  Minimal working example:  \documentclass[12pt]{article} \usepackage{graphicx} \begin{document} \includegraphics[scale=1]{fig1.png} \end{document}   In the end, I would like to be able to scale the picture freely without there being any blurring at all. What is the best way to iterate over a dictionary? How do I get a straight quote instead of curly quotes? I’m not inside verb or listing or any other special environments, and I’m not using XeLaTeX or anything—just normal LaTeX. I don’t want to change all quotes, just get the occasional straight quote. For example, I’d like a way to get something like this in the TeX:  ... some examples of these glyphs are curly quotes (``''), straight quotes ('"), and angled quotes ($'$$"$) ...   to look like this in the output:  ... some examples of these glyphs are curly quotes (“”), straight quotes ('"), and angled quotes (′″) ...   As I’m using an academic-publisher-provided template that does its own required font setup, I’m extremely wary of changing fonts or font encodings. I think the template uses the times package, and the formatting instructions say all fonts must be Type 1. TikZ 3.0.0 (release) produces strange shadings if used with XeLaTeX and standalone I would like to use shadings in my TikZ graphics together with the standalone package and XeLaTeX, but for some reason it is broken if I try with the new 3.0.0 release (). Any other combination I tried works for me (use for example article class/pdflatex/lualatex/TikZ 2.10). (I'm using a fully updated TeX Live 2013.) MWE \documentclass{standalone} %\documentclass{article} % would work  \usepackage{tikz} \usetikzlibrary{shadings}  \begin{document} \tikz \draw[top color=red] (0,0) rectangle (2,1); \end{document}  Output  Expected Output  Question How can I avoid the problem and which package/class is causing it? Cosmological constant doubts I have the age-old problem of a div wrapping a two-column layout. My sidebar is floated, so my container div fails to wrap the content and sidebar.  &lt;div id="container"&gt;   &lt;div id="content"&gt;&lt;/div&gt;   &lt;div id="sidebar"&gt;&lt;/div&gt; &lt;/div&gt;   There seem to be numerous methods of fixing the clear bug in Firefox:   &lt;br clear="all"/&gt; overflow:auto overflow:hidden   In my situation, the only one that seems to work correctly is the &lt;br clear="all"/&gt; solution, which is a little bit scruffy. overflow:auto gives me nasty scrollbars, and overflow:hidden must surely have side effects. Also, IE7 apparently shouldn't suffer from this problem due to its incorrect behaviour, but in my situation it's suffering the same as Firefox.  Which method currently available to us is the most robust?