M using #helpshift app got crash or initializetion of help shift. please follow the logs   java.lang.RuntimeException: Unable to start service com.helpshift.support.HSRetryService@1aba47b with Intent { cmp=com.quizup.core/com.helpshift.support.HSRetryService }: java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.sqlite.SQLiteDatabase android.content.Context.openOrCreateDatabase(java.lang.String, int, android.database.sqlite.SQLiteDatabase$CursorFactory, android.database.DatabaseErrorHandler)' on a null object reference     at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:4079)     at android.app.ActivityThread.access$2400(ActivityThread.java:221)     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1897)     at android.os.Handler.dispatchMessage(Handler.java:102)     at android.os.Looper.loop(Looper.java:158)     at android.app.ActivityThread.main(ActivityThread.java:7224)     at java.lang.reflect.Method.invoke(Method.java)     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.sqlite.SQLiteDatabase android.content.Context.openOrCreateDatabase(java.lang.String, int, android.database.sqlite.SQLiteDatabase$CursorFactory, android.database.DatabaseErrorHandler)' on a null object reference     at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:223)     at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:187)     at com.helpshift.support.storage.ProfilesDataSource.read(ProfilesDataSource.java:27)     at com.helpshift.support.storage.ProfilesDataSource.getProfile(ProfilesDataSource.java:61)     at com.helpshift.support.ProfilesManager.getProfile(ProfilesManager.java:25)     at com.helpshift.support.ProfilesManager.getProfileId(ProfilesManager.java:34)     at com.helpshift.support.HSApiData.getProfileId(HSApiData.java:2059)     at com.helpshift.support.HSApiData.sendFailedMessages(HSApiData.java:1626)     at com.helpshift.support.HSRetryService.onStartCommand(HSRetryService.java:17)     at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:4062)
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?
Are submodules of finitely generated free modules always free? I don't believe it's true that all submodules of a finitely generated free module are free just based on results from google. Is there a canonical simple example of a finitely generated free module with a submodule that is not free? The spell was cast without words, simply a flick of the Death Eater's wand, and a 'streak of purple flame' that lanced across her chest. It was later mentioned that the spell was weakened because of the lack of a verbal component, but still 'did enough damage as it was'. She was in the infirmary healing from the damage for some time. What spell was this? Setting nautilus-open-terminal to launch Terminator rather than gnome-terminal I know it's not possible to install a 32-bit driver in the traditional way, but I really cannot find a 64-bit driver for my memory card reader. Is there anyway I can somehow use this device with a 32-bit driver on a 64-bit Windows 7 installation?  I was thinking there might be a way to run a device in compatibility mode? Possibly even have a 32-bit device layer emulator or something?  I'm interested in any method to get this device up and running. SCJP6 regex issue converge and converge absolutely of a series $f(x)$ is a continuos fuction in $[0, 1]$ and differentiable twice on $0$.  $U_n=(-1)^{n}f(\frac{1}{n})$. I need to prove that:   $1.$if $\sum_{n=1}^\infty U_n$ converge then $f(0)=0$.  $2.$if $f(0)=f'(0)=0$ then $\sum_{n=1}^\infty U_n$ converge absolutely.  Now, from the detail that $f(x)$ is differentiable twice on $0$ I think I need to write $f(1/n)$ with Maclaurin series with 2 degree but it doesn't work very nice. can you guide me please? thanks! I have a DEM that I would like to smooth or generalize to remove topographic extremes (chop off peaks and fill-in valleys). Ideally, I would also like to have control over the radius or level of "blurriness". In the end, I will need a set of rasters that range from slightly blurry to really blurry. (Theoretically, the blurriest would be a constant raster of the arithmetic mean of all values).  Are there any tools or methods I can use (based on Esri, GDAL, GRASS)?   Do I need to home bake my own  routine?   Could I use a low-pass filter (e.g. ArcGIS's ), and if so, would I need to run it a bunch of times to get the effect of a large radius? I want a single word embedded in whole logo. How do i do it in adobe illustrator?  I want to design a logo like this. Kindly help me Let $K/F$ be a finite field extension and suppose that $F$ is infinite. Is it possible to have a nonzero polynomial $p \in K[x_1,...,x_n]$ that vanishes in $F^n$? Imagine a standard machine-learning scenario:     You are confronted with a large multivariate dataset and you have a   pretty blurry understanding of it. What you need to do is to make   predictions about some variable based on what you have. As usual, you   clean the data, look at descriptive statistics, run some models,   cross-validate them etc., but after several attempts, going back and   forth and trying multiple models nothing seems to work and your   results are miserable. You can spend hours, days, or weeks on such a   problem...   The question is: when to stop? How do you know that your data actually is hopeless and all the fancy models wouldn't do you any more good than predicting the average outcome for all cases or some other trivial solution?  Of course, this is a forecastability issue, but as far as I know, it is hard to assess forecastability for multivariate data before trying something on it. Or am I wrong?   Disclaimer: this question was inspired by this one  that did not attract much attention. It would be nice to have detailed answer to such question for reference. Let $f:\mathbb{R}\rightarrow \mathbb{R}$ be continuous.Let $t\in\mathbb{R}$. Evaluate:$\lim_{h\rightarrow0}\frac{1}{h}\int_{t-h}^{t+h}f(s)ds$ Having trouble creating an array of objects Is there any way to hide taskbar labels and not combine taskbar buttons? There are three options for customizing taskbar buttons in Windows 7:   Always combine, hide labels Combine when taskbar is full Never combine   Is there any way to hide labels and not combine taskbar buttons? Or even better, to exclude only certain applications from combining?  My main problem is that I switch a lot between two instances of a single application, and having to hover over combined icon and then choosing the correct one. Alt-Tabbing is not a good alternative when I'm switching between more than three applications; clicking on taskbar only once is what I'm looking for. I normally use the following idiom to check if a String can be converted to an integer.  public boolean isInteger( String input ) {     try {         Integer.parseInt( input );         return true;     }     catch( Exception e ) {         return false;     } }   Is it just me, or does this seem a bit hackish?  What's a better way?    See my answer (with benchmarks, based on the  by ) to see why I've reversed my position and accepted  to this problem.  I think this original code will be used by most people because it's quicker to implement, and more maintainable, but it's orders of magnitude slower when non-integer data is provided. My questions is very simple. How can I set security setting for a PDF file created with PDFLatex?  I should set some password or print permissions, etc. Testing AuraHandledExceptions? It seems like when I call getMessage on a thrown AuraHandledException, I see "Script-thrown Exception" instead of the message that I have set. Any idea why this may be happening?  Controller:       @AuraEnabled     public static Conversation__c makeConversation(String tonum, String objid)     {         if (tonum.length() != 10)             throw new AuraHandledException('ToNumber length invalid.');     }   TestController:  @isTest     static void testMakeConversationInvalidTo()     {         Boolean testPass = false;         String fromNumber = '1234567890';         String toNumber = '1';          List&lt;ConversationController.ConversationWrapper&gt; test =    ConversationController.getConversations();         System.assertEquals(0, test.size());         try {             ConversationController.makeConversation(toNumber, '0');         } catch (AuraHandledException e) {             System.debug(e.getMessage());             System.debug(e.getTypeName());             System.assert(e.getMessage().contains('ToNumber length invalid'));             testPass = true;         }     }   Return:  16:26:28:477 USER_DEBUG [320]|DEBUG|Script-thrown exception 16:26:28:477 USER_DEBUG [321]|DEBUG|System.AuraHandledException How to define a bijection between $(0,1)$ and $(0,1]$? How to define a bijection between $(0,1)$ and $(0,1]$?   Or any other open and closed intervals?   If the intervals are both open like $(-1,2)\text{ and }(-5,4)$ I do a cheap trick (don't know if that's how you're supposed to do it): I make a function $f : (-1, 2)\rightarrow (-5, 4)$ of the form $f(x)=mx+b$ by \begin{align*} -5 = f(-1) &amp;= m(-1)+b \\ 4 = f(2) &amp;= m(2) + b \end{align*} Solving for $m$ and $b$ I find $m=3\text{ and }b=-2$ so then $f(x)=3x-2.$  Then I show that $f$ is a bijection by showing that it is injective and surjective. how to fill color in image in particular area? How to Change the Origin when moving a Collection Instance I have created an Collection Instance, when I try to move it, the origin(to snap at vertices or edges) is far away from the object, I want to set it.    In the image, the Collection Instance is selected, the cross is far away from the object and I can´t set it using "Set Origin to 3D Cursor"  What Am I missing? EM with Binomial