Trying to get session id in a batch/queueable apex
Session_ID_Remove Issue in API callouts in Salesforce
How to make a "reflective tape" material in cycles? How can I make a cycles material that gets very bright when a light is shown on it, yet still has normal colors? I'm talking about the "" that can be seen on road signs, the tape on big trucks (like in the image below), traffic barricades and clothing.  Image by TollGroup on    This reflective stuff has a interesting property where the colors show up perfectly well, but when exposed to a light source they seem to reflect much more light the normal.  has lots of good reference images.  I have tried different combinations of glossy and diffuse shaders, but none work as I have yet to get the super bright reflections.  How can cycles make a material that reflects so much light, and keeps the colors correct? Suppose that $X_1,X_2,\ldots,X_n$ is a random sample from a distribution with probability function:  $$p_X(x)=\begin{cases} 1/2 &amp;x=-1,1 \\ 0 &amp; \text{otherwise} \end{cases}$$  Now if we define the average   $\bar{X}= \frac{1}{n} \sum X_i$, I need to show that that for an odd $n$ the probability function for $\bar{X}$ is:  $$p_{\bar{X}} (x)= \frac{\binom{n}{\frac{n}{2} (x+1)}}{2^n}$$ for $x=\pm 1/n,\pm 3/n,\ldots,\pm 1$, $0$ otherwise.    Since $P[\sum X_i=k] =P [\bar{X}=k/n ]$, I thought it would be easier to first derive the probability function for the sum. Since they are still $2^n$ n-tuples and each one is equilikely, I need to count the ones whose sum is $k$ for:  $k=\pm 1,\pm 3,\ldots \pm n-2,\pm n$ (since even numbers are not a feasible combination)  The problem here though is that I do not immediately recognize how I could count all these tuples. Could you please help me with this? If it is easier to proceed another way, I am of course all ears. Is the Macbook 12 inch's USB-C charger interchangeable with other USB-C chargers or devices? If there is only the Macbook 12 inch USB-C charger nearby, can it be used to charge other USB-C devices, such as any Android phones that also use USB-C? (will it be "too powerful" and damage other devices?)  Vice versa, if there is a Quick Charge 2.0 or 3.0 USB-C charger from other devices nearby, can it be used to charge the Macbook 12 inch?  The main concern is about whether it could damage the device or battery. OS: Ubuntu 12.04  Accidentally deleted dpkg. Now, packages can't be installed. So, needs an dpkg installer which installs packages. How can I play sound in Java? I want to be able to play sound files in my program. Where should I look? Dimensioning of a technical drawing in TikZ It's a standard result that given $X_1,\cdots ,X_n $ random sample from $N(\mu,\sigma^2)$, the random variable $$\frac{(n-1)S^2}{\sigma^2}$$ has a chi-square distribution with $(n-1)$ degrees of freedom, where $$S^2=\frac{1}{n-1}\sum^{n}_{i=1}(X_i-\bar{X})^2.$$ I would like help in proving the above result. Thanks. Does one work in or on an aeroplane? In an exam paper, there was a picture of an air stewardess in the aeroplane serving passengers. One of my pupils wrote the following:      The air stewardess works on an aeroplane.    Shouldn't it be the air stewardess works in an aeroplane? Now that Apple has removed the ability to access the iOS App Store in iTunes 12.7 on Mac/Windows , I can't find any way to download an IPA file from the App Store. As a note, I'm not worried about installing the IPA files (see ), I just need the IPA files as a developer looking for some basic information on the apps. I'd like to solve this without resorting to jailbreaking as my devices are already updated to iOS 10.3.3.  Here are things that I've tried that didn't work:   Extract from backup: The apps seem no longer to be backed up. Save to Mac from iPhone management software: I believe this has been blocked by Apple works as far back as iOS 8.3. Figuring out how the file is downloaded via proxy connection: At least for me, this looks too complicated to do because you have to authenticate with your Apple ID and I'm sure that by now, Apple even requires the phone to be authenticated in some way. Not sure if it would even be possible in the same way that you see all those Android APK download services out there.   At least for now, it looks to me like maybe the only way is to hold onto an older version of iTunes for as long as that works. Rethrowing exceptions in Java without losing the stack trace Why does pressing a transform hotkey not display the axes on the selected object? I open Blender 2.80 (official release, not a beta or RC) and get the new scene with the usual 3 objects present (camera, light and cube). I select the cube, press 't' for the tools menu and click on the Move tool. The usual 3 axis glyph appears at the cube's origin as expected. But if I use the hotkey 'g' to activate the move transform instead of selecting the tool from the menu with the mouse this glyph does not appear. The exact same problem exists if I use the a hotkey for rotate or scale as well. Why? Is there some clickable checkbox setting hidden somewhere that could have disabled this? Why is my StackOverflow with an indent and doesn't have reputation Book: Handful of children kept in a school as political mythological prisoners Splitting all lines in layer at vertices using QGIS I want to automatically split all lines in a QGIS layer at their vertices (). I've done a Google search and found , which is quite close but the workflow is complicated. Because I'll have to train my co-workers (who are unfamiliar with GIS) to use this tool, I want something as simple as a plugin or something that doesn't require GRASS. Since it's been a long time from 2010 - the time of , I wonder if there is any better way to achieve the same result? A club has $12$ members. They need to choose a programming team of $3$ members and a hacking team of $4$ members. Members can be on both teams, but Jack only wants to be on at most one team. How many ways can both teams be chosen?  I did two different ways. I solved if Jack chooses programming, $C(12,3)=220$ $C(11,4)=330$. In total there are $550$ different ways both teams can be picked.  But, if Jack chooses hacking, I solved $C(11,3)=165$ and $C(12,4)=495$. In total there are $650$ ways both teams can be chosen.  I was wondering if this is the correct method. Setting "checked" for a checkbox with jQuery I'd like to do something like this to tick a checkbox using jQuery:  $(".myCheckBox").checked(true);   or  $(".myCheckBox").selected(true);   Does such a thing exist? How to rename a group of files with what looks like a Windows file path in their names I got a bunch of files with the filename messed up. All the file names have the same beginning which appear to be windows file directories. The problem is there are 700+ files and I really don't want go through and manually rename all of them. These are examples of the file names (Note: None of these have file directories):  G:some\really\long\file\path\then\the\name1.jpg G:some\really\long\file\path\then\the\name2.png G:some\really\long\file\path\then\the\filename.txt G:some\really\long\file\path\then\the\file_name.mov ...   The important take away is that each file has G:some\really\long\file\path\then\the\ before the file name that I would like.   So I would want the above files to look like:  name1.jpg name2.png filename.txt file_name.mov   I've tried the rename command and was not successful. I am still new with Linux and really am not sure on how to go about it or really what to google. Any help would be appreciated. Retrieving Wikipedia's coordinate information? I'd like to add icons to my map showing locations which have Wikipedia entries.  The  is a great resource for determining Wiki entries near an XY location, but it has limitations (20km radius, 50 points only) which make it unsuitable for my purposes.  Ideally I need the map to show ALL locations with Wiki entries, so I guess I'll need to download the Wikipedia dump file and parse it for geocoded entries.  Where is this information found in the Wikipedia dump files?  The Wiki database may be downloaded from  but I can't see which file(s) I need to search for the coordinates.  For example, the  includes:  Coordinates:    33°51′35.9″S 151°12′40″E   Where is this found in the dump files? Another way to phrase the question is "how can I determine which Wiki entries are geo-coded?" Solving minimization problem $L_2$ IRLS (Iteration derivation) In the article ''' Chartrand, Rick, and Wotao Yin. "Iteratively reweighted algorithms for compressive sensing." Acoustics, speech and signal processing, 2008. ICASSP 2008. IEEE international conference on. IEEE, 2008. '''  It is given that one iteration of  iterative reweighed least squares problem can be written as $\min \sum_{i=1}^N w_i u_i^2 $ subject to $\Phi u = b  $ which has a closed form solution given as   $u^{(n)} = Q_n \Phi^T (\Phi Q_n \Phi^T)^{-1} b$. where $Q_n$ is the diagonal matrix containing entries $1/(|u_i^{(n-1)}|^2 + \epsilon )^{1/2} $ And the closed form equation can be derived from the Euler Lagrange equation. Can someone please help me to get the derivation of the iteration?\ I understood till $$\min_u u^TWu+λ|| \Phi u−b||_2^2 $$  which can be written as $(\bigtriangledown=0)$ which gives $$ W u + \lambda (\Phi^T \Phi u - \Phi^T b) =0$$ How do I upgrade an iPhone 4 from iOS 7.1.2 to iOS 8 or 9 I have an iPhone 4 and I need to upgrade from 7.1.2 to iOS 8 or 9. I would like to ask how I can get iOS 8.