Getting filesystem path of class being executed
Find where java class is loaded from
How and when does the tracking of shared links work? How do I write a correct micro-benchmark in Java? Is there a bijective function mapping Natural numbers to Natural numbers, other than $f(n) = n$? Is there a function that can be bijective, with the set of natural numbers as domain and range, other than $f(n) = n$? How do I change my default browser? Is there an option to change my default browser for all my applications? Super+D key shortcut does not show desktop I recently installed Saucy Salamander on my computer. Previously in Ringtail, Super+D used to show the desktop. However for this release, the Super+D does not seem to work properly... Is it a bug? Is there a way for me to download the full list of tags (and synonyms) used on Stack Overflow? My intent is to import these tags into an SQLite database as part of a process to convert all of my delicious bookmarks and tags to the ones used here on Stack Overflow. How to Compact geodatabases in multiple directories using ArcPy? I am trying to write a script to walk through all folders in my workspace and find and compact all geodatabases in my workspace.  I feel like I'm on the right track but I am stuck.  import acrpy, os from arcpy import env  arcpy.env.workspace "C:"  for (path, dirs, files) in os.walk(arcpy.env.workspace)     for file in files         if ".gdb" in file:         workspaces = arcpy.ListWorkspaces("*", "FileGDB")             for workspace in workspaces:             arcpy.Compact_management(workspace)   I am using ArcGIS 10.2.2 for Desktop. How to calculate the summation $(\sum_{p = k}^{n} \binom{n}{p}) / 2^n$ quickly? I was solving a question which technically reduces to the following     Given $N$ items, it is equiprobable for each item to be good or bad, what is the probability that number of good items in the set are greater than or equal to $K$.   This can be reduced to $\dfrac{x}{2^n}$ where $\displaystyle x = \sum_{p = k}^{n} \binom{n}{p}$. Is there a more simplified form which is easier to calculate for large values of $N, K$?  Note: It may be safe to assume that we do not require extremely high precision while calculating(first 5-10 digits only).  Thanks! I'm completing a problem set, one problem for which I literally have no idea what to do on. The graders would prefer to have a physical copy of the problem so I thought it best to include the ¯\_(ツ)_/¯ emoji as my answer, instead of something like "Dunno" or "No idea."  Option #1 is to include an image.  Beyond that I actually don't understand how this emoji works. The middle character is Japanese kana "tsu" and proves problematic - TeX wants it in math mode then renders "?" when it is. Relation between power and energy If I have an expression for the 'rated generator power' of a wind turbine, call it $P(t)$ how is the energy, that the wind turbine generator generate, related to the power $P(t)$?  So: $$E(t)=\dots$$ Will deleting my question also remove the reputation awarded to answerers? One of my questions got closed, as it was very similar to some other posted questions (though I don't feel the linked questions answered what I was trying to ask).  There's no point to the question staying online, as it doesn't answer anything, so I was going to delete it - but if I do that will it remove the reputation of the helpful answerers I want to upvote? Problem with sudo apt update in Ubuntu 18.04: Post-Invoke-Success if /usr/bin/test -w /var/lib/command-not-found/ The terminal gave me these errors when updating the software with sudo apt update.    Hit:1 http://it.archive.ubuntu.com/ubuntu bionic InRelease Hit:2 http://it.archive.ubuntu.com/ubuntu bionic-updates InRelease                                                                                        Hit:3 http://it.archive.ubuntu.com/ubuntu bionic-backports InRelease                                                                                      Hit:4 http://security.ubuntu.com/ubuntu bionic-security InRelease                                      Hit:5 http://archive.canonical.com/ubuntu bionic InRelease                 Traceback (most recent call last):                       File "/usr/lib/cnf-update-db", line 8, in &lt;module&gt;     from CommandNotFound.db.creator import DbCreator ModuleNotFoundError: No module named 'CommandNotFound' Reading packages list... Done E: Problem executing scripts APT::Update::Post-Invoke-Success     'if /usr/bin/test -w /var/lib/command-not-found/ -a -e /usr/lib/cnf-update-db;       then /usr/lib/cnf-update-db &gt; /dev/null; fi'   E: Sub-process returned an error code     These are the results of sudo apt install --reinstall command-not-found  Reading package lists... Done  Building dependency tree         Reading state information... Done 0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded. Need to get 0 B/5.188 B of archives After this operation, 0 B of additional disk space will be used. (Reading the database ... 225797 files and directories currently installed.) Preparations for extracting ... / command-not-found_18.04.4_all.deb ... Extracting command-not-found (18.04.4) on (18.04.4) ... Configuring command-not-found (18.04.4) ... libdvd-pkg: Package libdvdcss2-1.4.2-1 was removed, stop processing...   When I tried the command sudo apt update again after reinstalling command-not-found, the results were the same as described in the first text block. Identity for convolution of central binomial coefficients: $\sum\limits_{k=0}^n \binom{2k}{k}\binom{2(n-k)}{n-k}=2^{2n}$ It's not difficult to show that  $$(1-z^2)^{-1/2}=\sum_{n=0}^\infty \binom{2n}{n}2^{-2n}z^{2n}$$  On the other hand, we have $(1-z^2)^{-1}=\sum z^{2n}$.  Squaring the first power series and comparing terms gives us  $$\sum_{k=0}^n \binom{2k}{k}\binom{2(n-k)}{n-k}2^{-2n}=1$$  that is,  $$\sum_{k=0}^n \binom{2k}{k}\binom{2(n-k)}{n-k}=2^{2n}$$  My question: is there a more direct, combinatorial proof of this identity?  I've been racking my brains trying to come up with one but I'm not having much success. How do I tell which point-and-shoot cameras take good low light photos? I have a Canon Powershot A710 and I previously had a previous Powershot A-series model. I love them due to the high amount of control they offer. Sadly, they both suck in low light conditions, their flash is very unresponsive, and the camera takes several seconds preparing itself for the next shot after a flash shot. And even then, the pictures they take in low light/flash are as bad as good are those with good light.  I'd like a camera which gives a lot of control options, but what do I need to look for to find one that's great in low light, with or without flash? How to prove that if $\forall x \in (a,b)$ Lebesgue integral $\int_{(a,x)}fd\lambda=0$, then $f(x)=0$ $\lambda$-almost everywhere? Let $f:(a,b)\rightarrow\mathbb{R}$.  The statement to prove is that if $\forall x \in (a,b)$ Lebesgue integral $\int_{(a,x)}fd\lambda=0$, then $f(x)=0$ $\lambda$-almost everywhere.  So if it wouldn't be true then we would have $\forall x \in (a,b):\int_{(a,x)}f_+d\lambda=\int_{(a,x)}f_-d\lambda\neq0$, so every interval contains positive and negative values of the function. It is  such an $f$ so my guess would be that this function is not Lebesgue measurable and we can't take this integral.  Thanks in advance! Hint proving this $\sum_{k=0}^{n}\binom{2n}{k}k=n2^{2n-1}$ I need hint proving this $$\sum_{k=0}^{n}\binom{2n}{k}k=n2^{2n-1}$$ How do I calculate the date six months from the current date using the datetime Python module? Empty drives show 2 GB used, Explorer shows nothing I have 4 drives in Windows: C:, D:, E: and F:. Except C:, all of them are empty.    Suddenly it shows up to 2 GB space used – even when there are no files.     [  When I format the drives, it's fine for a while until it shows used space again.  I use Windows 8.1 Pro 64 Bit. Do quest items weigh anything? Someone said that quest items don't count against your carrying capacity in Skyrim, even if they have a weight listed. Is this false? How to find files that contain one criterion but exclude a different criterion