So, it's in the title pretty much.   The code creates a temp folder Data with loads of intermediate output in it.   I forgot to put that folder in .gitignore, then hit pushed to master and went to sleep. Now the repos is too big by about 1GB. How can I remove these files?
I accidentally committed an unwanted file (filename.orig while resolving a merge) to my repository several commits ago, without me noticing it until now. I want to completely delete the file from the repository history.   Is it possible to rewrite the change history such that filename.orig was never added to the repository in the first place?
I have a  repository which contains a number of subdirectories. Now I have found that one of the subdirectories is unrelated to the other and should be detached to a separate repository.  How can I do this while keeping the history of the files within the subdirectory?  I guess I could make a clone and remove the unwanted parts of each clone, but I suppose this would give me the complete tree when checking out an older revision etc. This might be acceptable, but I would prefer to be able to pretend that the two repositories doesn't have a shared history.  Just to make it clear, I have the following structure:  XYZ/     .git/     XY1/     ABC/     XY2/   But I would like this instead:  XYZ/     .git/     XY1/     XY2/ ABC/     .git/     ABC/ Prove that the equation $x^4+(2k^2)x^2+2k^4$ is not a perfect square What spell targets count for the Graviturgy Magic wizard's Gravity Well feature? The  feature from the  (EGtW, p. 185) triggers &quot;whenever you cast a spell on a creature&quot;, and has an effect &quot;if the target is willing to move, the spell hits it with an attack, or it fails a saving throw against the spell.&quot; It's not clear to me what kinds of spells can actually trigger this feature. Based on the singular phrasing of &quot;on a creature&quot; and the later use of the word &quot;target&quot;, I would normally read this as only applying to spells that explicitly target creatures (and perhaps only those with a single target, in contrast to the phrasing of the  feature of the  wizard, for example). However, spells that target a location can use the word target in a different sense (see ). What's actually going on here? Does this feature only work on targeted spells? Or does it function for area of effect spells as well? Or is this just an ambiguous phrasing that will rely on the DM's ruling? What to do with bounty on question which is no longer relevant? How do you post to an iframe? How do you post data to an iframe? Ideal contained in a finite union of prime ideals Let $I \subset R$ be an ideal and $P_i$  $(i=\{1,...,n\})$ prime ideals with $I\subseteq\bigcup_{i=1}^nP_i$. Prove that then $I$ is contained in one $P_i$.   I don't know how to show this because I don't have any approach.  So I am looking for something to start with or something like a sequence of tips (Since I know this is a large proof)  Thanks in advance! options for appearance of links in hyperref How check if a picklist value is available or not for a specified record type ( through SOQL)? Thanks in advance Suppose $R\neq 0$ is a commutative ring with $1$. Let $M$ be a free $R$-module. I would like to prove that $M$ is a flat $R$-module. Everywhere I have looked (mostly online) this is proved by first proving that every free module is projective, and then proving that every projective module is flat. Unfortunately, Atiyah &amp; Macdonald's "Introduction to Commutative Algebra" (Chapter 2) does not discuss projective modules. But the result that every free module is flat comes very handy in the exercises.   So my question is,     Is it possible to prove that every free module is flat just by   definitions and without appealing to projective modules?   Thanks! Can the Big Rip really rip apart an atomic nucleus? Some scenarios describing the fate of the matter vs  tug of war on the universe involve the acceleration of the universe increasing to the point that it ends up ripping apart even atoms. This is called the .  This makes no sense to me. It looks like all of these   (GR) models of the universe assume it has a uniform isotropic distribution of matter and energy. This works great at long scales, but it is also clearly wrong even at the length scale of the separation of galaxies.  The density of atomic nuclei remains the same even though the universe is expanding even as we speak. I don't think the "scale" in the  can be interpreted so literally. Or maybe said better, it's got to break down when the cosmological horizon distance gets to the scale where the isotropic assumption breaks down, right?  How can scientists be claiming that runaway expansion will rip apart atoms? What are the most common pitfalls awaiting new users? mysql select from n last rows I have a table with index (autoincrement) and integer value. The table is millions of rows long.  How can I search if a certain number appear in the last n rows of the table most efficiently? Has anyone used PostgreSQL with PostGIS successfully?   I am a semi-experienced ArcGIS user and want to build out a database and connect it to ArcCatalog.   I've scoured the internet for resources but nobody has really given a good walkthrough. What happens when you die? Diablo's first and second installments handled death differently, both in terms of exp\gold penalties and also in if you respawned or not or instead had to reload from an earlier point.  In Diablo III what happens when you die? What's the difference between $\mathbb{R}^2$ and the complex plane? I haven't taken any complex analysis course yet, but now I have this question that relates to it.  Let's have a look at a very simple example. Suppose $x,y$ and $z$ are the Cartesian coordinates and we have a function $z=f(x,y)=\cos(x)+\sin(y)$. However, now I change the $\mathbb{R}^2$ plane $x,y$ to complex plane and make a new function, $z=\cos(t)+i\sin(t)$.  So, can anyone tell me some famous and fundamental differences between complex plane and $\mathbb{R}^2$ by this example, like some features $\mathbb{R}^2 $ has but complex plane doesn't or the other way around. (Actually I am trying to understand why electrical engineers always want to put signal into the complex numbers rather than $\mathbb{R}^2$, if a signal is affected by 2 components)   Thanks for help me out! Unable to format internal drive as APFS on 2018 MacBook Pro I’ve recently ran a semi-routine clean install on my 2018 MacBook Pro. This involves the following steps (in the given order):   Creating a USB installer with the latest macOS Mojave 10.14.2. Booting into the USB (Pressing Option key on boot). Using the Disk Utility, erasing the Disk and formatting it as APFS with a GPT Partition scheme. Using the Terminal, unmounting the disk diskutil unmountDisk disk0, where disk0 is the internal NVME drive. Using the Terminal, running gpt destroy disk0 where disk0. Using the Terminal, running diskutil zeroDisk disk0. Once that process is complete, I use the Disk Utility application to reformat as APFS, and install macOS.   Nothing super crazy, maybe a little redundant in steps, maybe a little overkill, maybe a little unnecessary.  Recently, however, on the final step where I format it as a APFS drive, it fails in creating the APFS container and says Internal State Error. It appears to first format as Mac OS Extended (Journaled) then create an APFS container, then add a APFS Volume. It fails when adding a Volume with An internal error occurred.  I have tried many things, including:   Securely erasing the drive diskutil secureErase 0 disk0. Simply zeroing the disk again diskutil zeroDisk disk0 (I’m not sure what the actual difference between these two are). Reformatting the drive as other things, such as ExFAT / FAT / MacOS Journaled, then trying to format as APFS. Reformatting the drive through the command line instead: diskutil eraseDisk JHFS+ NAME disk0 → diskutil apfs createContainer /dev/disk0s2 → diskutil apfs addVolume disk0s2 APFS NAME (It fails here with Error starting APFS Container creation: The given disk is not an APFS Container Reference (-69630), even though I just made a container there. Also, trying to add a volume to where it actually made the container (i don't know what it does this) diskutil apfs addVolume disk24 APFS NAME also fails with Error: -69624: Unable to add a new APFS Volume to an APFS Container Reformatting the drive using this: diskutil eraseDisk APFS NAME disk0 Restarting and trying these again. Using a different installer than the USB (The one from Command + R, Command + Shift + R, and whatever the other combo is), and trying these again.   All end up at the same thing - the final step fails. I would expect especially after a secure wipe that the drive would be removed from whatever state it was put in, or that if it was a bug with the 10.14.2 installer, that it still wouldn’t happen again in the High Sierra installer. In Disk Utility, I’m left with the following structure:  - APPLE SSD AP(...) // “Container disk24” takes up all space      - Container disk24 // or some other number. “Used” is 207.2MB and “Free” is 1TB.   Please note even though I can format as JHFS+, it won’t let me install the OS to such a formatted volume. The installer tells me this computer forces me to only install on APFS formatted volumes.  Any direction is greatly appreciated. I have never had such a silly problem before. Also, note that I have no Time Machine backup. If I have a point which I want to hit at the end or during a parabolic arc, how would I calculate the needed x and y velocity? Reusable functions in jQuery callback Inner join using an array column Having trouble indexing and executing a query in O (log n) time.  The query includes an INNER JOIN, an ORDER BY, and an equality operation. If I understand the laws of databases correctly, a query can be indexed and executed in O (log n) time (or thereabouts) if a non-equality operator is not used on more than one column. In this case, I believe the INNER JOIN does count as an equality operator and the non-equality operator would be the ORDER BY portion of the query. This table has upwards of 10,000,000 rows and needs to handle several reads and writes per second.  Using PostgreSQL. This is what the table looks like. As you can see, the column 'Names' is a list property and it is the column that the INNER JOIN goes against:  Age Names                       Date 34  ['carla', 'john', 'sam']    3/13/2011 26  ['json', 'cindy', 'joel']   3/13/2011 72  ['beth', 'amber', 'susie']  3/13/2011 14  ['john', 'jim', 'debie']    3/13/2011   This is the query that we are trying to do:  SELECT * FROM the_table WHERE Age==26 AND Names=='john' ORDER BY Date   My background is from using App Engine's Big Table, so I've used equality operators here to indicate that 'john' should be one of the names in the Names column. This would be an acceptable query in GAE's big table, it would execute in O (log N) time as all Big Table queries are reqyured to do. I am assuming there is a way to do this in PostgreSQL as well since PostgreSQL accepts list data types as columns.  Is this possible to do in PostgreSQL?  If so, how should the index be set up (we can't figure out how to set up an index that takes into account the three properties)? Installing PHP 5.3 in Ubuntu 14.04 I've just installed Ubuntu 14.04 and am trying to install php 5.3. But when I run   apt-get install php5    it's installing php 5.5.9-1ubuntu4. I need to use php 5.3 in the system because the application I'm working on is built with php 5.3.   How can I achieve this?