Why are geoalgorithms missing from QGIS processing toolbox (GRASS & SAGA)
Activating 'missing' standard GRASS utilities in QGIS Processing toolbox
How to prevent freehub body damage? I feel like this is poor design. I have two wheelsets that are less than a year old which have damaged freehub bodys due to cogs digging in to the splines on the freehub. It's so bad that I can't remove the cassette spacer without filing down the splines. I had to use  pliers and chain whip to remove the cogs that were embedded in the freehub when trying to remove the cassette.  Most of the damage is on the center of the cassette as the largest 3 cogs are held together by carrier. I'm using a shimano 105 cassette and  Novatec disc hub and Velocity ATB convertible disc hubs (which were somewhat damaged in the same fashion, but not as bad as the novatec).  I'm using this bike for cyclocross, offroad exploring, light singletrack use, Rail trails and some road riding.    How can I prevent this damage to the freehub from happening? Agreeing on a single shortened nomenclature? I've noticed across various stack exchange sites that when they refer to their own stack exchange on their site, they'll shorten the name to something similar to either:  EE.SE (Electrical Engineering Stack Exchange) OR Tex.Sx (LaTeX Stack Exchange)  Essentially they'll do XX.SE or XX.SX which has the possibility to generate some confusion for new users.    Have I not visited enough sites and just noticed an outlier or would it be beneficial for Stack Exchange sites to agree on a shortened name nomenclature? I have to move a MongoDB Collection (Size: 1TB+) from Sharded MongoDB Cluster to another[5 shards on both clusters]. During this operation, it is assumed that the accompanying program will be offline, so no need to worry about inconsistent data, but I need to minimize the downtime.  I've tried testing it with mongodump and mongorestore, but looks like that is taking ages to finish.  Please share your experiences for such kind of scenarios.  Note: Cluster has only one collection, so I am open at cluster level sync as well. notify-send not working under ssh "There are currently N bounties, worth X reputation" dynamic ad and the new sidebar width You've probably seen this sidebar ad on one or more -enabled Stack Exchange sites over the years:    The image is dynamically generated from a non-officially SE app that uses the Stack Exchange API to fetch the bounties from a given site.  As far as I understand, the rendered image automatically scales to the allotted ad space - when the sidebar ads were 220x250, it would render in the sidebar as a 220x250 image while still looking quite oversized in the  meta (as it does right here).  With the new 2016 campaign starting, can we test whether this awesome dynamic ad works with the new sidebar width? How do I force a column-break in a two-column document? I am trying to install php curl like so:  sudo apt-get update sudo apt-get install php5-curl   But I keep getting an error.  Reading package lists... Done Building dependency tree        Reading state information... Done php5-curl is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded. 2 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] Y Setting up runit (2.1.2-3ubuntu1) ... start: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused dpkg: error processing package runit (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of git-daemon-run:  git-daemon-run depends on runit; however:   Package runit is not configured yet.  dpkg: error processing package git-daemon-run (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                           Errors were encountered while processing:  runit  git-daemon-run E: Sub-process /usr/bin/dpkg returned an error code (1)   when I try sudo dpkg --configure -a I get:  dpkg: dependency problems prevent configuration of git-daemon-run:  git-daemon-run depends on runit; however:   Package runit is not configured yet.  dpkg: error processing package git-daemon-run (--configure):  dependency problems - leaving unconfigured Errors were encountered while processing:  git-daemon-run   when I try sudo apt-get install --reinstall runit I get:  Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 8 not upgraded. 2 not fully installed or removed. After this operation, 0 B of additional disk space will be used. E: Internal Error, No file name for runit:amd64   when I try sudo apt-get install runit I get:  Reading package lists... Done Building dependency tree        Reading state information... Done runit is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 8 not upgraded. 2 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] Y Setting up runit (2.1.2-3ubuntu1) ... start: Job is already running: runsvdir dpkg: error processing package runit (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of git-daemon-run:  git-daemon-run depends on runit; however:   Package runit is not configured yet.  dpkg: error processing package git-daemon-run (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                                                                                                           Errors were encountered while processing:  runit  git-daemon-run E: Sub-process /usr/bin/dpkg returned an error code (1)   when I try sudo apt-get install --reinstall git-daemon-run I get:  Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 8 not upgraded. 2 not fully installed or removed. After this operation, 0 B of additional disk space will be used. E: Internal Error, No file name for git-daemon-run:amd64   How can I fix this?  System Specs:  Processor: Intel® Core™ i7-3630QM CPU @ 2.40GHz × 8 Graphics: Gallium 0.4 on AMD TURKS (DRM 2.43.0, LLVM 3.6.2) OS Type: Ubuntu 15.10 64-bit Ubuntu 16.04 Jan 3 2018 update causing screen/access issues Yesterday (Jan. 3, 2018), I installed an OS update (Ubuntu 16.04), using the Software Center. My system isn't working correctly now. When my mouse rolls over the Launch bar, it disappears, then any open window disappears, leaving me with only the desktop screensaver showing. I can't even shut the computer off using the settings button on the top.  I went into the Terminal and attempted to fix it using the following commands:  sudo apt-get dist-upgrade sudo apt-get autoremove   But I'm still having the same problem.  I have reinstalled Ubuntu 16.04 and when I accepted the update on install had the same problem.  I have reinstalled it a second time but have not done an OS update and everything seems to be working fine.    Found another user with the same problem:    Is it possible that the Meltdown security update is at fault?  I've read the update has been issued for 64-bit x86 architecture ();  I'm running a 32 bit i386 architecture.  Could that be an issue and is there a way to correct it? Correct way to use include and includeonly when writing a large document like a thesis I thought of this a while ago, but can't make up a proof or a counterexample. Does anyone know more about this?  $$\sqrt{a+b}  \le \sqrt a + \sqrt b , \forall a,b \in \mathbb R_+$$  Moreover, what happens with more variables? Say:  $$\sqrt{x_1+x_2+...+x_n} \le \sqrt x_1 +\sqrt x_2 + ... + \sqrt x_n $$  with $ x_i \in\mathbb R_+ \forall i \in \{1,2,...,n\} $  Or when $i = \mathbb N$  PS: I tried looking on the internet for this but I don't know how I would call this. What is information? How to understand dot product is the angle's cosine? How can one see that a dot product gives the angle's cosine between two vectors. (assuming they are normalized)  Thinking about how to prove this in the most intuitive way resulted in proving a trigonometric identity: $\cos(a+b)=\cos(a)\cos(b)-\sin(a)\sin(b)$.  But even after proving this successfully, the connection between and cosine and dot product does not immediately stick out and instead I rely on remembering that this is valid while taking comfort in the fact that I've seen the proof in the past.  My questions are:   How do you see this connection? How do you extend the notion of dot product vs. angle to higher dimensions - 4 and higher? (Note that I have used bold text frequently simply to highlight the key points of my question for those who do not have the time to read through it thoroughly (it is not very long, however); I hope this is not considered offensive.)  There are many textbooks on multivariable calculus. However, some textbooks on multivariable calculus do not focus very much on the theoretical foundations of the subject. For example, a textbook might state a result along the lines of "the order of partial differentiation is immaterial" without proof and ask the student to use this rule to solve problems. Similarly, theorems such as those due to Green and Stokes are often not proved in their full generality.   Therefore, I ask the following question:      What are some good theoretical   multivariable calculus textbooks?   Since "theoretical" is somewhat ambiguous, let me state the following criteria which I would like a "theoretical" textbook on multivariable calculus to satisfy:   The textbook should be rigorous and it should not state a theorem without proof if the theorem is proved in at least one other multivariable calculus textbook. (Of course, the textbook may omit certain theorems; however, this criterion at least ensures that major theorems in multivariable calculus are not stated without proof and used purely for the sake of computations. Also, this criterion permits the textbook to state an interesting theorem if it is beyond the scope of all multivariable calculus textbooks.) The textbook should be primarily based on developing the theoretical foundations of multivariable calculus; therefore, applications such as learning how to compute the partial derivative of a function, learning how to solve extremum problems, learning how to compute etc. should be kept to a minimum. In particular, the textbook can assume that the reader has already seen at least an informal treatment of the subject where these aspects are emphasized. The textbook should have a rigorous treatment of differentiability in $n$-dimensional Euclidean space (e.g., the inverse and implicit function theorems should be proven), Riemann integration in $n$-space, and differential forms (e.g., Stokes theorem should be proven). It would also be a bonus if the book treated the general concept of a manifold. Textbooks with minimal prerequisites are preferred; however, please feel free to suggest books meeting the above criteria even if the prerequisites are quite demanding. Finally, it would also be preferable, but not essential, for the book to only treat multivariable calculus.   Examples of books meeting the above criteria: "Analysis on Manifolds" by James Munkres, "Principles of Mathematical Analysis" by Walter Rudin, and "Calculus on Manifolds" by Michael Spivak.   Although I have studied theoretical multivariable calculus already (four years ago), I could never find "the perfect book" (relative to myself, of course). Every book has its virtues; Rudin for its elegance, Munkres for its beautiful exposition, and Spivak for its "quick and dirty" approach. I am hoping that someone will be able to suggest a book that (relative to myself) is "perfect". Also, this question can be useful to other students who have not yet studied the subject and wish to learn it.   Thank you very much for all answers! Please do feel free to suggest as many books as you can think of so we can form a big list. Also, please try to explain why a particular book is good or at least why you think it is good. I suppose it is fine to suggest a book that is already suggested provided you have a different view as to why the book is good. Gray cone obscuring/clipping the 3D Viewport How do I hide posts matching my ignored tags? Where and how do I go about hiding the posts that match any of the tags on my ignored list? Pass PHP variables to Javascript/jquery Remove array element based on object property $dx$ appears in differential equations, such us derivatives and integrals.  For example, a function $f(x)$ its first derivative is $\dfrac{d}{dx}f(x)$ and its integral $\displaystyle\int f(x)dx$. But I don't really understand what $dx$ is. How can I explain how to play D&D to new players without them falling asleep from boredom? Some of my friends just started playing Dungeons &amp; Dragons [5e] for the first time and don't know anything about how to play. I have tried explaining to them the things that are completely necessary and teach them the rest while playing but I could not get them to understand. None of them have a players handbook and they can't afford one and they really want to play. I really want a simple way to explain the basics and since I have a habit of explaining things in ways that are much too complicated. I have already told them the basic rules so all I need to know is a simple way to explain how to play. "There is no point in" or "There is not a point in" I was thinking about these negations. Do these mean the same thing?     There is no point in ...   There is not a point in ...   or:     I have no clue   I do not have any clue     etc.