Modelling array of holes into mesh
How can I make a hexagonal grill?
Why does println(array) have strange output? ("[Ljava.lang.String;@3e25a5") Computing second partial derivative with polar coordinates Consider the polar coordinates with $x=r\cos\theta$ and $y=r\sin\theta$.  I can show using the chain rule that $$\frac{\partial}{\partial x} = \frac{x}{r} \frac{\partial}{\partial r} -\frac{y}{r^2} \frac{\partial}{\partial \theta}$$   What is the method to compute $\dfrac{\partial^2}{\partial x^2}$? I don't know how to do it. Can I run 64 bit apps in 32 bit Linux? There are some proprietary apps that are being provided only in 64-bit version. Let $S = \{1,2,\dots,n\}$. Then $i \in S$ is said to be a fixed point of a permutation $p$ or $S$ if $p(i) = i$. Let $P_n(k) $ be the number of permutations of $S$ which have $k$ fixed point. Prove that $\sum_{k=0}^nk\cdot P_{n}(k) = n!$. Multiple workspaces on Ubuntu 18.04.1 LTS and later with GNOME Shell Any idea how to have more than 2 workspaces on Ubuntu 18.04.1? How can I update my OpenGL to 3.0 or higher I have updated my kubuntu 14.10 to kubuntu 15.04. And now after boot, when I enter my password on welcome screen, I will get black screen. It's looks like screen powered off. No cursor, no change brightness. Nothing. And when I try switch to text consoles (Ctrl+Alt+F1) nothing happening. If I doesn't login in welcome screen I can switch to text console. Is there a standard way to do an fopen with a unicode string file path? Let's take the numbers 0-10.  Their mean is 5, and the individual deviations from 5 are -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 And so the average (magnitude of) deviation from the mean is $30/11 \approx 2.72$.  However, this is not the standard deviation.  The standard deviation is $\sqrt{10} \approx 3.16$.  The first mean-deviation is a simpler and by far more intuitive definition of the "standard-deviation", so I'm sure it's the first definition statisticians worked with.  However, for some reason they decided to adopt the second definition instead.  What is the reasoning behind that decision? My online friend is asking for money in order to visit my home country. Is this a legit request or a scam? Can we modify "Ask question" to automatically suggests tags based on your question content.   So instead that user needs to type "team-foundation-server" or "TFS" or "TeamFoundationServer" he will see list of tags auto-populated with ajax which he (or she) can then select and it will be associated with the question. So basically only thing we need is code which will cross-match question content with list of known tags while user is typing and display results in some nice ajax-enabled list/cloud/whatever UI control. This should be separate control for tags suggestions so user still has option to use standard tag list input to type-in tags.  In this case, instead of three (or more) tag variations we would have only one tag for Team-Foundation-Server. How to change Blender's default startup settings? How can I change Blender from the default cube/lamp/camera default setup? Also, is it possible to change other features, such as the default view direction (Top, Side, etc) or the Editor type (3D View, Node Editor, Graph Editor, etc)? How do I post code in chat? I would like to be able to post code in chat. I know that I can post inline snippets of code by using backticks, but I don't know how to post blocks of code, with the entire chat message formatted as code, and indentation respected. I am aware of . After reading the comments, I found out that I could format in "fixed width", but I can't see a "fixed width" button anywhere. What should I do? How should an educational institute woo good faculty? How can I output a list of all installed packages with installation date and additional information? I was drinking iced-water from a drinking glass (made of glass) at a restaurant yesterday when I was taking a drink, I noticed that there is very little ice water coming out and then suddenly, the ice water mixture comes crashing down. With my open mouth overfilled with ice water, my shirt gets wet – I hate when this happens. After drying myself off, I started thinking why this does happen:   How does ice that starts off loose and separated in water fuse together to form one large clump? What causes the ice-water mixture to stop flowing momentarily and then suddenly starting flowing again? Is it that the ice fuses together in the glass and forms one large clump, and then the friction with the edges builds a "dam-like" situation? Or are there individual pieces of ice fusing with the edges of the drinking glass damming-up the ice? Checking if a key exists in a JavaScript object? How do I set Titanfall in-game language to English (Russian version)? This question was initially about Russian PC version of Titanfall, available in Russian Origin store.  It appears that there exists a Worldwide PC version of Titanfall for which .  Tech support said that Russian users can only buy Russian version of Titanfall (both normal and Deluxe editions) and that they will not have any other in-game language available. They also offered me a refund, which I accepted.    I'm living in Russia and I recently pre-purchased Titanfall from here. My version doesn't have an option to select game language other than Russian.  Russian version has awful localization, many mistranslated technicalities and poorer game UI fonts than its English counterpart. Titan's on-board AI voice is pretty lame. The campaign briefing lines are cut off to fit the English files' length. Voice actors took liberty to change a few things to their liking. Audio effects like reverberation, echo and such are distinctively more basic. Overall audio quality is much lower, which greatly hinders immersion.  When I was playing open beta, it was all in English and considerably better. The game also doesn't support Russian characters so everyone is using transliteration in chat.  Switching Origin UI language to English didn't change the game's language. It's still all Russian.  How do I change Titanfall UI and audio to English?    Also: the support person didn't explicitly say tampering with localization files was against any rules or policy, so this may or may not be okay to do. Gotta find some hard info on that.  Although, adding launch parameters -language english, -language "english" in case of Russian version does not help. Players with other versions report that it does help.  As can be seen during game installation, the sound files alone take up about ~33 GB of disk space, and according to Origin's solution to Worldwide PC version, these files contain localization for every language available. It's just the rights to access them depend on version.    Note: it's important that the solution does not break any rules and is not outright illegal. Otherwise it may be removed from this site by a moderator, or, in worst case scenario, lead to some player's game and account being locked. So if you post something suspicious looking, be sure to include some links to official statements that allow such actions. How do I convert, NSDate to NSString so that only the year in @"yyyy" format is output to the string? Cannot change lock screen background on Ubuntu 18.04