I an array like this  @observable data = [{a: 1}, {b: 1}, {c:1}];  @observable sampleData = [];   I want to do a slice   this.sampleData = this.data .slice(0, 1);  this.sampleData[0].a = 2;    I want "2" to effect the the record in "sampleData" not in the "data" array what is happening now.
What is the most efficient way to clone a JavaScript object? I've seen obj = eval(uneval(o)); being used, but . I've done things like obj = JSON.parse(JSON.stringify(o)); but question the efficiency.  I've also seen recursive copying functions with various flaws.  I'm surprised no canonical solution exists.
Wave states with great confidence that Incursio is weaker than Grand Chariot, because Incursio was a prototype for Grand Chariot, etc.  The early clashes between Wave and Tatsumi can lead the viewer to such conclusion, but Incursio's has the ability to evolve (from the beast it was made of), while Grand Chariot doesn't.  If you watched to the finale, we can see that      Tatsumi causes Incursio to evolve so much during the fight against Shikoutazer that it even gains the ability to fly. While it is enough to defeat the emperor, unfortunately not enough to save Tatsumi's life.   Considering this, I don't think that Incursio was the weaker one. Is it so? "Your python3 install is corrupted" I want to upgrade from Ubuntu 16.04.5 LTS to 18.04, so ran sudo do-release-upgrade. After downloading and extracting bionic.tar.gz I get:  Can not upgrade   Your python3 install is corrupted. Please fix the '/usr/bin/python3' symlink.   I saw  and so I did sudo ln -sf /usr/bin/python3.6 /usr/bin/python3 thinking that it would be a similar problem. But that didn't work (still same error message).  I have a few python versions:  $ ls /usr/lib | grep python python2.7 python3 python3.5 python3.6  $ update-alternatives --display python3 python3 - auto mode   link best version is /usr/bin/python3.6   link currently points to /usr/bin/python3.6   link python3 is /usr/bin/python3 /usr/bin/python3.5 - priority 1 /usr/bin/python3.6 - priority 2   How do I fix python3? What does $\lim\limits_{x \to \infty} f(x) = 1$ say about $\lim\limits_{x \to \infty} f'(x)$? Given that $f$ is differentiable, what does $\lim\limits_{x \to \infty} f(x) = 1$ say about $\lim\limits_{x \to \infty} f^\prime(x)$ ? Intuitively I feel that it's $0$.  I attempted to solve this by trying to evaluate $$\lim_{x \to \infty} \lim_{h \to 0} \frac{f(x + h) - f(x)}{h} $$ by trying to interchange the limits after showing that $\frac{f(x + h) - f(x)}{h}$ converges uniformly as $x \to \infty$. But I couldn't proceed further.  Trying to work backwards, as a specific example, $f(x) = \arctan(x)$ came to my mind. It's derivative certainly goes to $0$ as $x \to \infty$. Doesn't this show that $\frac{f(x + h) - f(x)}{h}$ converges uniformly to $0$ as $x \to \infty$ ?  I'm totally confused! I would really appreciate if anyone told me what I am doing wrong. Can a character escape the  (DMG p. 177, listed in the SRD as the ) with the  spell? To clarify, I am not asking if the bands prevent teleportation. I am asking whether the bands are teleported with the character as he teleports using misty step. Diff is a great tool to display the changes between two files. But how to display the similarities of two text files (while ignoring the differences)?  I.e. sample input:  a: Foo Bar X Hello World 42  b: Foo Baz Hello World 23   Pseudo output (something like this):  @@ 2,3 =Hello World   Just sorting both files and using comm is not enough, because in that case the line information is lost. Fixed background image with ios7 undelete big files - mission impossible? I've accidentaly deleted outlook.pst (6.7GB) file, while there was only 400MB free space left on primary NTFS partition (winxp).  I've tried several recovery tools to get this file back. "Ontrack Easy Recovery Pro" found 0 pst files (complete scan mode), while "Recover My Files" in sector scan mode found 5 pst's, but 4 of them of sizes from 3 to 28 KB, while the 5th one - 1Gb.  I've managed to succesfuly recover 1Gb pst file, which was 1 year old copy (the one used after the latest windows reinstall).  Now, I'm frustrated and confused   Why 1 year old file was succesfuly recovered if there were only 400MB left on primary partition? Where's 6.7GB file gone? I did some reading (), and it seems that there's almost no probability to retrieve the file I'm looking for, but wait - none of recovery tools i've used found zero-sized pst file, moreover - if due to fragmentation a file might be corrupted - we could use scanpst.exe to fix some errors and survive with 10 or 100 emails missing - whatever. Could you please recommend some more sophisticated recovery tools for this particular task?   Appretiate your help - thanks in advance How to twist radial vector to make spirals? 'pyrcc4' is not recognized as an internal or external command? C:\Users\Department\.qgis2\python\plugins\np&gt;pyrcc4 -py2 resources.qrc -o resources.py      'pyrcc4' is not recognized as an internal or external command,      operable program or batch file.   How do I solve this problem? Outlier Detection on skewed Distributions Under a classical definition of an outlier as a data point outide the 1.5* IQR from the upper or lower quartile, there is an assumption of a non-skewed distribution. For skewed distributions (Exponential, Poisson, Geometric, etc) is the best way to detect an outlier by analyzing a transform of the original function?  For example, distributions loosely governed by an exponential distribution, could be transformed with a log function - at which point is it acceptable to look for outliers based on the same IQR definition? Proving the set of points at which a function diverges to $\infty$ is countable Let $f\colon\mathbb{R}\to\mathbb{R}$. Prove that the set    $$\{x \mid \mbox{if $y$ converges to $x$, then $f(y)$ converges to $\infty$}\}$$ is countable.   My book told me to consider  $g(x)=\arctan(f(x))$, then it said "it is easy to see the set is countable." But I still can't understand what it mean. In Windows I used command-line clipboard copy-and-paste utilities...      pclip.exe and gclip.exe     These were UnixUtils ports for Windows (but they only handled plain text). There were a couple of other native Windows utilities which could write/extract any format.    I've looked for something similar in Synaptic Package Manager, but I can't find anything.    Is there something there, that I've missed? ... or maybe this is available in Bash scripting?    The type of utility I'd like will be able to read/write via std-in/std-out or file-in/file-out, and handle Unicode, Rich Text Format, picture, etc. clipboard formats...    NB: I'm not after a clipboard manager. There are so many questions on this website. There is so many questions on this website.  The former &quot;sounds right,&quot; but the contracted form of the latter does as well:  There's so many questions on this website.  Which is correct? I was wondering if quantum particles do actually  exists in two different states simultaneously and if it has been proven they do indeed exists in a superposition of states.  How has it been figured out since observing it would collapse the wave-function into one single state (two superposition of states into one ) as it has been mentioned in the Schrodinger's cat experiment? What is the purpose of a serial number? What's the difference between "cardinal" and "ordinal" as adjectives? Is there a way for non-root processes to bind to "privileged" ports on Linux? It's very annoying to have this limitation on my development box, when there won't ever be any users other than me.  I'm aware of , but none of them do exactly what I want:    (The version in Debian testing, 1.0, only supports IPv4)  (the "nat" table is not yet implemented for ip6tables, the IPv6 version of iptables) sudo (Running as root is what I'm trying to avoid) SELinux (or similar). (This is just my dev box, I don't want to introduce a lot of extra complexity.)   Is there some simple sysctl variable to allow non-root processes to bind to "privileged" ports (ports less than 1024) on Linux, or am I just out of luck?  EDIT: In some cases, you can  to do this. Modiagram will not compile How is an empty set truly "empty"? In a  question, an answerer says:  an empty bag is a bag with nothing inside it.  Makes sense, but I'm reading a textbook right now that says:  The empty set has only one subset (namely, itself).  Which seems odd to me. If a set is empty, why would it contain a subset? Regardless of whether or not the subset is also an empty set, the &quot;empty set&quot; still contains a subset, so how is it really &quot;empty&quot;? To go back to the empty bag analogy, it just sounds like my text book is saying:  an empty bag is a bag with nothing but an empty bag inside it.  Which doesn't make sense because then the bag isn't empty. I can't wrap my head around this concept. Linux Bulk/Remote Administration Beside our internal IT infrastructure, we've got around 500 Linux machines hosting our services for the on-line world. They are grouped in a bunch of clusters like Database A-n, Product A-n, NFS, Backoffice and so on. Furthermore, they are administered by an external provider, according to our specifications and requirements.  However, we face a lot of trouble during (web-) software development, roll-out and deploy - especially because the dev- and staging-environments have almost nothing in common with the live systems (I spare out the nasty details..).  Thus, I've tried to create virtual machines, copied the various live-systems as exactly as possible and prepared them to connect to e.g. the development-databases instead of the "real" ones transparently for developers (they aren't root). This works pretty well, but...  I was wondering how one could administer those systems remotely and in bulk? Is there some software family I'm not aware of? Or, at least, some techniques or principles one should be familiar with?  We would provide every developer with a bunch of images to be run locally (VirtualBox). The QA dept. would get virtual clusters (XEN or Hyper-V). If I need to provide an additional server-module, re-route a new database connection or just want to update everything provided by the package manager... how could I possibly do that without being forced to log on to every system and/or ask my colleagues to download and run some fixture-script?  I believe there are plenty of solutions. Well, somehow I'm too stupid to enter the correct keywords into the search engines... Or isn't this issue as trivial as it sounds?  For the record:   Almost all systems are running Debian GNU/Linux 6.x "squeeze" No developer is forced to use a particular OS at his/her workstation The budget is limited, of course, but not too small to buy proprietary software A solution that would involve our aforementioned provider is preferred