I’m loading a JSON file a reading the values into an array using a for loop   I’m concerned that sometimes the JSON file might become corrupted ie the values Im reading in might become ASCII letters ie 1t3 where the value should of been 123   Is there a test case where you could say if values[a]  does not equal a number then set it to “   “ or blank   Thanks,  Ben
What's the cleanest, most effective way to validate decimal numbers in JavaScript?  Bonus points for:   Clarity. Solution should be clean and simple. Cross-platform.   Test cases:  01. IsNumeric('-1')      =&gt; true 02. IsNumeric('-1.5')    =&gt; true 03. IsNumeric('0')       =&gt; true 04. IsNumeric('0.42')    =&gt; true 05. IsNumeric('.42')     =&gt; true 06. IsNumeric('99,999')  =&gt; false 07. IsNumeric('0x89f')   =&gt; false 08. IsNumeric('#abcdef') =&gt; false 09. IsNumeric('1.2.3')   =&gt; false 10. IsNumeric('')        =&gt; false 11. IsNumeric('blah')    =&gt; false
How to extract the n-th elements from a list of tuples? Cohen's d for 2x2 interaction I have a significant 2x2 interaction in a between-subjects design.  I would normally report omega-squared as my effect-size measure, but I've been asked to provide Cohen's d instead?  Can Cohen's d be computed for an interaction?  If so, how? Hide Accesibility icon from Panel I have Ubuntu 18.04 and set the Scaling Factor in Tweaks to 1,10 because the 1920x1080 resolution makes stuff on my screen look a bit too small for my taste. That toggled this stickman icon, which now seems to not want to go away from my Panel unless I disable "Large Text".    Is there any way to hide this icon while keeping my settings? There is a $C > 0$ such that $\vert f(z)-f(w)\vert \leq C\vert z-w\vert$ for a holomorphic map into $B(0, R)$. Let $0&lt;\delta&lt;r$ and $R&gt;0$, and $a\in\mathbb C$. I want to show that there exists $C&gt;0$ such that for all holomorphic functions $f\colon B(a,r)\to B(0,R)$, we have $$ \vert f(z)-f(w)\vert\leq C\vert z-w\vert $$ for $z,w\in B(a,\delta)$.  I'm not sure how to approach this. I was wondering if I could use that $$ \left\vert\frac{f^{(n)}(a)}{n!}\right\vert\leq\frac{\Vert f\Vert_{C(a,\rho)}}{\rho^n} $$ for some $0&lt;\rho&lt;r$. I also have an expression from biholomorphic maps from $B(0,1)$ to itself, but I'm not sure if I could use that here. Any hints? As an example, consider the two sentences:     There don't seem to be any doctors here.   and     There doesn't seem to be any doctors here.   To my ear, the first sounds great, and the second is painfully awkward.  So which is correct, grammatically? I've found lots of disagreement on this around the Web, with various sources citing different ways of treating the word "any" (as singular, always, or as either depending on to what it refers). No consensus, however, could I locate. Has anyone had success recovering deleted files from an ext4 partition? I've tried various utilities, but none have worked yet. I'd be grateful if someone can share a success story! When should unions be used? Why do we need them? Locking a vehicle bicycle rack We are planning a trip with a bike rack attached to our trailer hitch. What is the best way to lock the bikes while the vehicle is unattended? I see some racks have locks on the knobs but they don't seem very strong.   What do you suggest? Prevent Photos app on OSX from launching when plugging in device The Photos app opens whenever I plug in my phone.    How can this be prevented?  I have seen many solutions for the old iPhoto app that involve changing the "Connecting camera opens" option, but the new app has no such option. How to install qt 4.8 from repository? How to install qt 4.8 and QtCreator from repository ? Why on the first page Google says there are thousands of results but on the last page there are less than a hundred? Can I say: I have not gone to the cinema for a long time I already know how to do it on Mac OS X (plenty of instructions online).  But is it possible to do it on Ubuntu? If yes, how? Show that $[0, 1)\times[0, 1)$ is homeomorphic to $[0, 1]\times[0, 1)$ but not to $[0, 1]\times[0, 1]$. When I sketch these spaces it this statement makes sense intuitively because $[0, 1]\times[0, 1]$ is closed and $[0, 1)\times[0, 1)$ and $[0, 1]\times[0, 1)$ are each "missing" part of their boundary which would make them closed. I also know, $[0, 1]\times[0, 1]$ is compact and compact spaces are not homeomorphic to non-compact spaces.   I am having trouble saying this explicitly, as is pretty obvious in the clumsiness of the wording above. Editing network interfaces without system rebooting I'd like to make some changes to my networking configuration by editing my /etc/network/interfaces file. What's the cleanest way to make changes to this file and have them take effect, without having to reboot? Typically, I've been doing:   Edit the file service networking restart   But I have the impression that this isn't the "right" way to make these kinds of changes. Selecting the Real Analysis Textbooks I am a sophomore in US with double majors in mathematics and microbiology. I am interested in self-studying the real analysis starting now since it will help me on my current research on computational microbiology, prepare for upcoming math research (starting on this Fall) on the analytic number theory, and prepare for the real analysis course I will take on Fall and Putnam competition. I just finished "Calculus with Analytic Geometry" by G. Simmons, "How to Prove It" by Daniel Velleman, and "How to Solve It" by G. Polya. I also read some portions of Apostol's Calculu Vol.I to get a deeper view on the calculus theories. I was originally planned to read Apostol's Calculus Vol.I and Spivak's Calculus first, but I think it would be a better idea to start with real analysis since it covers all ideas in those "advanced calculus" textbooks and much more. My current plan is to start with one "dumbed-down" real analysis textbook and one "comprehensive, detailed, and intermediate" textbook, and advance into Rudin's PMA (required textbook for my real analysis course) starting on Summer and use it in accordance with other real analysis textbooks. Could you help me on selecting one book from each category?   Elementary Real Analysis textbooks:  **Elementary Analysis: The Theory of Calculus (Kenneth Ross)  **Understanding Analysis (Steven Abbott)  **The Way of Analysis (Robert Strichartz)  **Real Mathematical Analysis (Charles Pugh)   Intermediate, detailed Real Analysis textbooks:  **Mathematical Analysis (Tom Apostol)  **Undergraduate Analysis (Serge Lang)  **Introduction to Real Analysis (Bartle, Sherbert) **Elements of Real Analysis (Bartle, Sherbert)  **Mathematical Analysis I (Vladimir Zorich)   Thank you very much for your time, and I look forward to your advice!   Sincerely, PK I know it is so weird, but last night I set an image on my desktop background and delete the image, then I right-click on the desktop and press the desktop properties to change the style of background (center, stretch and etc) then the desktop properties stopped something like hanging on Windows.   Then a black window alerted something and I press yes without reading it. after that with right-click on the desktop I just see this:    Even some system applications don't work now. for example, I cannot take a screenshot.  Also, my pcmanfm-qt is dead completely, with the command line or clicking on the icon nothing happens.  I don't know what happens. and I have no idea how to fix it. If $S_n$ has cyclic subgroups of these orders or not? This question was asked in my quiz and I am having difficulties in solving it .  Question : For a positive integer $n$ , let $S_n$ denote permutation group on $n$ symbols. Choose correct statements from below. (a) For a positive integer $n$ and for every $m$ with $1\leq m \leq n , S_n $ has a cyclic subgroup of order $m$; (b) For every positive integer $n$ and for every $m$ with $n&lt;m &lt;n!$, $S_n$ has a cyclic subgroup of order $m$; (c) There exists positive integers $n$ and $m$ with $n&lt;m&lt;n!$ such that $S_n$ has a cyclic subgroup of order $m$; (d) For every positive integer $n$ and for every group $G$ of order $n$, $G$ is isomorphic to a subgroup of order $S_n$ .  Attempt: (a) is true as I can choose an element of length $m$ which will generate cyclic subgroup of order $m$. (b) Choose $n=4$ and $m=19$ to contradict (b). (c) I dont know if there can be found any such case and if yes how to do so . (d) I dont know about it . kindly tell. Answer:   A,C,D are true I am stuck in a question where energy conservation is failing and momentum conservation is correct. I think I might be doing something wrong, that's why I'm asking this question. The problem is as follows:     A bullet of mass $25\,g$ is fired horizontally into a ballistic pendulum of mass $5.0\,kg$ and gets embedded in it. If the centre of pendulum rises by a distance of $10\,cm$, find the speed of the bullet.   (H.C. Verma, Centre of Mass, Q47)     Let the mass of the bullet be $m=25\,g$. Let the mass of the pendulum be $M=5\,kg$. Let the peak height be $h=0.1\,m$. Let the initial and final velocities be $u$ and $v$ respectively.  Method 1: (Momentum Conservation)  $$mu=(M+m)v \implies v=\frac{mu}{M+m}\\ \text{Also, }\frac{1}{2}(M+m)v^2=(M+m)gh\\ \implies u^2=2\biggl(\frac{M+m}{m}\biggr)^2gh\\ \implies u=201\sqrt2 \text{ m/s}$$  Method 2: (Energy Conservation)  Since both the masses move together after the collision, and because the velocity at highest point is null, therefore: $$\frac{1}{2}mu^2=\frac{1}{2}(M+m)v^2=(M+m)gh\\ \implies u^2=2gh\biggl(\frac{M+m}{m}\biggr) \implies u=\sqrt{402}$$    To summarize myself, I am curious about the following: Why do the results differ? Shouldn't the energy be conserved as well as the momentum? Since it should be, then what is the flaw in my calculations? What to do when the correct answer to a question changes over time? My question concerns . I asked the question, and at the time selected the correct answer. However, time passes and libraries get updated, and now a different answer is actually correct.   I should probably select this new answer as the correct answer, but I feel bad for the person that will lose 15 reputation points even though is answer was the a good answer at that given point in time.  Any suggestions?