nested php ternary trouble: ternary output != if - else
Stacking Multiple Ternary Operators in PHP
How do I install the latest version of node.js? How do I install the latest  on Ubuntu? I've been looking around, and I can't find anything. Is there a Ubuntu package for node.js, or do I have to compile it myself? Systemd backed tmpfs | How to specify /tmp size manually I mount /tmp on tmpfs using:  sudo systemctl enable tmp.mount sudo systemctl start tmp.mount   But this way /tmp takes up all the free RAM:  $ df -h /tmp Filesystem      Size  Used Avail Use% Mounted on tmpfs           3.9G   12K  3.9G   1% /tmp $   How do I tell systemd tmp.mount to use only 1G? I know I can alternatively not use systemd and manually add an entry to /etc/fstab and specify the size there. But I don't want to do that. I want to use systemd backed tmpfs. How many solutions are there to $x_1 + x_2 + ... + x_5 = 21$? How many solutions are there to the equation      $x_1 + x_2 + x_3 + x_4 + x_5 = 21$    where $x_1, i = 1,2,3,4,5$ is a nonnegative integer such that $0 ≤ x_1 ≤ 3, 1 ≤ x_2 &lt; 4$, and $x_3 ≥ 15$?  I have correctly completed the previous parts of the question but am having trouble with this particular restriction.  The total number of solutions to the equation is $C(25,21) = 12650$.  I have tried to do each restriction individually:  For $0 ≤ x_1 ≤ 3$, I solved this by subtracting the number of solutions when $x_1 ≥ 4$ from the total number of solutions. This is $C(25,21) - C(21,17) = 5985$.  For $1 ≤ x_2 &lt; 4$, I have $C(24,20) - C(21,17) = 5985$.  For $x_3 ≥ 15$, I have $C(10,6) = 210$.  However, the restriction is when these are all together. I am not sure how to proceed. The answer is $106$. Variables are often adjusted (e.g. standardised) before making a model - when is this a good idea, and when is it a bad one? In what circumstances would you want to, or not want to scale or standardize a variable prior to model fitting?  And what are the advantages / disadvantages of scaling a variable? How to use Class in Java? There's a good discussion of Generics and what they really do behind the scenes over at , so we all know that Vector&lt;int[]&gt; is a vector of integer arrays, and HashTable&lt;String, Person&gt; is a table of whose keys are strings and values Persons.  However, what stumps me is the usage of Class&lt;&gt;.  The java class Class is supposed to also take a template name, (or so I'm being told by the yellow underline in eclipse).  I don't understand what I should put in there.  The whole point of the Class object is when you don't fully have the information about an object, for reflection and such.  Why does it make me specify which class the Class object will hold?  I clearly don't know, or I wouldn't be using the Class object, I would use the specific one. Should an image carousel on a mobile site automatically rotate? ARIMA equation interpretation I'm trying to replicate ARIMA (1,0,1)(1,0,1) equation in excel as a formula but I am not able to understand the interpretation of white noise residual e(t) or u(t).If could help me understand the interpretation and how to derive it from raw data it'll be really great.  Thanks Probability of complete coupon set in $K$ boxes where a box has $N$ distinct coupons? Say there is a contest to collect a full set of $M$ coupons.  Each box of product has $N$ distinct coupons of the $M$ possible coupons in it, selected uniformly without replacement from the $M$ possible coupons, the same $N$ in number for all boxes.  I'm interested in the probability that after opening $K$ boxes of product I have at least one complete set of the $M$ coupons.  My attempt has been to take the probability of a coupon not being in a box, use that to determine the probability of that coupon not being in any of the $K$ boxes, and then... I get flummoxed, and don't think this is the correct approach.  I searched the site for coupon collector problems, there are a couple that deal with similar situations (multiple in a box), but with the box having coupons selected with replacement, so duplication in a box is possible.  Right now I'm using a CAS to get probability of sums of hypergeometric samples having all bins covered to check my ideas, but that's utterly impractical for other than tiny cases.   Is this not as trivial as I think it is, or is there a direct way to calculate this? Let $A_n$ denote an $n \times n$ tridiagonal matrix.  $$A_n=\begin{pmatrix}2 &amp; -1 &amp; &amp; &amp; 0 \\ -1 &amp; 2 &amp; -1 &amp; &amp; \\ &amp; \ddots &amp; \ddots &amp; \ddots &amp; \\ &amp; &amp; -1 &amp; 2 &amp; -1 \\ 0 &amp; &amp; &amp; -1 &amp; 2 \end{pmatrix} \quad\text{for }n \ge 2$$  Set $D_n = \det(A_n)$  Prove that $D_n = 2D_{n-1} - D_{n-2}$ for $n \ge 4$. How to get Steam to recognize existing game files from a different source? Let's say I have a game bought on retail/other digital download and installed on my hard drive. I buy the same game (or a minor variant of it, say the GOTY edition) on Steam. It should be possible to use the existing installation to avoid the generally big downloads. This is very useful as it saves both bandwidth and time.   Previously, as far as I understood, Steam downloaded the game files directly to steam\steamapps\common\&lt;game_name&gt;. Since this folder would be created on starting the download, pausing and closing steam, copying the game files to this folder and then validating game files would make Steam absorb as much as possible and just download the missing files.  Currently, Steam downloads the files to steam\steamapps\downloading\&lt;game_id&gt; and then moves them over to the aforementioned folder once the download finishes. So first of all, what the final folder would be is not clear. So what would be the correct way of doing the same thing, that is, make steam use as much of the existing files as possible? Should the files be copied to downloading\*\, or should I figure out the actual folder (say via googling) and copy the files to steamapps\common\*\?  More specifically, I had a retail copy of Arkham City installed and I just bought the GOTY version on Steam. Now I tried both of the above things, in either case, the validating does not seem to do anything. Assuming I have the correct folder name steamapps\common\Batman Arkham City GOTY, according to , if I copy the files there, Steam seems to just continue with its 17GB download. If I copy it to steamapps\downloading\200260 then the download keeps stopping every few seconds with "Disk Write Error" after modifying 1 or 2 files, and I have to keep hitting resume. I'm looking for specific, real cases in which a causal relationship was inappropriately inferred from evidence of a correlation.   Specifically, I'm interested in examples that meet the following criteria:   Existence of the causal relationship was accepted as fact widely enough to have notable effects (on public policy, discourse, individual decisions, etc.). The link was inferred solely on the basis of correlative evidence (perhaps along with the existence of a coherent but unproven causal mechanism).  Causality has been objectively falsified or at least called into serious doubt.   The two examples that came to mind for me aren't quite ideal:   Sodium intake and blood pressure: As I understand it, it has since been determined that salt intake only increases blood pressure in sodium-sensitive individuals. The existence of a valid causal relationship (although not quite the one that was originally accepted) make this example less compelling. Vaccines and autism: I may have the background wrong, but I believe this link was surmised on the basis of both correlations and (fraudulent) experimental evidence. This example is weakened by the fact that (fake) direct evidence existed.   Note: I've seen this similar question:    My question differs primarily in that it focuses on notable, real-world examples and not on examples in which a causal link is clearly absent (e.g., weight and musical skill). If gravity is a pseudoforce in general relativity, then why is a graviton necessary? What is the cardinality of the set of the empty set? How to retrieve GET parameters from JavaScript Can I control voltage of USB data pins? "High response time" warnings in Google Webmaster Tools In my Google Webmaster Tools account, there are warnings about my site.     Some URLs listed in this sitemap have a high response time. This may indicate a problem with your server or with the content of the page.   What is the solution? How can orbitals be oriented if the nucleus is symmetrical? I know very little about quantum physics, but I just can't wrap my head around the fact that non-spherical orbitals appear to be "oriented", constituting a set of fixed "frame of reference axes".  Does it really work like that? Are there for a single atom given directions in which the orbitals "protrude"? And if so, what are they based on? If I understand it right, the nucleus is seemingly spherical - symmetrical with no unique axis of symmetry. What would then decide the orientation of the orbitals in space (with respect to the surroundings)?  Edit: I understand any orientation works to satisfy the wave equation. I was more curious why the atom would choose one direction, instead of any of the others. Is that fundamentally random? And is this setup retained further, or can it change at any time? Does “gay” still include the meaning “merry”? Dictionary.com lists , with “merry, lively” as the first entry.  Microsoft  for listing  (a real place) as his hometown:   Xbox Live considered the term gay absolutely inappropriate in any context.     As a non-native English speaker, my question is whether in contemporary English, does gay always mean homosexual? Are British and American English the same in this respect? I have a DEM layer from ASTER satellite and I want to get the slope information from it.  I use terrain analysis > slope, but the output is so wrong. Why is that?  Here is the DEM:     And here is the "Slope" that is totally wrong. It should stretch the values from 0 - 89.9097 but it does not. Clipping a figure to content