Now before you all call me a retard Let me just state that I know nothing about the electrical world at all.  But I need someone help me answer my question   So I have a TV that says on the back 'Input; DC 12v 3000aH' and I have a power supply that says 'Output; DC 12v 2A'  Will that work? Or burn down my house? (I assume 'aH' and 'A' means the same thing) My common sense tells me that the power supply should say 'Output; DC 12v 3A' (Fyi i lost the original power supply for the TV)  So I need to buy a new one  Much appreciate anyone who answers this
Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.
"Baggage" versus "luggage" multiple regression and multiple comparisons Say I fit a multiple regression of p explanatory variables. The t-test will allow me to check if any single one of those is significant ($H_0: \beta_i = 0$). I can do a partial F-test to check if some subset of them is significant ($H_0: \beta_i=\beta_j=...=\beta_k=0$).  What I often see though is that someone gets 5 p-values from 5 t-tests (assuming they had 5 covariates) and only keeps the ones with a p-value &lt; 0.05. That seems a bit incorrect as there really should be a multiple comparison check no? Is it really fair to say something like $\beta_1$ and $\beta_2$ are significant but $\beta_3$, $\beta_4$ and $\beta_5$ are not?   On a related note, say I run 2 regressions on 2 separate models (different outcome). Does there need to be a multiple comparison check for significant parameters between the two outcomes?  Edit: To differentiate from the similar question, is there any other interpretation to the p-values besides: "B_i is (in)significant, when adjusting for all the other covariates"? It doesn't seem that this interpretation allows me to look at every B_i and drop those less than 0.5 (which is similar to the other post).   It seems to me that a sure fire way to test whether B_i and Y have an a relationship would be to get a correlation coefficient p-value  for each covariate and then do a multcomp (although that would definitely lose signal).  Finally, say I computed the correlation between B1/Y1, B2/Y1 and B3/Y1  (thus three p-values). Unrelatedly, I also did a correlation between T1/Y2, T2/Y2, T3/Y2. I'm assuming the correct Bonferroni adjustment would be 6 for all 6 tests together (rather than 3 for the first group and 3 for the second group - and thus getting 2 "semi"-adjusted p-values). In response to  question, I started to think about what it means when a Wild Magic Surge results in a "You cast spell-X".  So, "specific beats general" gives:   You can cast a second spell when you would not normally be allowed to You can cast a spell you don't know If the surge forces you to cast a concentration spell you would lose any concentration spell that you currently had active Subject to what the specific entry says you can target it how you like Unless the specific entry prohibits it you could use metamagic on the spell   I am pretty confident in all of the above but if anyone disagrees please address in an answer.  Here comes the question.  How does this impact on your available spell slots?  "You cast ..." to me suggests that if you have an applicable slot available then you have to use it to cast the spell because that is the general rule for casting spells but if you don't then "specific beats general" and it is cast anyway.  Specific examples:     You cast fireball as a 3rd-level spell centered on   yourself   This must be a 3rd level spell:   if you have a 3rd level slot available you have to use it? if you don't, if you have 5 sorcery points and a bonus action available must you use these to get that slot? if you don't have any of that then the spell goes off anyway?      You cast confusion centered on yourself.   No level specified and confusion is a 4th level spell:   if you have a 4th level slot available you have to use it? if you have a 4th, a 6th and an 8th level slot you can choose which one to use? if you have only a 5th level slot but also 6 sorcery points and a bonus action, you could choose to use the 5th level slot or use the points to create a 4th level slot? if you don't have any 4th level or higher slots but you have 6 sorcery points and a bonus action available must you use these to get that slot? if you don't have any of that then the spell goes off anyway?   And so on ... If $\mid a_{jj}\mid \gt \sum_{i \neq j} \mid a_{ij} \mid$ then vectors $a_1,\dots ,a_n \in \mathbb{R}^n$ are linearly indendent. Let $a_1,\dots ,a_n \in \mathbb{R}^n$ with $a_i = (a_{i1}, \dots , a_{in})$.  Show that when $\mid a_{jj}\mid \gt \sum_{i \neq j} \mid a_{ij} \mid \; \forall \; j\in \{1,\dots ,n\}$, then $a_1,\dots ,a_n$ are linearly independent.  I want to show that the matrix \begin{matrix} a_{11} &amp; a_{21} &amp; \cdots &amp; a_{n1} \\ a_{12} &amp; a_{22} &amp; \cdots &amp; a_{n2} \\ \vdots &amp; &amp; \ddots &amp; \\ a_{1n} &amp; a_{2n} &amp; \cdots &amp; a_{nn} \end{matrix} can be transformed into an upper triangular matrix with all entries in the main diagonal $\neq 0$.  For the cases $n=1$ and $n=2$ this is easy. However, I fail to show this for the general case; the problem being that the tranformations mess up the coefficients such that I can't use the assumption on the $a_{jj}$'s anymore.  I'm pretty sure that this has already been solved somewhere on here, but I don't know how to search for it. Is it possible to flash a custom ROM without a custom recovery image For an un-rooted device, almost all articles/forum posts I've read say that in order to flash a custom ROM you first need to flash (or boot) a custom recovery image like TWRP.   I'm not sure I understand why. If the bootloader is unlocked shouldn't it be possible to manually flash images that make up the custom ROM to the required partitions with fastboot flash &lt;partition&gt; [ &lt;xxxx.img&gt; ], and leave the stock recovery untouched.  I realize that this may be difficult and that there is no benefit in doing it this way, but I'm curious to know whether or not it is possible, and if not, why? Upgrade or replace a Wubi installation? I've got Windows 7 with Wubi 11.10 installed. I would like to upgrade to 12.04 but I'm not sure what the best path would be.  I'm not skilled enough to use Ubuntu all the time, and my iPhone requires me to run some Windows version for the damn iTunes software. I would love to run Windows XP but I can't figure out how to install it via USB -- my computer has no cd drive.  I'd like to run Windows XP and Wubi 12.04 on top of that. Or, perhaps, Ubuntu 12.04 natively and Windows XP alongside of that. So I guess I have 2 questions:   (lazy) Should I upgrade my Wubi from inside Ubuntu, or should I remove Wubi 11.10 from within Windows and install a brand new Wubi 12.04? (proper) How can I install Windows XP and Ubuntu 12.04 alongside each other?   Update: I am going to create a separate question post about the above #2 question... I realize it's wrong to ask two questions in one post when they are that different. Find all integral solutions of $y^2=x^3+7$ Find all integral solutions of $y^2 = x^3+7$.  I tried to use many different moduli, but it never works. With modulo $9$, you can get $x$ is divisible by $3$. Batch processing LiDAR files (.las to raster) with PyQGIS? for layers in glob.glob("*.las"):         processing.runalg("grass7:r.in.lidar", "input_las",5,1,"",1,100,"","",5,"","",False,True,True,"331289.57265,337990.42735,4558790.0,4560890.0",0,layers+"E:/las_new/.tif")      {'output': 'PNOA_2016_CAT_huso31_346-4560.lasE:/las_new/.tif'}   {'output': 'PNOA_2016_CAT_huso31_346-4562.lasE:/las_new/.tif'}   {'output': 'PNOA_2016_CAT_huso31_346-4564.lasE:/las_new/.tif'}   {'output': 'PNOA_2016_CAT_huso31_346-4566.lasE:/las_new/.tif'}   {'output': 'PNOA_2016_CAT_huso31_346-4568.lasE:/las_new/.tif'}   {'output': 'PNOA_2016_CAT_huso31_346-4570.lasE:/las_new/.tif'}   output_ras=("E:/las_Ras")   for layers in glob.glob("*.las"):     processing.runalg("grass7:r.in.lidar", "input_las",5,1,"",1,100,"","",5,"","",False,True,True,"331289.57265,337990.42735,4558790.0,4560890.0",0,layers+"output_ras.tif")      {'output': 'PNOA_2016_CAT_huso31_346-4560.lasoutput_ras.tif'}   {'output': 'PNOA_2016_CAT_huso31_346-4562.lasoutput_ras.tif'}   {'output': 'PNOA_2016_CAT_huso31_346-4564.lasoutput_ras.tif'}   {'output': 'PNOA_2016_CAT_huso31_346-4566.lasoutput_ras.tif'}   {'output': 'PNOA_2016_CAT_huso31_346-4568.lasoutput_ras.tif'}   {'output': 'PNOA_2016_CAT_huso31_346-4570.lasoutput_ras.tif'}     for layers in glob.glob("*.las"):     processing.runalg("grass7:r.in.lidar", "input_las",5,1,"",1,100,"","",5,"","",False,True,True,"331289.57265,337990.42735,4558790.0,4560890.0",0,"output_ras.tif")      {'output': 'output_ras.tif'}   {'output': 'output_ras.tif'}   {'output': 'output_ras.tif'}   {'output': 'output_ras.tif'}   {'output': 'output_ras.tif'}   {'output': 'output_ras.tif'}   I would like to batch process many LAS files to rasters using the PyQGIS algorithm. As you can see in the code, I think the final problem is with the output. It does not write the files out to my defined output pathway as tif files. Also how can I make sure the naming of output rasters are according to the original LAS they are generated from? What am I doing wrong here? Not a pro at Python. Started 3 days ago. Find all number $n\in \mathbb N$ such that $\varphi (n)=14$ How can I redirect the user from one page to another using jQuery or pure JavaScript? Graduate school admission with a degree in a different field Can I be admitted to graduate school in a different field from my degree?  Specific cases include:   If I've taken plenty of advanced courses in field X in the process of completing a degree in another field, can I apply to graduate school in X? What if I haven't taken many courses in X, but I have acquired a good grasp of X through self-study or working in a related field? What if I've never studied X, but I have done very well in an unrelated field?  Could I be admitted to graduate school in X on the basis of general intellectual promise, and then make up the missing background after enrollment?   Note that this question is an attempt to provide a comprehensive answer, to avoid the need for a profusion of field-specific questions on this topic (see the associated ). Please feel free to edit the question or answer to improve them. ArrayList vs List I saw this reply from Jon on :     If you want a single collection to   contain multiple unrelated types of   values, however, you will have to use   List&lt;object&gt;   I'm not comparing ArrayList vs List&lt;&gt;, but ArrayList vs List&lt;object&gt;, as both will be exposing elements of type object. What would be the benefit of using either one in this case?  EDIT: It's no concern for type safety here, since both class is exposing object as its item. One still needs to cast from object to the desired type. I'm more interested in anything other than type safety.  EDIT: Thanks Marc Gravell and Sean for the answer. Sorry, I can only pick 1 as answer, so I'll up vote both. Here's an example:  Double d = (1/3); System.out.println(d);   This returns 0, not 0.33333... as it should.  Does anyone know? How to find the foreach index? The comments in  say that I shouldn't wait until low battery charge level before I charge, because that reduces battery life (this is contrary to my understanding before that the faster we charge (without waiting for battery to discharge) the worse it will be for battery life). My question is, when I should generally start charging to avoid this effect? 20%?   Interesting question: If we always limit the usage of the battery only 20% and above, won't we, in effect, reduces our battery capacity to 80%, because we will only use the battery in 20%-100% state? Most efficient way to test equality of lambda expressions This question has come up    ( ), but I'm finding the answers to be generally incomplete. The general question is "Why does/doesn't my job get killed when I exit/kill ssh?", and here's what I've found.  The first question is:  How general is the following information?  The following seems to be true for modern Debian linux, but I am missing some bits; and what do others need to know?   All child processes, backgrounded or not of a shell opened over an ssh connection are killed with SIGHUP when the ssh connection is closed only if the huponexit option is set: run shopt huponexit to see if this is true. If huponexit is true, then you can use nohup or disown to dissociate the process from the shell so it does not get killed when you exit.  Or, run things with screen. If huponexit is false, which is the default on at least some linuxes these days, then backgrounded jobs will not be killed on normal logout. But even if huponexit is false, then if the ssh connection gets killed, or drops (different than normal logout), then backgrounded processes will still get killed.  This can be avoided by disown or nohup as in (2). There is some distinction between (a) processes whose parent process is the terminal and (b) processes that have stdin, stdout, or stderr .  I don't know what happens to processes that are (a) and not (b), or vice versa.   Final question: How can I avoid behavior (3)?  In other words, by default in Debian backgrounded processes run along merrily by themselves after logout but not after the ssh connection is killed.  I'd like the same thing to happen to processes regardless of whether the connection was closed normally or killed.  Or, is this a bad idea?  Edit: Another, important way to keep jobs of being killed, that works (?) in either case is to run them through .  But, the question is more about understanding when things get killed and when they don't: sometimes people want the jobs to be killed on logout, for instance.  More threads: -  -  -  -  -  -  -  - Determining "level" of an NPC ally for purpose of budgeting encounter XP The roots of the equation $z^n=(1+z)^n$... The complex roots of the equation      $$z^{n}=(1+z)^{n}$$   $A.$ are vertices of a regular polygon  $B.$ lie on a circle  $C.$ are collinear  $D.$ none of these  Don't know where to start.. Please help.!  NOTE:  $z$ is a complex number. Cite_key instead of a number, what is going on? I have the following problem: I correctly obtain a numbered bibliography at the end but along the text the cite_key appear instead of a number. How to fix this problem?   \documentclass[11pt]{book}  \usepackage[]{biblatex} \begin{document} %some text  ... \cite{ABKM2015}... %some text  \begin{thebibliography}{99} \bibitem{ABKM2015} Arroja, F. and Bartolo, N. and Karmakar P. and Matarrese, S. (2015). \newblock The Two Faces of Mimetic Horndeski Gravity             \newblock {\em ArXiV}, 1506.08575 (2015). \end{thebibliography} \end{document}   After compiling I get ... [ABKM2015] ... while I want for example  [1].