I am colorblind. I am looking for an app to help me identify colors by their basic names (blue, green, ...) when I am working on powerpoint or excel on mac (OSX 10.12).  On windows, I was using  quite successfully. This app translates the RGB code of the pixel under your mouse into intelligible color names such as blue, green, ... it's a real time-saver when you have to create powerpoints or excel.  I could not find anything similar so far on mac. I tried apps such as Visolve or Sim Daltonism but they did not have this simple functionality.  Please note I am not looking for a color picker such as DigitalColor Meter, that would just read out color RGB codes from pixels. I need a tool that "names" colors, stay on top of screen, with a compact window, just like whatcolor.
I used to find color codes which I want to use for texts or background colors on htmls with color edit tool of MS paint which pre-installed on Windows. But now I use Mac instead of Windows. How can I find color codes with Mac? Is an software like MS paint pre-installed on Mac?
Background: I'm giving a presentation to colleagues at work on hypothesis testing, and understand most of it fine but there's one aspect that I'm tying myself up in knots trying to understand as well as explain it to others.  This is what I think I know (please correct if wrong!)   Statistics that would be normal if variance was known, follow a $t$-distribution if the variance is unknown CLT (Central Limit Theorem): The sampling distribution of the sample mean is approximately normal for sufficiently large $n$ (could be $30$, could be up to $300$ for highly skewed distributions) The $t$-distribution can be considered Normal for degrees of freedom $&gt; 30$   You use the $z$-test if:   Population normal and variance known (for any sample size) Population normal, variance unknown and $n&gt;30$ (due to CLT) Population binomial, $np&gt;10$, $nq&gt;10$   You use the $t$-test if:   Population normal, variance unknown and $n&lt;30$ No knowledge about population or variance and $n&lt;30$, but sample data looks normal / passes tests etc so population can be assumed normal   So I'm left with:    For samples $&gt;30$ and $&lt;\approx 300$(?), no knowledge about population and variance known / unknown.   So my questions are:   At what sample size can you assume (where no knowledge about population distribution or variance) that the sampling distribution of the mean is normal (i.e. CLT has kicked in) when the sampling distribution looks non-normal? I know that some distributions need $n&gt;300$, but some resources seem to say use the $z$-test whenever $n&gt;30$... For the cases I'm unsure about, I presume I look at the data for normality. Now, if the sample data does looks normal do I use the $z$-test (since assume population normal, and since $n&gt;30$)? What about where the sample data for cases I'm uncertain about don't look normal? Are there any circumstances where you'd still use a $t$-test or $z$-test or do you always look to transform / use non-parametric tests? I know that, due to CLT, at some value of $n$ the sampling distribution of the mean will approximate to normal but the sample data won't tell me what that value of $n$ is; the sample data could be non-normal whilst the sample mean follows a normal / $t$.  Are there cases where you'd be transforming / using a non-parametric test when in fact the sampling distribution of the mean was normal / $t$ but you couldn't tell? If a Matrix Has Only Zero as an Eigen-Value Then It Is Nilpotent Given six numbers $x,y,z,a,b,c$ which satisfy the following relations. Express $x+y+z$ in terms of $a,b,c$ Given six numbers $x,y,z,a,b,c$ which satisfy the following relations $y^2+yz+z^2=a^2$ $z^2+zx+x^2=b^2$ $x^2+xy+y^2=c^2$ Express $x+y+z$ in terms of $a,b,c$    My attempt: $\dfrac{(y^3-z^3)}{(y-z)}=a^2,\dfrac{(z^3-x^3)}{(z-x)}=b^2,\dfrac{(x^3-y^3)}{(x-y)}=c^2$ But this step didn't seem to help. So I tried adding and expressing $k(a+b+c)^2$ but some other unmanagable elements came along. I could not think of any other way to approach the problem. Please help. Subequation: Counter too large Is there a non written rule to which person to use in the PhD thesis, 5 years of using "We" in the papers have brought me to the innate necessity to do it every time I describe something.  Recently, though, one of my lab-mates told me that I should use I, since it is your work, if the thesis were co-written, then it would be a different story.  Is there any standard in your universities, or do you have any preferred practice. Do I need a transit visa for a layover via airports in the UAE, such as Dubai International Airport or Abu Dhabi International Airport? If so, what are the requirements for such a visa? Can I get the transit visa on arrival? Is there a rule in British English about how to pronounce "either"? There are two common pronunciations of "either": British /ˈaɪðər/ and American /ˈiːðər/. If Americans are more or less consistent in this regard, then the Brits seem to be freely using both. In fact, from what I can tell, "either this or that" is more often in the first form, whereas "me either" is in the second. But I may be wrong. Is there any kind of an informal rule in the modern British English with regard to this? USB WiFi dongle device that can emulate a virtual mass storage device for a home video player Is there a USB WiFi dongle device that can:   Emulate a virtual mass storage device for a home video player But in fact shows the files from a network-shared folder? If one were to take a similar path as  in shooting candid street photography today, should they be concerned about laws or other realistic norms of today? I am wondering specifically in the US speaking broadly of all states. I am not looking for legal advice, but anything that one photographer to another would caution against as potentially being grey or obviously illegal.  Similar previous question: I've doing some researches since few days and I haven't really got an answer to my question.  I am in the process of building a huge file server for the company I work for. We bought a server case  with 24 bays and drives. Now I am stuck at the point where I have to choose the RAID card. I saw a RAID card from LSI that offer 6 internals mini-SAS 8087 ports (6x4) and would work perfectly with my build. However, it's not cheap.  I have been reading about the subject and I found something called SAS Expander. They are cheap.  with 6 mini SAS 8087 for 225$ (instead of 1150$ of the other one).  Now my question, how would I link an SAS Expander with a RAID card ? Do I need to a buy a RAID card with only 1 external 8088 port and link it with the other card ? Could someone clarify this for me because I haven't found any good documentation on it.  Thanks you. Can \includegraphics be used to change an image color? I'm including a number of PDF images in my document using \includegraphics.  I'm wondering if there's a way for LaTeX to adjust their color profile, hopefully the same way it can flip images upside down, resize, and crop, as here:   Let me detail a little more my desired outcome, in case there's another way to achieve this: The images are brightly colored---I'd like to reduce color levels, or possibly render them grayscale, and I'd prefer to not have to do external pre-processing, if this is possible.  I'm using XeTeX. Make window always on top? Scheduling a Round Robin tournament - 4-way games I'm looking to schedule 16 players to play a round robin tournament with each other such that there are 4 players at each table.  I'd like for each player to play with each other player exactly once over the course of 5 rounds.  I just took a look at this post:  , and I was wondering if anyone knows if the case n=m=4 has been solved, and if so what that solution is. Vertical Text in Wpf TextBlock Is it possible to display the text in a TextBlock vertically so that all letters are stacked upon each other (not rotated with LayoutTransform)? ContourPlot of implicit function doesn't work when I square the equation plist or sqlite I have seen a "Universal Laptop Adapter" sold in a computer shop before. I am thinking of getting one for a laptop. Is it safe to use? What differences are there between one of these and a typical laptop adapter? How can I execute an equivalent of `head -z` when I don't have the `-z` option available? I found the following proof arguing for the irrationality of $\sqrt{2}$.     Suppose for the sake of contradiction that $\sqrt{2}$ is rational, and choose the least integer $q &gt; 0$ such that $(\sqrt{2} - 1)q$ is a nonnegative integer. Let $q'::= (\sqrt{2} - 1)q$. Clearly $0 &lt; q' &lt; q$. But an easy computation shows that $(\sqrt{2} - 1)q'$ is a nonnegative integer, contradicting the minimality of $q$.   Clearly, this is a vague proof in that it expects the reader to work out the math involved on his own. I took that as an exercise and worked out the following:  Assuming $\sqrt{2}$ to be rational, let $$\sqrt{2} = \frac{p}{q}$$ where $p$ and $q$ are least possible integers.  Clearly then, $\sqrt{2} - 1$ would also be rational, $$\sqrt{2} - 1 = \frac{p-q}{q}$$ where both $(p-q)$ and $q$ are also integers.  Multiplying both sides by $q$, we get $$(\sqrt{2} - 1)q = (p-q) = q'$$ where $q'$ is an integer. Using, $2&gt;\sqrt{2} &gt; 1$ , we get $$1&gt;\sqrt{2}-1&gt;0$$ proving that $q'$ is a non-negative integer.  As stated in the proof, computing $(\sqrt{2}-1)q'$ we get, $$(\sqrt{2}-1)q' = \frac{(p-q)^2}{q}$$which is not necessarily an integer (in fact necessarily not an integer). However, the proof claims it to be.  Am I missing something or something is wrong with how I proceeded?  Here is a link to the textbook where I found this proof: , (p 32, problem 1.14).  P.S. This is my first post here and my first time with TeX. I'd also like to know if there is anything wrong with the way my question is presented. Windows Unable to Delete ._. File I currently have a file on the root of my external hard drive simply named ._., which I am guessing was added to my hard drive after using it on my MacBook a while ago.  I'm trying to delete this file on my Windows 10 machine; however Windows keeps claiming the file cannot be found.    I also tried deleting the file through an elevated command prompt; however the same message is returned.    Is there any way I can delete this file from my hard drive through Windows?