How to consume a JSON web service in Java
Parsing JSON from URL
Trouble with proving $A$ is an integrally closed domain $\Rightarrow$ $A[t]$ is integrally closed domain Is the term "errored out" a grammatically correct phrase, or just a colloquial one? Meaning of $\int \phi^\dagger \hat A \psi \:\mathrm dx$ While analysing a problem in quantum Mechanics, I realized that I don't fully understand the physical meanings of certain integrals. I have been interpreting:    $\int \phi^\dagger \hat A \psi \:\mathrm dx$  as "(square root of) probability that a particle with state $|\psi\rangle$ will collapse to a state $|\phi\rangle$ when one tries to observe the observable corresponding to $\hat A$" $\int \phi^\dagger  \psi \:\mathrm dx$ as "(square root of) probability that a particle with state $|\psi\rangle$ will collapse to a state $|\phi\rangle$".   All integrals are over all space here, and all $\phi$s and $\psi$s are normalized.  Now, I realize that  interpretation of the first integral doesn't really make sense when put side by side with the second one.   For example, when $|\phi\rangle$ is an eigenstate of $\hat A$, I get two different expressions for "the square root of probability that one will get the corresponding eigenvalue of $\psi$ when one tries to observe the observable corresponding to $\hat A$". As far as I can tell, $\int \phi^\dagger \hat A \psi \:\mathrm dx \neq\int \phi^\dagger  \psi \:\mathrm dx $, even if $|\phi\rangle$ is an eigenstate of $\hat A$. I am inclined to believe that the second integral is the correct answer here (it comes naturally when you split $|\psi\rangle$ into a linear combination of basis vectors). But I am at a loss as to the interpretation of the first integral.  So, my question is, what are the physical interpretations of $\int \phi^\dagger \hat A \psi \:\mathrm dx$ and $\int \phi^\dagger  \psi \:\mathrm dx$?  (While I am familiar with the bra-ket notation, I have not used it in this question as I don't want to confuse myself further. Feel free to use it in your answer, though) Tool to confirm Gaussian fit I have a series of (x1,y1) points.  I'm using a 3rd party software tool to which I feed these points. The tool then provides a mechanism for me to get back a series of (x2,y2) points that are on a Gaussian curve that has been fit to the data.  I'd like to confirm that the points I'm getting back are correct (because, frankly, sometimes they don't look like they are.)  What would be an easy on-line or Excel procedure that would allow me to enter the X1, Y1 series and then get back a series of X2, Y2 points, plot both series, and maybe even see the s.d.?  It's been 20+ years since I did any stats, so I'm just "cook-booking" this with no understanding of what I'm trying to do.  EDIT  The is a plot by wavelength, of intensity.  X-axis is the colors of a rainbow, in the familiar ROYGBIV order. The Y-axis is measured intensity of that particular color.   The help page from the vendor is here:    I call the library with each x1, y1 data point.  I then call the method above. I then call the library again with a series of x values (or maybe the x1 series itself), retrieving the y2 values on the fitted curve. I also retrieve the sd of the fit.  EDIT 2  Below is a link to an image of the dataset and Gaussian fit that has me concerned.  I think that the peak of the fitted curve is too low. Huge confusion with Fermions and Bosons and how they relate to total spin of atom I am supremely confused when something has spin or when it does not. For example, atomic Hydrogen has 4 fermions, three quarks to make a proton, and 1 electron. There is an even number of fermions, and each fermion has a 1/2 spin. Since there are an even number of fermions, the total spin value is an integer. This spin number is the "intrinsic" spin number that cannot be changed, but its orientation "up" or "down" can be changed.  For atomic Hydrogen, it is a Boson because it has integer spin, however it also has a single electron. I read on physics forums, , that the spin of atom comes from the electrons and not its nucleus. I also read on here, , that the spin of atomic Hydrogen is 1/2! The answer says atomic Hydrogen has spin 1/2 because it ignores the nuclear spin.  This is one thing that is confusing me. Shouldn't atomic Hydrogen have an integer spin because of the nuclear component? So does atomic Hydrogen have spin and is affected by a magnetic field? Nuclear spins are affected by magnetic fields, but they aren't as affected as electrons according to the discussion on physics forums.  Why do we ignore nuclear spin sometimes? Also, can someone help me out here with all the possibilities?  Is there a Boson with an half integer spin value? (Surely, there must not be) However atomic Hydrogen is one of those cases! (It seems...) (Why don't we cancel out the nuclear spin with the electron spin?)  Say we have another atom that is a Boson, It has unpaired electrons in different orbitals, so what determines whether or not electrons fill in orbitals as spin up or down? Does spin down nuclear spin cancel out a electron up spin? Seems that I just proved $2=4$. How to insert a very large number of records into a MySql database as fast as possible We are sponsoring a family to visit us in UK as friends from Madagascar for two weeks. They have a 6 year old and a 16 month old.   Do the kids need their own visas, and are they the standard visitor visa or a special child visa?   Also, when I try and apply on the website I can only apply for one person so how do I apply for all the individuals in the family?   I have looked on the Immigration website and can't find the answers I need. If $\sum_na_n=\infty$ and $a_n\downarrow 0$ then $\sum\limits_n\min(a_{n},\frac{1}{n})=\infty$ If $\sum_na_n=\infty$ and $a_n\downarrow 0$ then $\sum\limits_n\min(a_{n},\frac{1}{n})=\infty$     My  idea:  $$b_{n}=\min(a_{n},\tfrac{1}{n})\Longrightarrow b_{n}\le a_{n},b_{n}\le\tfrac{1}{n}$$ then I don't know how to go on. In the C and C++ programming languages, what is the difference between using angle brackets and using quotes in an include statement, as follows?   #include &lt;filename&gt;  #include "filename" I am currently working on an update of tkz-euclide and new documentation but I just met the following problem. If I compile this code with pdflatex or lualatex and pgf 2.1 (The library babel does not exist with pgf 2.1) then the code compiles fine but with 3.0 pgf I must comment on the call \usetikzlibrary{babel} (pgf doc gives so I recommend to always load this library by saying \usetikzlibrary{babel}).  I'd like to know where the error occurred. Especially I would like to work around this problem.   With \usetikzlibrary{babel} I get the error Latex Error: ./untitled 2.tex:46 Undefined control sequence. l.1 \tkz@line@start  Bug in babel, bug in tikzlibrary{babel} bug in my code. I would like to keep  \usetikzlibrary{babel} but to avoid the error.  %!TEX TS-program = pdflatex \documentclass[a4paper]{article} \usepackage[french]{babel} \usepackage{tikz}  \usetikzlibrary{calc} %\usetikzlibrary{babel}  \makeatletter \pgfkeys{%     tkzdrawline/.cd,     start/.code         =  {\gdef\tkz@line@start{#1}},%     end/.code           =  {\gdef\tkz@line@end{#1}},%     start style/.code   =  {\tikzset{tkzstartstyle/.style={#1}}},%     end style/.code     =  {\tikzset{tkzendstyle/.style={#1}}},%    /tkzdrawline/.unknown/.code ={\let\searchname=\pgfkeyscurrentname\pgfkeysalso{%                          \searchname/.try=#1,/tikz/\searchname/.retry=#1}}}  %&lt;--------------------------------------------------------------–&gt; %                              Draw line %&lt;--------------------------------------------------------------–&gt; \pgfkeys{tkzdrawline/.cd, start/.code       =  {\def\tkz@line@start{#1}},% end/.code         =  {\def\tkz@line@end{#1}}, start style/.code =  {\tikzset{tkzstartstyle/.style={#1}}}, end style/.code   =  {\tikzset{tkzendstyle/.style={#1}}},   /tkzdrawline/.unknown/.code   = {\let\searchname=\pgfkeyscurrentname                                  \pgfkeysalso{\searchname/.try=#1,                                 /tikz/\searchname/.retry=#1}}}%         %&lt;--------------------------------------------------------------–&gt;  \def\tkzDrawLine{\pgfutil@ifnextchar[{\tkz@DrawLine}{%                                   \tkz@DrawLine[]}}%   \def\tkz@DrawLine[#1](#2,#3){%  \begingroup   \pgfkeys{tkzdrawline/.cd,start = {}, end = {}, start style={}, end style={},}   \pgfqkeys{/tkzdrawline}{#1}   \draw[ /tkzdrawline/.cd,#1] (#2) to%     node [at start,left,/tkzdrawline/.cd,tkzstartstyle] {\tkz@line@start}%     node [at end,right,/tkzdrawline/.cd,tkzendstyle] {\tkz@line@end} (#3);  \endgroup  }%   \makeatother   \begin{document}    \begin{tikzpicture}      \node (A) at (0,1) {};       \node (B) at (5,2) {};       \tkzDrawLine[end = {$\alpha$}](A,B)       \end{tikzpicture}  \end{document} Why can my keyboard only digest 6 keypresses at a time? When I slam my hand onto my keyboard, only a maximum of 6 keys will be registered, I've tested this for the past few minutes and was unable to get more than 6. Is this the same on all keyboards? If not, what would be the distinguishing factor, If yes: why 6 specifically?  For clarification: I do not have a usecase for this, I am simply curious Derive a formula to find the number of trailing zeroes in $n!$ I left them (at) home Consider this question:  Where are they (things or people)?  Would the following answer be with (at), without it or either one?  I left them (at) home  I have done a quick Google search and found quotes for both cases, with and without:  This Widow's 4 Kids Were Taken After She Left Them Home Alone. Leaving Your Child Home Alone - KidsHealth Gerry said, &quot;I left them at home.&quot; Gerry sat down and turned on the TV set just as Mark would have done.  I read about &quot;home&quot; being an adverb but also know &quot;stay at home moms&quot; for example. So you see I need definite answers. How do I export the code documentation in C# / VisualStudio 2008? I have always made a point of writing nice code comments for classes and methods with the C# xml syntax. I always expected to easily be able to export them later on.  Today I actually have to do so, but am having trouble finding out how. Is there something I'm missing? I want to go Menu->Build->Build Code Documentation, but there is no option to do that, there. Does the closedness of a subgroup $H$ of $G$ imply that for $h\in H, g\in G \setminus H: hg \not \in H$?  I'm new to abstract algebra and this would appear to be a useful result. However, by definition, a subgroup is nearly closed, and I don't think this directly implies that for any element $g$ from $G$ not in $H$, the composition $gh \not \in H$.  Is this in fact a true statement? I am looking for a way to clean up the mess when my top-level script exits.  Especially if I want to use set -e, I wish the background process would die when the script exits. What does the Asterisk * mean in Objective-C? Can the coefficient of static friction be less than that of kinetic friction? When a user who approved an edit is removed, an incorrect "-2 reverted" event appears in reputation history I am aware that . But now there is an extraneous "reverted" event to go along with user removal:     Source: .   The edit was not reverted, it's . In any case, I should not lose 2 points twice for the total of -4. And indeed, my reputation only dropped from 131 to 129 despite what the history suggests.   So the line with "-2 reverted" is a bug.     A more extreme example:  got 21 "reverted" events on 2017-06-30, none of which should be there. His rep loss is 42, not 84 as the reputation history says.