7.15.1 Top new questions this week

7.15.1.1 Command with arguments separated by comma II (typically an easy way to write matrices)

https://tex.stackexchange.com/landing/r/digest?cta=question&id=584918

Since I am using 2 x 2 matrices very frequently, I would like to define a command which would work like this: \matr{a, b, c, d} would produce 
$\begin{pmatrix} a & b \\ c & d \end{pmatrix}$. 
Of ... 
[macros] [comma-separated-list]
 

asked by Watson https://tex.stackexchange.com/landing/r/digest?cta=user&id=94816 10 votes

answered by wipet https://tex.stackexchange.com/landing/r/digest?cta=user&id=51799 8 votes

7.15.1.2 What's the difference between \ignorespaces and \ignorespacesafterend?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=585646

What's the difference between \ignorespaces and \ignorespacesafterend and should I ever use the former rather than the later? 
I've seen examples that place \ignorespacesafterend at the end of an ... 
[macros] [spacing]
 

asked by Peter Gerdes https://tex.stackexchange.com/landing/r/digest?cta=user&id=2743 9 votes

answered by campa https://tex.stackexchange.com/landing/r/digest?cta=user&id=82917 7 votes

7.15.1.3 Drawing an epicycloid in TikZ

https://tex.stackexchange.com/landing/r/digest?cta=question&id=584931

I am attempting to draw the plot of an epicycloid. The formula (which looks nicer compiled): 
x = (a+b)\cos{}\phi{}-b\cos{}\left(\frac{a+b}{b}\phi{}\right) 
y = (a+b)\sin{}\phi{}-b\sin{}\left(\frac{... 
[tikz-pgf]
 

asked by kpo7057 https://tex.stackexchange.com/landing/r/digest?cta=user&id=88034 8 votes

answered by gernot https://tex.stackexchange.com/landing/r/digest?cta=user&id=110998 11 votes

7.15.1.4 Is there any difference between `\let\A\B` and `\let\A=\B`?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=585613

I've seen some people writing things like 
\let\original@somemacro=\somemacro 
while I usually write 
\let\original@somemacro\somemacro 
Is there any difference between them? 
(I believe this question ... 
[macros]
 

asked by Jinwen https://tex.stackexchange.com/landing/r/digest?cta=user&id=194994 7 votes

answered by Steven B. Segletes https://tex.stackexchange.com/landing/r/digest?cta=user&id=25858 11 votes

7.15.1.5 How to get consistent arrow tips in TikZ and pgfplots?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=585226

I want to get consistent arrow tips for 
Arrows in TikZ drawings 
pgfplots axes 
Arrows used to annotate features in plots produced with pgfplots 
My solution works only for 1 and 3, as demonstrated by ... 
[tikz-pgf] [pgfplots] [tikz-arrows]
 

asked by user1362373 https://tex.stackexchange.com/landing/r/digest?cta=user&id=18181 6 votes

answered by hpekristiansen https://tex.stackexchange.com/landing/r/digest?cta=user&id=8650 3 votes

7.15.1.6 Why does LaTeX have \newtherorem rather than define environments for theorem, lemma, etc.?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=585115

It seems to me that the various theorem-like environments have styling (including numbering) that would most likely be determined on a publication style basis rather than varying from one author to ... 
[theorems]
 

asked by Don Hosek https://tex.stackexchange.com/landing/r/digest?cta=user&id=202780 6 votes

answered by David Carlisle https://tex.stackexchange.com/landing/r/digest?cta=user&id=1090 11 votes

7.15.1.7 Implement proof environment as normal paragraph, without list

https://tex.stackexchange.com/landing/r/digest?cta=question&id=585746

I am formatting a math book from another author that uses a lot of figures inside paragraphs, like those produced by wrapfigure environment. I am getting a lot of trouble because proof and other ... 
[amsmath] [lists] [wrapfigure]
 

asked by Miguel V. S. Frasson https://tex.stackexchange.com/landing/r/digest?cta=user&id=227903 5 votes

answered by barbara beeton https://tex.stackexchange.com/landing/r/digest?cta=user&id=579 6 votes