5.27.1 Top new questions this week

5.27.1.1 Make lens aperture in Tikz

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=502872

I want to make a lens aperture with different f numbers(sizes of the holes). I started with this code but it wont make it look like a complete aperture. Appreciate any help. 
... 
[tikz-pgf]
 

asked by RD1153 https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=80982 14 votes

answered by David Purton https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=87678 26 votes

5.27.1.2 Different answers of calculations in LuaLaTeX on local computer, lua compiler and on overleaf

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=502742

Here is the code. It makes use of the file matrix.lua available at the following link. 
https://github.com/davidm/lua-matrix/blob/master/lua/matrix.lua 
The following code is to be run by matrix.lua  ... 
[luatex] [overleaf] [lua] [luacode] [directlua]
 

asked by user61681 https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=75476 14 votes

answered by Henri Menke https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=10995 19 votes

5.27.1.3 Feedback diagram

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=502559

I want to create a feedback diagram similar to 
I managed to get the following: 
\documentclass{article} 
\usepackage[latin1]{inputenc} 
\usepackage{tikz} 
\usetikzlibrary{shapes,arrows} 
... 
[tikz-pgf] [diagrams]
 

asked by jtsbattle https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=179783 13 votes

answered by Black Mild https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=140722 14 votes

5.27.1.4 How to draw a flow chart?

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=503128

Could you give me a hint on this one? Ia^\200\231m new to TeX 
Text from the screenshot 
Users 
A~\215tems 
Training Set 
Validation Set 
Train 
Test 
0 
Mask test ratings 
... 
[tikz-pgf] [pstricks]
 

asked by jassonpottersen https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=192311 11 votes

answered by user121799 https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=121799 12 votes

5.27.1.5 Trying to draw a hierarchy

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=503154

Could you help me with these two draws? 
First: 
Second: 
mwe (taken from Here) 
\documentclass[tikz,border=7pt]{standalone} 
\usetikzlibrary{positioning,arrows.meta} 
\begin{document} 
... 
[tikz-pgf]
 

asked by Delan https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=189304 8 votes

answered by Zarko https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=18189 7 votes

5.27.1.6 Plotting Autoregressive Functions / Linear Difference Equations

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=502920

Assume there to be some function $k_{t+1} = f(k_t)$. Is there any smarter way to plot a path starting from $k_0$, doing $n$ steps? Thanks in advance. 
\documentclass[ 
paper=A4, 
... 
[tikz-pgf] [pgfplots] [loops]
 

asked by Hiwi Makro https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=173523 8 votes

answered by user121799 https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=121799 10 votes

5.27.1.7 Adding space between matrices

https://tex.stackexchange.com/landing/r/newsletter?cta=question&id=503325

I am having some trouble when changing the order of the matrices. The dot product does not look very well, actually it is like it is embedded; hard to spot. How can add space between the two matrices  ... 
[matrices]
 

asked by NaveganTeX https://tex.stackexchange.com/landing/r/newsletter?cta=user&id=185467 7 votes