7.2.2 Greatest hits from previous weeks

7.2.2.1 How to make Jacobian automatically in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5790

If we have two vectors, $a$ and $b$, how can I make Jacobian matrix automatically in Mathematica? 
 
$$ a=\left( 
\begin{array}{c} 
x_1^3+2x_2^2 \\ 
3x_1^4+7x_2 
\end{array} 
\right);b=\left( 
\begin{array}{... 
[vector-calculus]
 

asked by George Mills https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1012 39 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 52 votes

7.2.2.2 Plotting Complex Quantity Functions

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3458

Trying to plot with complex quantities seems not to work properly in what I want to accomplish. I would like to know if there is a general rule/way of plotting when you have complex counterparts in ... 
[plotting] [complex] [faq]
 

asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 42 votes

answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 29 votes

7.2.2.3 QR Code in shopping cart handle

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26268

This week, the market people from my work wanted to put QR codes in shopping cart handles, but when they tested it, the QR code did not work. I noted that the cylindrical curvature (even small) ... 
[image-processing]
 

asked by Murta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2266 196 votes

answered by halirutan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=187 192 votes

7.2.2.4 How do I plot a plane EM wave?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1987

I would like to display an electromagnetic (EM) wave.  I have written code that works, but it does not "shade" the area between the graph and the axes.  Both the ... 
[graphics] [physics] [visualization]
 

asked by Rainforest Frog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=202 22 votes

answered by J. M.'s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 16 votes

7.2.2.5 Standard deck of 52 playing cards in curated data?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108

I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included? 
 
If not, is there a way ... 
[curated-data]
 

asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes

7.2.2.6 Why I get the "Set::write: "Tag Times in is Protected." error?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11868

Why I get the error below with this code: 
 
... 
[vector-calculus]
 

asked by Aurelius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1669 10 votes

answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 13 votes

7.2.2.7 Mathematica vs. Python - how does Mathematica compare to Python's scientific computing suite?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=86058

Python's family of packages for scientific computing has matured rapidly. I can pretty much replicate all of Mathematica's functionalities, but with production level and open-source code using the ... 
[python] [system-performance]
 

asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 49 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 36 votes