8.40.2 Greatest hits from previous weeks

8.40.2.1 How to build a bvh (a motion capture file format) player in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=60292

How to build a bvh player that can be used to visualize human motions in Mathematica? Any 
idea or sample code would be appreciated. 
... 
[graphics3d] [import] [animation] [visualization] [code-request]
 

asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 Score of 49

answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 Score of 97

8.40.2.2 Plot data from txt file?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5910

I have data in file.txt which can be expressed by 20000x11 matrix. I do not want to import all of these data. How can I plot graph of the column 1 & column 4? 
[plotting] [import]
 

asked by Gokce https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1297 Score of 21

answered by user1066 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=106 Score of 24

8.40.2.3 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 Score of 23

answered by J. M.'s persistent exhaustion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 Score of 17

8.40.2.4 How can I draw the Olympic rings with Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8885

How can I draw the 5 interlocking Olympic rings with Mathematica? 
(SVG version) 
Edit 
 
Hard choice, but some pretty cool answers here. I didn't have 3D answers in mind when I posted the question, but ... 
[graphics] [generative-art]
 

asked by Mike Honeychurch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77 Score of 47

answered by cormullion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61 Score of 23

8.40.2.5 How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66273

I'm trying to expedite some quantum mechanical calculations (expectation values etc.) by running them through Mathematica. When I say, for example, 
... 
[functions] [complex] [assumptions] [variable-definitions]
 

asked by Matthew Brunetti https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22304 Score of 53

answered by SquareOne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19960 Score of 34

8.40.2.6 xkcd-style Plots

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350

I received an email to which I wanted to respond with a xkcd-style graph, but I couldn't manage it. Everything I drew looked perfect, and I don't have enough command over ... 
[plotting] [generative-art]
 

asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 Score of 636

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 Score of 499

8.40.2.7 How to calculate scalar curvature, Ricci tensor and Christoffel symbols in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8895

I am seeking a convenient and effective way to calculate such geometric quantities. I've used packages like  TensoriaCalc , but they don't work at all time. Sometimes,... 
[symbolic] [physics] [tensors] [differential-geometry]
 

asked by Zoe Rowa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1713 Score of 48

answered by Yi-Zen Chu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4869 Score of 24