9.27.2 Greatest hits from previous weeks

9.27.2.1 Get a "step-by-step" evaluation in Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=148

Is it possible in Mathematica to get a step-by-step evaluation of some functions; that's to say, outputting not only the result but all the stages that have led to it? If so, how does one do it? 
 
... 
[evaluation] [interactive] [faq]
 

asked by Cydonia7 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44 Score of 142

answered by J. M.'s lack of A.I. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 Score of 117

9.27.2.2 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 51

answered by Yi-Zen Chu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4869 Score of 25

9.27.2.3 How can I plot implicit equations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34668

If you enter the following into Wolfram | Alpha, you get nice graphs: 
 
 graph 4 x^4 + y^2 = 2 
 
How do you do this in Mathmatica? I realize that these are not ... 
[plotting] [faq]
 

asked by Rollie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10174 Score of 42

answered by Timothy Wofford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9391 Score of 44

9.27.2.4 Plotting a Phase Portrait

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14160

I'm trying to plot a phase portrait for the differential equation 
$$x'' - (1 - x^2) x' + x = 0.5 \cos(1.1 t)\,.$$ 
The primes are derivatives with respect to $t$. I've reduced this second order ODE to ... 
[plotting] [differential-equations]
 

asked by covertbob https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4528 Score of 45

answered by David Slater https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1746 Score of 41

9.27.2.5 Elegant operations on matrix rows and columns

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3069

Question 
 
The Mathematica tutorial has a section 'Basic Matrix Operations', describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ... 
[matrix] [list-manipulation] [faq]
 

asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 Score of 198

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 Score of 66

9.27.2.6 Where is Abbott? How to make logograms from the film "Arrival"?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=137156

The film Arrival showed Wolfram Language code in action analysing alien logograms. A recent 
blog describes some details and 
mentions 
a live-coding video by Christopher Wolfam. See also Stephen Wolfram'... 
[graphics] [generative-art]
 

asked by KennyColnago https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3246 Score of 20

9.27.2.7 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 Score of 42

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