11.39.2 Greatest hits from previous weeks

11.39.2.1 Why round to even integers?
11.39.2.2 Elegant operations on matrix rows and columns
11.39.2.3 Generate a Unit Circle Trigonometry
11.39.2.4 Plotting Complex Quantity Functions
11.39.2.5 How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc
11.39.2.6 How do I plot a plane EM wave?
11.39.2.7 How to create a histogram from a given frequency table
11.39.2.1 Why round to even integers?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2116

According to the Mathematica help: 
Round rounds numbers of the form x.5 toward the nearest even integer. 
For example: 
 
 Round[{0.5, 1.5, 2.5, 3.5, 4.5}] 
 
 
gives 
 
<... 
[numerics] [language-design]
 
asked by wxffles https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=427 Score of 88
answered by Per Alexandersson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=488 Score of 55
11.39.2.2 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 208
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 Score of 70
11.39.2.3 Generate a Unit Circle Trigonometry

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456

Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data : 
[graphics] [labeling] [trigonometry] [mapthread]
 
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 Score of 22
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 Score of 36
11.39.2.4 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
11.39.2.5 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 57
answered by SquareOne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19960 Score of 42
11.39.2.6 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 25
answered by J. M.'s missing motivation https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 Score of 18
11.39.2.7 How to create a histogram from a given frequency table

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=70059

I wanted to draw a histogram as in the photo above, I typed the command: 
 
... 
[plotting] [histograms]
 
asked by Perw https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23500 Score of 4
answered by bbgodfrey https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1063 Score of 7