9.37.2 Greatest hits from previous weeks

9.37.2.1 How to calculate scalar curvature, Ricci tensor and Christoffel symbols in Mathematica?
9.37.2.2 How to plot an ellipse?
9.37.2.3 xkcd-style Plots
9.37.2.4 Placing text within a plot
9.37.2.5 Is it possible to export the equations from Mathematica to MATLAB?
9.37.2.6 How to manipulate 2D plots?
9.37.2.7 Figuring when the minute and hour hand coincide on a clock
9.37.2.1 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 52
answered by Yi-Zen Chu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4869 Score of 25
9.37.2.2 How to plot an ellipse?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100

I'm new to Mathematica, and I'm finding it difficult to plot an ellipse. 
I tried using 
 
 Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}] 
 
 
but I'm getting ... 
[plotting]
 
asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 Score of 19
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 Score of 33
9.37.2.3 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 639
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 Score of 503
9.37.2.4 Placing text within a plot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=71776

I want to place text within a plot. The text is always centered relative to the coordinates. How can I left-align or right-align the text relative to the coordinates? For example: 
 
... 
[plotting] [graphics] [text]
 
asked by Anthony Mannucci https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24733 Score of 27
answered by m_goldberg https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3066 Score of 12
9.37.2.5 Is it possible to export the equations from Mathematica to MATLAB?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14035

Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax? 
[export] [matlab]
 
asked by Seyhmus Güngören https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4256 Score of 47
answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 Score of 51
9.37.2.6 How to manipulate 2D plots?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=7142

When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ... 
[plotting] [graphics] [dynamic] [gui-construction]
 
asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 Score of 145
answered by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 Score of 164
9.37.2.7 Figuring when the minute and hour hand coincide on a clock

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573

I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely.  This is really a question about three distinct things - to be done in Mathematica ... 
[equation-solving]
 
asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 Score of 16
answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 Score of 22