2.9.2 Greatest hits from previous weeks

2.9.2.1 Where can I find examples of good Mathematica programming practice?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18

I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...

asked by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 553 votes

answered by faysou https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66 486 votes

2.9.2.2 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 ...

asked by covertbob https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4528 38 votes

answered by David Slater https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1746 33 votes

2.9.2.3 How can I save both the plot and the legend together?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=35653

In this example, how can I put the legend inside the graph? Currently, when I save the graph, only the graph is saved, not the legend.

asked by Mika Ike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6543 42 votes

answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 38 votes

2.9.2.4 Find eigen energies of time-independent Schrödinger equation

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32293

I’m trying to get the eigenvalues of a one dimensional time-independent Schrödinger equation,

\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)

where U(x) is some potential and Ei is the ...

asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 48 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 46 votes

2.9.2.5 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 ...

asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 616 votes

answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 474 votes

2.9.2.6 How to create a new "person curve"?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=17704

Wolfram|Alpha has a whole collection of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica ...

asked by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 83 votes

answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 45 votes

2.9.2.7 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 ...

asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 17 votes

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 29 votes