I used to love programming in PostScript, around 25 years ago. I used the red, blue and green books, plus the PS Language Reference. This post prompted me to p

I used to love programming in PostScript, around 25 years ago. I used the red, blue and green books, plus the PS Language Reference. This post prompted me to put some of my old math notes up on GitHub [1]. The final chapter on coupled differential equations sends the DE's parameters to the PostScript printer, where my PS code would execute the different equations and directly draw the resulting phase portrait. My PS code is in that repo's README [1]. The final results are in the notes.pdf file [2]. The best examples are in the last few pages. [1] https://github.com/stevesimmons/maths132-notes https://github.com/stevesimmons/maths132-notes [2] https://github.com/stevesimmons/maths132-notes/blob/main/notes.pdf https://github.com/stevesimmons/maths132-notes/blob/main/not...