Can we use tex in labels / titles ?

[BowenFu]

Something like
(plot (function sin (- pi) pi #:label "y = \sin(x^2)"))?

[soegaard]

Den lør. 15. feb. 2020 kl. 05.48 skrev Bowen Fu <notifications@github.com>:

Something like (plot (function sin (- pi) pi #:label "y = \sin(x^2)"))? [image: untitled] <https://user-images.githubusercontent.com/5812640/74582019-5a5d5480-4ff1-11ea-8995-7deff69d1ca5.png>

I offer one piece of the puzzle, namely a function that turns a string containing latex formula into a `pict`: https://github.com/soegaard/latex-pict It relies on `racket-poppler` which contains bindings for Poppler (a library for drawing pdfs using Cairo - which is the graphics engine Racket uses). Note that `plot` offers `plot/dc` which allows you to draw the plot on a drawing context `dc`. This makes it possible to combine picts and plots. For approximate placement of labels, I think this is enough. If you need to place labels using plot coordinates, then some work needs to be done: a function to convert dc coordinates to plot coordinates (and vice versa) needs to be written. The tricky bit is that plot (when given a width and height) uses some of the same for margins and labels. How much space is determined here(ish): https://github.com/racket/plot/blob/9823d1ab9ff9144a8a3114afc0af6a69a0fbc4b7/plot-lib/plot/private/plot2d/plot-area.rkt#L533 I think, this needs to be added to `plot` itself (correct me if I am wrong). /Jens Axel

[alex-hhh]

You can use unicode characters for some math notation. this is not as flexible as using TeX, but can be useful in a lot of cases:

#lang racket
(require plot)
(plot (function sin (- pi) pi #:label "y = sin(x²)"))

Produces:

[alex-hhh]

As for the implementation, the #label argument to the plot functions can be extended to accept a pict argument in addition to a string. There is already a point-pict function which can display pict objects on a plot.

This way, the latex-pict package suggested above could be used to render the labels.