improve functionality of matrix_plot

[williamstein]

On Feb 16, 2008 10:19 PM, inerkor@gmail.com <inerkor@gmail.com> wrote:
> 
> Hello all.
> 
> I have a Matrix of, say, 64x64 and I plot it using matrix_plot(). It
> is a fractal that fills the square [0,1]x[0,1] so I want to keep a 2D
> view. I would like to change the x,y axes ranging values to be in the
> interval [0,1] rather than in {0, ..., 63}. I don't know how to do it.
> Maybe using another plotting function?.
> 

Nobody has implemented a simple clean way to do that in Sage yet,
though it would be easy to do.  Here is a hackish way to do exactly
what you want:

sage: a = random_matrix(RDF,64)
sage: import numpy
sage: m = matrix_plot(a)
sage: m[0].xrange =numpy.array([0,1],dtype=float)   # key part of all this
sage: m[0].yrange =numpy.array([0,1],dtype=float)
sage: m.xmax(1); m.ymax(1)
sage: m.show()

The above will be helpful to whoever does implement this.

 -- William

CC: @jasongrout @kcrisman

Component: graphics

Issue created by migration from https://trac.sagemath.org/ticket/2189

[sagetrac-whuss]

comment:1

The patch implements custom ranges, and adds the
options interpolation and alpha to matrix_plot.

It also fixes a few small bugs in the axes code
for matrix_plot.

Cheers,
Wilfried

[kcrisman]

comment:3

Attempted to apply this to 3.3.alpha0 but in the meantime _render_on_subplot method of class MatrixPlot (due to #4884) and the documentation for matrix_plot have both changed, so does not apply cleanly. Needs a rebase.

Nitpicks:

1. I think this patch might fix the crazy overlap between "49" and "50" in one of the first examples of matrix_plot,

sage: matrix_plot(random_matrix(RDF, 50), cmap='hsv')

which looks horrible, but that should be checked when this is rebased.
2. In axes.py, it would be great to fix the misspelling of "evaluate".
3. Possible request for improvement: the current behavior on the custom range seems to be floating point (is that correct?). Would it be possible to include custom ranges that were integer ranges, and (maybe) even ranges that actually labeled all integer values (as an option only, of course!)? This would be very helpful for examples such as plotting a non-random matrix over GF(p), such as a colored multiplication table or power table.

This will be very helpful, though, when complete, so thanks for the work!

[sagetrac-whuss]

Attachment: trac_2189.patch.gz

rebased for sage-3.3.alpha1