[with patch, positive review] 2d-plots has no functionality for grid lines

[saliola]

It would be nice to be able to add grids to 2d plots in Sage.

[saliola]

Here is a patch. Based on code by Sébastien Labbé, so give him credit as well please.

[was]

REVIEW:

• The gridlines option docstring in show is not nicely aligned like all the other ones; they also look like a mess in ClassGridLines?:

  ...
              axes         -- (default: True)
              axes_labels  -- (default: None) list (or tuple) of two strings;
                              the first is used as the label for the horizontal
                              axis, and the second for the vertical axis.
              fontsize     -- (default: current setting -- 10) positive
                              integer; used for axes labels; if you make
                              this very large, you may have to increase
                              figsize to see all labels.
              frame        -- (default: False) draw a frame around the image
              gridlines -- (default: None) can be any one of the following:
                  None, False -- do not add grid lines
                  True, "automatic", "major" -- add grid at major ticks
                      of axes
                  "minor" -- add grid at major and minor ticks of axes
                  [xlist,ylist] -- a tuple or list containing two elements,
                      where xlist (or ylist) can be any of the following:
                      None, False -- don't add horizontal (or vertical) lines
                      True, "automatic", "major" -- add horizontal (or
                          vertical) grid lines at the major ticks of axes
                      "minor" -- add horizontal (or vertical) grid lines
                          at major and minor ticks of axes
                      iterable yielding numbers n or pairs (n,opts) where
                          n is the coordinate of the line and opt is a
                          dictionary of MATPLOTLIB options for rendering the
                          line.
  

• This works:

              sage: f = lambda x,y: sin(x^2 + y^2)*cos(x)*sin(y)
              sage: c = contour_plot(f, (-4, 4), (-4, 4), plot_points=15)
              sage: c.show(gridlines=True, gridlinesstyle={'linestyle':'--','linewidth':1, 'color':'red'})
  

but this doesn't:

            sage: f = lambda x,y: sin(x^2 + y^2)*cos(x)*sin(y)
            sage: c = contour_plot(f, (-4, 4), (-4, 4), plot_points=15)
            sage: c.show(gridlines=True, gridlinesstyle={'linestyle':'--','linewidth':1, 'rgbcolor':'red'})

Basically rgbcolor is annoyingly a synonym for color everywhere. But it should be supported.

• In fact,

  line([(0,0), (1,2)], color='red')
  

lamely doesn't even work (though I hope somebody posts a patch to fix this).

• For completeness can you add INPUT: and OUTPUT: blocks to

   	636	    def add_gridlines(self, subplot, xmin, xmax, ymin, ymax, frame=False): 
   	637	        # Process the input to get valid gridline data. 
   	638	        r""" 
   	639	        Add the grid lines to a subplot object. 
   	640	 
  

Just make the above very minor polish as a subsequent patch to yours and ... POSITIVE REVIEW.

[saliola]

Cleaned up the docstring (in both places).

            fontsize     -- (default: current setting -- 10) positive
                            integer; used for axes labels; if you make
                            this very large, you may have to increase
                            figsize to see all labels.
            frame        -- (default: False) draw a frame around the image
            gridlines    -- (default: None) can be any of the following:
                            1. None, False: do not add grid lines.
                            2. True, "automatic", "major": add grid lines
                               at major ticks of the axes.
                            3. "minor": add grid at major and minor ticks.
                            4. [xlist,ylist]: a tuple or list containing
                               two elements, where xlist (or ylist) can be
                               any of the following.
                               4a. None, False: don't add horizontal (or
                                   vertical) lines.
                               4b. True, "automatic", "major": add
                                   horizontal (or vertical) grid lines at
                                   the major ticks of the axes.
                               4c. "minor": add horizontal (or vertical)
                                   grid lines at major and minor ticks of
                                   axes.
                               4d. an iterable yielding numbers n or pairs
                                   (n,opts), where n is the coordinate of
                                   the line and opt is a dictionary of
                                   MATPLOTLIB options for rendering the
                                   line.
            gridlinesstyle,
            hgridlinesstyle,
            vgridlinesstyle 
                         -- (default: None) a dictionary of MATPLOTLIB
                            options for the rendering of the grid lines,
                            the horizontal grid lines or the vertical grid
                            lines, respectively.

Support for rgbcolor added; both examples work; changed some of the color keywords in the doctests to rgbcolor so it gets tested.

Added INPUT and OUTPUT blocks.

[saliola]

patch with changes made after review

[was]

Looks good now.

[mabshoff]

Unfortunately this patch needs to be rebased against 3.1.rc0:

mabshoff@sage:/scratch/mabshoff/release-cycle/sage-3.1.rc0/devel/sage$ patch -p1 < trac_3813-anakha-adaptive-plot-v3.patch 
patching file sage/plot/plot.py
Hunk #1 succeeded at 3449 (offset 35 lines).
Hunk #2 succeeded at 3504 (offset 35 lines).
Hunk #3 succeeded at 3531 (offset 35 lines).
Hunk #4 succeeded at 3599 (offset 35 lines).
Hunk #5 succeeded at 3679 (offset 46 lines).
Hunk #6 FAILED at 3704.
Hunk #7 FAILED at 4536.
2 out of 7 hunks FAILED -- saving rejects to file sage/plot/plot.py.rej

[mabshoff]

Opps, the above was meant for #3813. The two patches on this ticket do apply cleanly.

Cheers,

Michael

[mabshoff]

Merged trac_3825-gridlines.patch and trac_3825-gridlines-2.patch in Sage 3.1.rc0