save method for graphics objects does not have an example explicitly using "save"

[sagetrac-ljpk]

The examples in the documentation for the save method seems to be broken. If I try

sage: E=EllipticCurve([1,0])
sage: Eplot=E.plot()
sage: Eplot.save?

then I get

EXAMPLES:
                sage: c = circle((1,1),1,rgbcolor=(1,0,0))
                sage: c.show(xmin=-1,xmax=3,ymin=-1,ymax=3)

                To correct the apect ratio of certain graphics, it is necessary
                to show with a 'figsize' of square dimensions.

                sage: c.show(figsize=[5,5],xmin=-1,xmax=3,ymin=-1,ymax=3)

                sage: point((-1,1),pointsize=30, rgbcolor=(1,0,0))

which never mentions "save" at all. Presumably there should be an extra line, something like

sage: c.save("example.png")

CC: @mwhansen

Component: documentation

Author: Jason Grout

Reviewer: Mike Hansen

Merged: sage-4.3.2.alpha0

Issue created by migration from https://trac.sagemath.org/ticket/4689

[sagetrac-mabshoff]

comment:1

Hi,

which Sage release is that? If it is 3.2.1 this might be #4672. There is a patch over there that needs one doctest fix to be merged into 3.2.2.

Cheers,

Michael

[sagetrac-ljpk]

comment:3

It's in both 3.1.4 and 3.2.1, but that bug report does look relevant; hopefully fixing that will sort this out too.

[sagetrac-mabshoff]

comment:4

With #4672 appplied:

mabshoff@sage:/scratch/mabshoff/release-cycle/sage-3.2.2.alpha0$ ./sage
----------------------------------------------------------------------
| Sage Version 3.2.1, Release Date: 2008-12-01                       |
| Type notebook() for the GUI, and license() for information.        |
----------------------------------------------------------------------
sage: E=EllipticCurve([1,0])
sage: Eplot=E.plot()
sage: Eplot.save?

results in

Type:           instancemethod
Base Class:     <type 'instancemethod'>
String Form:    <bound method Graphics.save of >
Namespace:      Interactive
File:           /scratch/mabshoff/release-cycle/sage-3.2.2.alpha0/local/lib/python2.5/site-packages/sage/plot/plot.py
Definition:     Eplot.save(self, filename=None, xmin=None, xmax=None, ymin=None, ymax=None, figsize=(6, 3.7082039324993699), figure=None, sub=None, savenow=True, dpi=100, axes=None, axes_labels=None, fontsize=None, frame=False, verify=True, aspect_ratio=None, gridlines=None, gridlinesstyle=None, vgridlinesstyle=None, hgridlinesstyle=None)
Docstring:
    
            Save the graphics to an image file of type: PNG, PS, EPS, SVG, SOBJ,
            depending on the file extension you give the filename.
                Extension types can be: file{.png}, file{.ps}, file{.eps}, file{.svg},
                and file{.sobj} (for a SAGE object you can load later). 
    
            EXAMPLES:
                sage: c = circle((1,1),1,rgbcolor=(1,0,0))
                sage: c.show(xmin=-1,xmax=3,ymin=-1,ymax=3)
    
                To correct the apect ratio of certain graphics, it is necessary
                to show with a 'figsize' of square dimensions.
    
                sage: c.show(figsize=[5,5],xmin=-1,xmax=3,ymin=-1,ymax=3)
                
                sage: point((-1,1),pointsize=30, rgbcolor=(1,0,0))

Rereading the original ticket I now get your main point: the docstring does not contain "save", but "show" does save the png and then pops up a viewer. We could resolve this by adding a example that uses the save method as you suggested, but my guess would be that such example (in case it did exist) was either changed or removed since "save('foo.png')" saves in the current working directory which is bad for doctesting as a non-owner.

So, what do you want to do? Close this ticket as "wontfix" or we add a doctest that saves an image in SAGE_TMP - which is the clean way to deal with temporary files.

Cheers,

Michael

[sagetrac-ljpk]

comment:5

I think your idea of having a doctest which saves an image somewhere temporary would be the best idea as it would give the reader the idea of how to use the method and reassure them that it is the correct help function.

[jasongrout]

Attachment: trac-4689-save-docstring.patch.gz

[jasongrout]

Author: Jason Grout