matplotlib-devel Mailing List for matplotlib

>>>>> "Paul" == Paul Barrett <ba...@st...> writes:


    Paul> This was an easy change to the font manager.  You should see
    Paul> it in CVS later today.

Great.

An unrelated bug I found in testing with one of my apps

In the font_manager

    def get_size_in_points(self, parent_size=None):
        """Convert text to point size"""
        if isinstance(self.__size, str):
            if   self.__size == 'larger':
                size = int(self.__parent_size*1.2)
            elif self.__size == 'smaller':
                size = int(self.__parent_size/1.2)
            else:
                defsize = fontManager.get_default_size()
                size = defsize*font_scalings[self.__size]
            return size
        else:
            return self.__size

I sometimes get key error on font_scalings[self.__size] when
self.__size is a number, eg 10.  From the code, it looks like you
intend self.__size to always be a relative size.  I did a temporary
workaround along the lines of

            else:
                try: size = float(self.__size)
                except ValueError:
                    defsize = fontManager.get_default_size()
                    size = defsize*font_scalings[self.__size]
            return size

but this hack may be masking another bug so I thought you'd want to
look into it.

    Paul> On a related issue, I noticed that the sizes of PS plots are
    Paul> different depending on which backend is used first.  If I
    Paul> send a plot directly to the PS backend, I get a nice plot
    Paul> (see the attachment simple_plot_PS.ps).  Whereas, if I first
    Paul> display the plot using TkAgg and then save it to PS, I get a
    Paul> plot that is much larger than the display area (see the
    Paul> attachment simple_plot.ps).  The text size in both plots
    Paul> appears to be the same size, this would indicate an
    Paul> incorrect scaling factor somewhere.

backend_tkagg needs to override FigureCanvasTkAgg.print_figure
following the lead of backend_gtkagg.  The critical point is that dpi
must be set to 72 for backend_ps.  Even though ps doesn't use DPI,
this value is used by the figure to compute the canvas size as
width*dpi and height*dpi, and this does affect backend_ps.

In FigureCanvaseGTKAgg.print_figure I save the orig dpi, set the
figure dpi to 72, print the figure, and then reset.  I do the same
with other figure properties (eg, background color, so you can have a
different color background for printing and GUI).

It should be mostly a cut and paste from backend_gtkagg.

JDH

John Hunter wrote:
> 
> Another concern I have is that if I am reading the code correctly all
> the afm files are being parsed at load time, even for non-postscript
> backends.  Some users have hundreds of afm files in their path, and on
> a slowish machine this can impose a substantial performance hit.  In
> the past, I deferred parsing the afm files for the non-ps backends
> until they were called for, eg, until a call to
> savefig('somefile.ps').  Don't know if this is easy or possible to
> incorporate in the current design, but it's something to think about.

Hi John,

This was an easy change to the font manager.  You should see it in CVS later today.

On a related issue, I noticed that the sizes of PS plots are different depending 
on which backend is used first.  If I send a plot directly to the PS backend, I 
get a nice plot (see the attachment simple_plot_PS.ps).  Whereas, if I first 
display the plot using TkAgg and then save it to PS, I get a plot that is much 
larger than the display area (see the attachment simple_plot.ps).  The text size 
in both plots appears to be the same size, this would indicate an incorrect 
scaling factor somewhere.

  -- Paul

-- 
Paul Barrett, PhD      Space Telescope Science Institute
Phone: 410-338-4475    ESS/Science Software Branch
FAX:   410-338-4767    Baltimore, MD 21218