matplotlib-users Mailing List for matplotlib

>>>>> "Richard" == Richard Taylor <rt...@ec...> writes:

    Richard> I recently upgraded to the binary for Windows version
    Richard> 0.60.2 and found that the plus (+) symbol always plots in
    Richard> black even though a color is specified.  My fix was to
    Richard> change the parameter lines.markeredgecolor to the color I
    Richard> wanted using the rc() command and then to revert to the
    Richard> default using rcdefaults().  This works ok for me but I
    Richard> thought you might want to know in case it's a bug.

Yes, this is a bug, sort of.  '+' is a marker.  In the current
matplotlib, the colorarg only sets the marker face color but not the
edge color.  For circles and the like, this is normally not a
problem.  But for '+' it makes no sense.

In the next release, color args will affect both the edge and face
colors, and you can override this by providing a kwarg, eg

  >>> plot(range(10), 'r+')  # red plusses

  >>> plot(range(10), 'ro')  # red circles, edge and face

  >>> plot(range(10), 'ro', markeredgecolor='k')  # red face, black edge

Thanks for letting me know.

JDH

I recently upgraded to the binary for Windows version 0.60.2 and found that
the plus (+) symbol always plots in black even though a color is specified.
My fix was to change the parameter lines.markeredgecolor to the color I
wanted using the rc() command and then to revert to the default using
rcdefaults().  This works ok for me but I thought you might want to know in
case it's a bug.

 

Regards,

Rich

>>>>> "Stephen" == Stephen Walton <ste...@cs...> writes:

    Stephen> However, in either case, the bars' left edge is at the x
    Stephen> coordinate rather than being centered on it.  I know this
    Stephen> is the documented behavior, but Matlab centers the bars
    Stephen> on the given X coordinates.  How do people feel about
    Stephen> changing matplotlib to match the Matlab behavior?  I've
    Stephen> changed my copy locally.

Hi Stephen,
I'd be happy with this change.  I CCd Gary Ruben who has done a lot of
work on the bar function because he'll likely have an opinion.

If you could send me your code, I'll look into merging it if all
agree this is the desired behavior.

JDH

Personally, I agree with Stephen that "center the bar on the given x value" is 
more user friendly.

JC Hsu

On Thu, 2004-08-05 at 10:00, John Hunter wrote:
> >>>>> "Jin-chung" =3D=3D Jin-chung Hsu <hs...@st...> writes:
>=20
>     Jin-chung> When I do the bar(left, height) in matlab the first
>     Jin-chung> time, e.g.:
>     >>>> bar([4,5,6,7,8],[9,8,7,6,5])
>=20

> This was a bug in the way I update the datalim in axes.py, which is
> currently a bit too fragile for my tastes.  Below I'll include the
> modified matplotlib.axes.Axes.bar function.  Let me know if it passes
> all your tests...

I was interested in this report, and sorry if I butted in.  John's patch
fixes Jin-chung's problem with poor x-axis scaling here.  I'm using CVS,
not 0.60.2, and didn't see the "funny Y tick labels" he reported.

However, in either case, the bars' left edge is at the x coordinate
rather than being centered on it.  I know this is the documented
behavior, but Matlab centers the bars on the given X coordinates.  How
do people feel about changing matplotlib to match the Matlab behavior?=20
I've changed my copy locally.

--=20
Stephen Walton <ste...@cs...>
Dept. of Physics & Astronomy, Cal State Northridge

>>>>> "Jin-chung" == Jin-chung Hsu <hs...@st...> writes:

    Jin-chung> When I do the bar(left, height) in matlab the first
    Jin-chung> time, e.g.:
    >>>> bar([4,5,6,7,8],[9,8,7,6,5])

Hi, thanks for the report.

This was a bug in the way I update the datalim in axes.py, which is
currently a bit too fragile for my tastes.  Below I'll include the
modified matplotlib.axes.Axes.bar function.  Let me know if it passes
all your tests...

Cheers,
JDH

    def bar(self, left, height, width=0.8, bottom=0,
            color='b', yerr=None, xerr=None, ecolor='k', capsize=3
            ):
        """
        BAR(left, height)
        
        Make a bar plot with rectangles at
          left, left+width, 0, height
        left and height are Numeric arrays

        Return value is a list of Rectangle patch instances

        BAR(left, height, width, bottom,
            color, yerr, xerr, capsize, yoff)

        xerr and yerr, if not None, will be used to generate errorbars
        on the bar chart

        color specifies the color of the bar
        ecolor specifies the color of any errorbar

        capsize determines the length in points of the error bar caps

        
        The optional arguments color, width and bottom can be either
        scalars or len(x) sequences

        This enables you to use bar as the basis for stacked bar
        charts, or candlestick plots
        """
        if not self._hold: self.cla()
        
        left = asarray(left)
        height = asarray(height)

        patches = []


        # if color looks like a color string, and RGB tuple or a
        # scalar, then repeat it by len(x)
        if (is_string_like(color) or
            (iterable(color) and len(color)==3 and len(left)!=3) or
            not iterable(color)):
            color = [color]*len(left)


        if not iterable(bottom):
            bottom = array([bottom]*len(left), Float)
        else:
            bottom = asarray(bottom)
        if not iterable(width):
            width = array([width]*len(left), Float)
        else:
            width = asarray(width)

        N = len(left)
        assert len(bottom)==N, 'bar arg bottom must be len(left)'
        assert len(width)==N, 'bar arg width must be len(left) or scalar'
        assert len(height)==N, 'bar arg height must be len(left) or scalar'
        assert len(color)==N, 'bar arg color must be len(left) or scalar'

        right = left + width
        top = bottom + height
        

        args = zip(left, bottom, width, height, color)
        for l, b, w, h, c in args:            
            if h<0:
                b += h
                h = abs(h)
            r = Rectangle(
                xy=(l, b), width=w, height=h,
                facecolor=c,
                )
            self.add_patch(r)
            patches.append(r)
 

        if xerr is not None or yerr is not None:
            self.errorbar(
                left+0.5*width, bottom+height,
                yerr=yerr, xerr=xerr,
                fmt=None, ecolor=ecolor, capsize=capsize)
        self.autoscale_view()
        return patches