documentation mistake in errorbar

[oliverw1]

Copying this from the mpl mailinglist item.

When using errorbar, the documentation says the color of the errorbar lines will match with the color of the markers if ecolor=None. That’s not what I found. Apparently it takes over the color of the Line2D instance which interconnects the markers.

Short, Self Contained, Correct Example:

from pylab import *
plt.ion()  # saves typing show

x = np.arange(10)
y = np.random.rand(10)
xerr, yerr = y/4., y/4.

# Markers in red, but errorlines assume the color of the "trendline" (default rcparams: blue).
errorbar(x, y, yerr=yerr, mfc='r', marker='o', ecolor=None) 

# Errorlines get color green now - documentation not in line with results

figure(); errorbar(x, y, yerr=xerr, mfc='r', marker='o', ecolor=None, color='g')
# Errorlines get color blue now, because it can be specified - expected behaviour
figure(); errorbar(x, y, yerr=xerr, mfc='r', marker='o', ecolor='b', color='g')

I don't know what the original design decision was: to make sure the errorbarlines get the same color as the markers or if they should get the same color as the "trendline". In the latter case, only the documentation needs to be fixed (although I'm sure fixing the code will be just as easy in this case).

[tacaswell]

@oliverw1 Could you put together a pull request to correct the documentation?

[oliverw1]

Will do.

[tacaswell]

@oliverw1 Did I miss the PR for this?

[oliverw1]

My apologies - I lost sight of this because my old laptop died. Also, this is my first pull request, so I hope I followed the mpl guidelines (I didn't branch off the maintenance though, sorry). Feel free to educate me in my wrong-doings. :)

[tacaswell]

Don't worry, I don't think we plan to do a 1.3.2, and it can always be back-ported.