Asymmetric error bars are not supported for series (only dataframes)

[mizzao]

According to the documentation, asymmetric error bars should be able to be passed in to plot as an Mx2 array for a Series object or a Mx2xN array for a DataFrame object.

However, the code only seems to parse this correctly for a DataFrame: https://github.com/pydata/pandas/blob/master/pandas/tools/plotting.py#L1338

When passing raw error values as yerr, it seems that the first values are used as two-sided error differences, instead of being plotted as raw upper and lower values. Note the symmetric error bars below:

Using the underlying matplotlib function directly yields the expected results, but without the pandas-generated decorations:

This was originally noted in this StackOverflow question and I corroborated the other user's experience.

[ericmjl]

I am having a similar issue here.

[TomAugspurger]

Anyone interested in submitting a fix? I can help you out if you run into trouble.

[ericmjl]

I'm happy to try!

@TomAugspurger: I've been a user of pandas for a while, but I think I might need some guidance to the codebase. Would you be kind enough to pinpoint roughly where I should get started?

[TomAugspurger]

Thanks!

The plotting code is all in pandas/tools/plotting.py The logic for parsing error bars should all be here so that's were I'd start.