Feature Request: Error Bar Plots

[maxnoe]

For scientists one hugely important feature would be plots with error bars und lower/upper limits like these:

http://matplotlib.org/examples/statistics/errorbar_limits.html

Also see this stackexchange question:
http://stackoverflow.com/questions/29166353/how-do-you-add-error-bars-to-bokeh-plots-in-python

[maxnoe]

Any news on this?

[michaelaye]

👍

[bsipocz]

👍

And thanks to @maxnoe for the SO answer, that will do until it gets built in.

[bsipocz]

Now looking into it more closely, the SO solution is not working with interactive plots. Back to square one.

[maxnoe]

What's the problem?

[bsipocz]

errorbar(pp, x='hjd', y='flux', xerr='fluxerr', source=s2)

​source.callback = CustomJS(args=dict(s2=s2), code="""
        var inds = cb_obj.get('selected')['1d'].indices;
        var d1 = cb_obj.get('data');

​        s2.get('data')['hjd'] = d1['hjd'][inds[0]]
        s2.get('data')['flux'] = d1['flux'][inds[0]]
        s2.get('data')['fluxerr'] = d1['fluxerr'][inds[0]]

        cb_obj.trigger('change');
        s2.trigger('change');
    """)

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-38-524c4b97c72f> in <module>()
     30 #    pp.line(hjd[i], flux[i])
     31 
---> 32 errorbar(pp, x='hjd', y='flux', xerr='fluxerr', source=s2)
     33 
     34 source.callback = CustomJS(args=dict(s2=s2), code="""

<ipython-input-29-ce33a5d4f725> in errorbar(fig, x, y, xerr, yerr, color, source, point_kwargs, error_kwargs)
      7       x_err_y = []
      8       for px, py, err in zip(x, y, xerr):
----> 9           x_err_x.append((px - err, px + err))
     10           x_err_y.append((py, py))
     11       fig.multi_line(x_err_x, x_err_y, color=color, source=source, **error_kwargs)

TypeError: unsupported operand type(s) for -: 'str' and 'str'

[maxnoe]

You need to give it the data as something iterable.

[jacopo-chevallard]

+1

[andyfaff]

+1

[StevenCHowell]

+1

[Apfelkuchen]

+1

[kippvs]

+1

[StevenCHowell]

@bokeh/dev, has there been consideration as to plotting errorbars? Would this be best in plotting.figure.errorbar, i.e., as a glyph similar to circle?

This method produces a nice result by wrapping existing code:

def errorbar(fig, x, y, xerr=None, yerr=None, color='red', 
             point_kwargs={}, error_kwargs={}):

    fig.circle(x, y, color=color, **point_kwargs)

    if xerr is not None:
        x_err_x = []
        x_err_y = []
        for px, py, err in zip(x, y, xerr):
            x_err_x.append((px - err, px + err))
            x_err_y.append((py, py))
        fig.multi_line(x_err_x, x_err_y, color=color, **error_kwargs)

    if yerr is not None:
        y_err_x = []
        y_err_y = []
        for px, py, err in zip(x, y, yerr):
            y_err_x.append((px, px))
            y_err_y.append((py - err, py + err))
        fig.multi_line(y_err_x, y_err_y, color=color, **error_kwargs)

I am thinking to try to implement this though it may take me a few weeks to get the time to fully complete it. Please comment with any thoughts/recommendations.