Error bars not showing up in Bar

Kasia_Rachuta · April 17, 2017, 10:38pm

I’m plotting a Bar chart and I want to add error bars. I have used this: http://stackoverflow.com/questions/29166353/how-do-you-add-error-bars-to-bokeh-plots-in-python

but for some reason, despite adding the code below, I’m still not getting the error bars to show up. The Bar chart shows up as expected. Please advise. I’m not including my DataFrame to preserve confidentiality but I could perhaps erase some of the entries if that would make things easier.

p = Bar(all_contracts, values=’%_saved’, label=‘contract_type’, plot_width=450, plot_height=450,

ylabel = ‘Percentage saved’, xlabel = ‘Contract type’, tools=False, outline_line_alpha=0, line_color=‘white’,

notebook=True, color=‘grey’, fill_alpha=0.3)

p.legend.location = None

p.xgrid.grid_line_color = None

p.ygrid.grid_line_color = None

p.xaxis.major_tick_in = 0

p.xaxis.major_tick_out = 0

p.axis.minor_tick_in = 0

p.axis.minor_tick_out = 0

ys = all_contracts[’%_saved’]

xs = all_contracts[‘contract_type’]

create the coordinates for the errorbars

err_xs =

err_ys =

for x, y, yerr in zip(xs, ys, yerrs): # Also took out yerr from this line but that didn’t help much.

err_xs.append((x, x))

err_ys.append((all_contracts[‘lower_ci’], all_contracts[‘upper_ci’]))

plot them

p.multi_line(err_xs, err_ys, color=‘red’)

show(p)

Tyler_Nickerson · April 21, 2017, 4:32pm

It looks like the issue is in the last line of this for loop.

for x, y, yerr in zip(xs, ys, yerrs): err_xs.append((x, x))
err_ys.append((all_contracts['lower_ci'], all_contracts['upper_ci']))

If you inspect err_xs it should look something like this:

[(xs[1], xs[1]), (xs[2], xs[2]), ..., (xs[n], xs[n])]

err_ys on the other hand should look something like:

[(all_contracts['lower_ci'], all_contract['upper_ci']), (all_contracts['lower_ci'], all_contracts['upper_ci']), ..., (all_contracts['lower_ci'], all_contracst['upper_ci'])]

This is likely not what you wanted. Try something like this instead:

ys = all_contracts['%_saved']
xs = all_contracts['contract_type']
err_hi = all_contracts['upper_ci']
err_lo = all_contracts['lower_ci'
]
# create the coordinates for the errorbars
err_xs = []
err_ys = []
for x, y, erl, erh in zip(xs, ys, err_lo, err_hi):
# this didn't work with lists of tuples for me,
    # I changed them to lists of lists.. ymmv
    err_xs.append([x, x])
err_ys.append([erl, erh])

···

On Mon, Apr 17, 2017 at 3:38 PM, Kasia Rachuta [email protected] wrote: