Get information from embedded bokeh plot

Question

I have a streaming bokeh plot that I have embedded into a flask rendered HTML document. I used this repo as a guide for how to link up my flask server and my bokeh server. Now that I have the streaming plot online, I want to show some calculations on the streaming data beneath the plot (i.e. average point, differential, standard deviation) What is the best way to access the plot data source to do those calculations?

My googling shows that bokeh doesn't have a good way to put a text box in the embedded bokeh document, so that means I'd need to pull the data into the flask template somehow so I can manipulate it with jquery?

How would experienced coders start to approach the problem, or maybe someone knows a project that has tackled this issue I could take a look at? Thanks!

score 1 · Answer 1 · edited May 23 '17 at 12:17

Great news! Turns out bokeh does have a way to add text to a document. I was able to solve my problem with Paragraph()

So for example I could modify this streaming example to the following:

from bokeh.plotting import figure, curdoc
from bokeh.driving import linear
from bokeh.models import Paragraph
from bokeh.layouts import column
import random

p = figure( plot_width=300, plot_height=300)
r1 = p.line([], [], color="firebrick", line_width=2)
r2 = p.line([], [], color="navy", line_width=2)
ds1 = r1.data_source
ds2 = r2.data_source
avg1 = Paragraph(text='Average Val #1 is:')
avg2 = Paragraph(text='Average Val #2 is:')

@linear()
def update(step):
    ds1.data['x'].append(step)
    ds1.data['y'].append(random.randint(0, 100))
    ds2.data['x'].append(step)
    ds2.data['y'].append(random.randint(0, 100))
    ds1.trigger('data', ds1.data, ds1.data)
    ds2.trigger('data', ds2.data, ds2.data)
    mean1 = sum(ds1.data['x'])/float(len(ds1.data['x']))
    mean2 = sum(ds2.data['x'])/float(len(ds2.data['x']))
    avg1.text = 'Average Val #2 is: ' + str(mean1)
    avg2.text = 'Average Val #2 is: ' + str(mean2)
curdoc().add_root(column(p,avg1,avg2))

# Add a periodic callback to be run every 500 milliseconds
curdoc().add_periodic_callback(update, 500)

Get information from embedded bokeh plot

1 Answers1