Plot multiple lines on a graph from ColumnDataSource

Question

I have two variables of the same unit I want to plot on the same x-axis with Bokeh. Seems like plot.multi_line is the right tool but I can't find the right syntax from the doc. What I tried (gathered from doc):

# df is a pandas DataFrame with contains 3 columns x, y1, y2

source = ColumnDataSource(data=df)
plot=figure()   
plot.multi_line(['x','x'], ['y1', 'y2'],  source=source)

Alternatively tried:

plot.multi_line(xs=['x','x'], ys=['y1', 'y2'],  source=source)

Results in

RuntimeError: Supplying a user-defined data source AND iterable values to glyph methods is not possibe. Either:

Pass all data directly as literals:

p.circe(x=a_list, y=an_array, ...)

Or, put all data in a ColumnDataSource and pass column names:

source = ColumnDataSource(data=dict(x=a_list, y=an_array)) p.circe(x='x', y='x', source=source, ...)

Doc give this example:

p.multi_line([[1, 3, 2], [3, 4, 6, 6]], [[2, 1, 4], [4, 7, 8, 5]],
         color=["firebrick", "navy"], alpha=[0.8, 0.3], line_width=4)

I obviously don't want to pass the values with raw lists. I don't get it, I need a little help.

Answer 1

Ok, I feel silly, simply doing:

source = ColumnDataSource(data=df)
plot=figure()   
plot.line('x','y1',  source=source, line_color="red")
plot.line('x','y2',  source=source, line_color="blue")

does the trick, as it would do in Matplotlib... I got confused with this "plot.multi_line" function (I now don't get why I would used that, but well).