未显示以 NaN Y 轴值开始或结束的散景图

Question

I am trying to get a graph that has all of the x-axis values filled but starts with y-axis values that are NaN. It appears that the graph will start at the first real y-axis value. Here is the example:

from bokeh.plotting import figure, output_file, show

output_file("line.html")
p = figure(plot_width=400, plot_height=400)

# add a line renderer with a NaN
n = float('nan')
p.line(
    [1, 2, 3, 4, 5], # x-axis
    [n, n, 7, 2, 4], # y-axis
    line_width=2
)
show(p)

This is the result:

As you can see the first 2 elements of the x-axis array aren't shown. I was hoping to find a way to force bokeh graph to show all values or a workaround to the same effect.

Answer 1

You could explicitly set the start (or end) of the plot's x (or y) axis. Like so:

from bokeh.plotting import figure, output_file, show

output_file("line.html")
p = figure(plot_width=400, plot_height=400)

# add a line renderer with a NaN
n = float('nan')
x_values = [1, 2, 3, 4, 5]  # x-axis
y_values = [n, n, 7, 2, 4]  # y-axis
p.line(x=x_values, y=y_values, line_width=2)

# of course in real life it'd make sense to do max and min of x and y,
# but this is all we need for your specific example.
p.x_range.start = min(x_values)

show(p)