如何在散景中更改箭头线的颜色？

Question

I want to draw an arrow between two points on a map using bokeh. I was able to do that with following code. I am able to change the color of arrow but not the color of line or the type of line dash. Looks like the properties exist only for the head. Is there a property to change color of the line and the line dash type (or) an alternate method to achieve the same?

from bokeh.plotting import figure, show, save
from bokeh.models import (Arrow, OpenHead)
from bokeh.io import curdoc, output_notebook, output_file, export_png
from bokeh.tile_providers import CARTODBPOSITRON_RETINA
from pyproj import Proj, transform

def latlonrange(lat1,lon1,lat2,lon2):
    p1 = Proj(init='epsg:4326')
    p2 = Proj(init='epsg:3857')    
    x1, y1 = transform(p1,p2,lon1,lat1)
    x2, y2 = transform(p1,p2,lon2,lat2)
    return {"x_range":(x1, x2), "y_range":(y1,y2)}   
def to_mercx(lat,lon):
    p1 = Proj(init='epsg:4326')
    p2 = Proj(init='epsg:3857')    
    x, y = transform(p1,p2,lon,lat)
    return x
def to_mercy(lat,lon):
    p1 = Proj(init='epsg:4326')
    p2 = Proj(init='epsg:3857')    
    x, y = transform(p1,p2,lon,lat)
    return y

curdoc().clear()
latlonbox = latlonrange(49.54, -127.28, 23.15, -66.24)
output_notebook()

p = figure(title="Map",
           x_range=latlonbox["x_range"], y_range=latlonbox["y_range"],
           x_axis_type="mercator", y_axis_type="mercator",
           plot_width=1280, plot_height=800,
           tools="pan,wheel_zoom,box_zoom,reset,zoom_in,zoom_out,save",
           output_backend="webgl")
p.add_tile(CARTODBPOSITRON_RETINA)

p.add_layout(Arrow(end=OpenHead(line_color="#a4225f", size=10, line_width=1),
                   x_start=-9416152.41, y_start=3994480.89, x_end=-9166023.45, y_end=3242606.81))

show(p) 

bokeh version - 1.0.2

Answer 1

You have passed a line_color to OpenHead . If you want to change the color of the arrow shaft, you also need to pass line_color to Arrow as well. They are distinct components, each with their own separate configuration. Same comment applies to line_dash .