Merging GeoJSONDataSource and tile providers in a plot

I have a project where I am trying to overlay some Geopandas generated polygons and multiploygons on a Google map tile of Vancouver.

exampleA1712×992 632 KB

exampleB1716×1000 90 KB

I’m using a Colab-hosted Juypter notebook with Python 3.6, Geopandas 0.8.1 and Bokeh 2.1.1. When I check boundaries.to_json()it outputs a JSON feature collection as expected. As one can see, I can plot each set of data individually, but when I try to apply thepatchesto thegmap` figure there is not plot generated. There is no error generated either which has been making it hard to troubleshoot and why I decided to take my problem here.

I seem to be misunderstanding how glyphs are attached to figure, but even looking at some of my old code and searching SO I haven’t been able to combine the data. Does anyone have any suggestions about what I need to change about my code so I can overlay the geojson polygons on the map?

from bokeh.plotting import figure, show, gmap
from bokeh.models import GMapOptions, GeoJSONDataSource
from bokeh.io import output_notebook
from bokeh.palettes import viridis

output_notebook()

boundaries = gpd.read_file(json_file_path)

# Bokeh Graphics
def renderGraphics(gdf_obj):
    # Set up
    map_options = GMapOptions(lat=49.25, lng=-122.65, map_type="roadmap", zoom=8)
    
    # Transform data to Bokeh source
    boundaries = process_dataframe_engine(gdf_obj)
    source = GeoJSONDataSource(geojson = boundaries.to_json())

    plot = gmap(api_key, map_options)
    #plot = figure() development
    plot.title.text = "Metro Vancouver Region"
    plot.plot_height = 500
    plot.plot_width = 860
    plot.toolbar_location = None

    plot.axis.visible = True
    plot.grid.visible = True

    plot.patches(
        "xs",
        "ys",
        fill_color = "color",
        source = source,
        line_color = "black",
        line_width = 1,
        alpha = 0.5
    )

    show(plot)

renderGraphics(boundaries)

Map tile plots use web mercator coordinates, so if your shape coords are lat/lon (as it appears) then you will need to convert them to Mercator.

Going back to the code it appears they are both using Mercator to the best of my knowledge but there are some other things I can try.

If both datasets are using the same Mercator coordinates, are you saying they would merge on render as expected?

I would expect so. If not, we would really need a complete, minimal reproducer to be able to investigate directly.