How to plot a scatter plot over a map separated by divisions?

Question

I want to plot a scatter plot over a map separated by divisions. So far I have tried the following.

import os
import matplotlib.pyplot as plt
import pandas as pd
import geopandas as gpd
import numpy as np

fPath = 'shape/bgd_adm_bbs_20201113_SHP/bgd_admbnda_adm2_bbs_20201113.shp'
bgd = gpd.read_file(fPath)
ax = bgd.plot(figsize=(15,15),column='ADM1_EN', legend=True)

bgd_admbnda_adm2_bbs_20201113.shp has been found in github. It produces this figure.

Here, there are 8 divisions 'Barishal', 'Chattogram', 'Dhaka', 'Khulna', 'Rajshahi', 'Rangpur', 'Sylhet', 'Mymensingh'. For every division, there are some numeric values(not latitude, longitude values). E.g. for Dhaka division [73.13 77.64 74.32 82.48 84.21 88.23 89.90]. For your convenience, I have attached the files in github. Now, I split the values based on value range. E.g. i) 70-80: [73.13 77.64 74.32], ii) 80-90: [82.48 84.21 88.23 89.90]. Now, I want to draw a scatter plot of two categories of values on any places of Dhaka division with two colors such as this image. I have attached another expected output image for your reference .

Thanks in advance.

user_9441404 · Answer

This is as simple as plotting data on same axis

have data of healthcare facilities, then get GIS data for these facilities
get map GEOJSON and plot on axis
scatter data on same axis, using healthcare facility type as color

import requests, io
import pandas as pd
import geopandas as gpd
import matplotlib.pyplot as plt

# get some data of healthcare facilities
searchendpoint = "https://directory.spineservices.nhs.uk/ORD/2-0-0/organisations"
# get all healthcare facilities in Herefordshire
dfhc = pd.concat([pd.json_normalize(requests
                             .get(searchendpoint, params={"PostCode":f"HR{i}","Status":"Active"})
                             .json()["Organisations"]) 
           for i in range(1,10)]).reset_index(drop=True)

# get geo data for postcodes
dfgeo = (pd.json_normalize(requests.post("http://api.postcodes.io/postcodes", 
               json={"postcodes":dfhc.PostCode.unique().tolist()[0:100]}).json()["result"])
         .rename(columns={"result.postcode":"PostCode","result.longitude":"lng","result.latitude":"lat"})
         .loc[:,["PostCode","lat","lng"]]
        )

dfdata = dfhc.merge(dfgeo, on="PostCode", how="inner")
# going to use as color, so make if categorical so can get codes
dfdata["PrimaryRoleId"] = pd.Categorical(dfdata["PrimaryRoleId"])

fig, ax = plt.subplots(figsize=[14,6])

# get map of regions
df = gpd.read_file(io.StringIO(requests.get("https://martinjc.github.io/UK-GeoJSON/json/eng/msoa_by_lad/topo_E06000019.json").text))
df.plot(ax=ax)
# scatter data on top of region map
ax.scatter(x=dfdata["lng"],y=dfdata["lat"], s=50, c=dfdata["PrimaryRoleId"].cat.codes)

Using same data set

import numpy as np
import geopandas as gpd
import matplotlib.pyplot as plt
import matplotlib

df = gpd.read_file("bgd_admbnda_adm2_bbs_20201113.shp")
fig, ax = plt.subplots(figsize=[8,8])
df.plot(ax=ax, alpha=0.5, edgecolor='k')
# some data that can be plotted on centroid
df["val"] = np.random.randint(1,100,len(df))

# use a discrete 
cmap = plt.cm.get_cmap('jet', 5)
# scatter data based on co-ords of centroid
sc = ax.scatter(x=df.centroid.x, y=df.centroid.y, s=50, c=df["val"], cmap=cmap)
plt.colorbar(sc)

How to plot a scatter plot over a map separated by divisions?

1 Answers

Using same data set