Cartopy plotting unwanted lines on map

Question

I'm very (very very) new at this game of mapping/carto in Python, and am finding a drought of resources available for CartoPy, so I thought someone here may be able to help.

I have thousands of lat/long coordinates to plot, distributed across 4 parallel lines.

My code so far is:

import pandas as pd
import numpy as np
import os    

import matplotlib.pyplot as plt
import cartopy.crs as ccrs       
from cartopy import config         
import cartopy.feature as cf        

latcol = [2]
loncol = [3]
df_lat = pd.read_csv(r'G:\Documents\Thesis\Outputs\concat_Xenos_combineds.csv', usecols = latcol)
df_lon = pd.read_csv(r'G:\Documents\Thesis\Outputs\concat_Xenos_combineds.csv', usecols = loncol)

map = plt.figure(figsize=(15,15))
ax = plt.axes(projection=ccrs.EuroPP())
ax.coastlines(resolution='10m')

ax.add_feature(cf.LAND)
ax.add_feature(cf.OCEAN)
ax.add_feature(cf.COASTLINE)
ax.add_feature(cf.BORDERS, linestyle=':')
ax.add_feature(cf.LAKES, alpha=0.5)
ax.add_feature(cf.RIVERS)

ax.plot(df_lon, df_lat, markersize=2, marker='o', color='red', transform=ccrs.PlateCarree())

ax.stock_img()

As I said, the coordinates are distributed accross 4 parallel lines. but the plot produced is messy as anything with lines going all over the place:

How do I correct this pls?

Also, I have a third column with a numerical value representing the value_count of a specific feature type at each coordinate point, and would eventually like to incorperate this into the map some way (whether as different sized or coloured markers or different colours). whats the best way to achieve this? Is it worth trying to do a heatmap-style plot instead/

Any clarification needed don't hesitate to ask!

Thanks, R

Answer 1

To get rid of red lines between the markers, pass linestyle='none' to plot() .

Regarding your second question, you should probably use ax.scatter() and use the value_count variable for color.