CODEWITHSUNDEEP
pythonarraysdictionarymatplotlibplot
urgeo
urgeo

Reputation: 641

overplot array on a world map in python

I want to plot a 2D array 3298x9896 named IR over a world map, that is the world planisphere (you can see Africa on the left):

enter image description here

Now I need to overplot a filling in world map grid. I usually make use of map to create a projected world grid with continents and it works fine:

fig = plt.figure(figsize=(18,9))
map = Basemap(projection='cyl', lat_0 = 57, lon_0 = -135, resolution = 'c', area_thresh = 0.1, llcrnrlon=0.0, llcrnrlat=-60.0, urcrnrlon=360.0, urcrnrlat=60.0)
map.drawcoastlines()
map.drawcountries()
map.drawparallels(np.arange(-90,90,15.0),labels=[1,1,0,1])
map.drawmeridians(np.arange(-180,180,15),labels=[1,1,0,1])
map.drawmapboundary()

But if now I try to overplot the array data:

fig = plt.imshow(IR)

enter image description here

I get the attached picture, that seems incomplete and doesn't fill in the map. Now, except for the colors, what am I doing wrong? Thanks in advance.

Upvotes: 1

Views: 1682

Answers (1)

Chiel
Chiel

Reputation: 6194

You should use the Basemap instance map for imshow:

fig = map.imshow(IR)

to make sure the projection is used. The example below uses random data, but works correctly

from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure(figsize=(18,9))
map = Basemap(projection='cyl', lat_0 = 57, lon_0 = -135, resolution = 'c', area_thresh = 0.1, llcrnrlon=0.0, llcrnrlat=-60.0, urcrnrlon=360.0, urcrnrlat=60.0)
map.drawcoastlines()
map.drawcountries()
map.drawparallels(np.arange(-90,90,15.0),labels=[1,1,0,1])
map.drawmeridians(np.arange(-180,180,15),labels=[1,1,0,1])
map.drawmapboundary()

IR = np.random.rand(3298, 9896)

map.imshow(IR)

Upvotes: 1

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