Re: [Matplotlib-users] matplotlib/basemap plot geo data on background map

[Aman T. <ama...@gm...>]

If you're just looking for points, you can use ax.scatter().  It will plot
the points.  Also, make sure you set the zorder keyword argument in the
scatter.

Example:
x=range(10)
y=range(10)
z=range(10,20)
ax.scatter(x,y,c=z,zorder=10)

Hope this helps,
Aman

On Fri, Sep 10, 2010 at 1:06 PM, izzybitsie <is...@ju...> wrote:

>
> Hi,
> I'm new to matplotlib and I'm looking for an easy way to plot geographical
> data on a background map: bkgmap.png
> http://old.nabble.com/file/p29679002/bkgmap.png
> So far I only found out about warpimage() to do this but only part of
> bkgmap.png comes up in the output image.  I think this is because this
> image
> has no pixels covering all the world.
> http://old.nabble.com/file/p29679002/partialbkg_polygon.png
>
> Any idea on how to insert this image as background?
> THANKS
>
> Code: the polygon displays in right position even though background doesn't
> show OK (tested with map,lat/lon lines drawn too)
>
> import sys
> import Image, ImageDraw  # PIL
> from matplotlib.patches import Polygon
> from mpl_toolkits.basemap import Basemap
> import matplotlib.image as mpimg
> import matplotlib.pyplot as plt
> import numpy as np
>
> lat0=48
> lon0=13
> lllon=-15
> lllat=20
> urlon=73
> urlat=57
> map =
>
> Basemap(projection='stere',lat_0=lat0,lon_0=lon0,llcrnrlon=lllon,llcrnrlat=lllat,urcrnrlon=urlon,urcrnrlat=urlat,
>              resolution='c',area_thresh=1000.)
> map.warpimage(image='bkgmap.png',scale=None,ax=plt.gca())
> # points
> lat = [50.,55.,45.,40.,50.]
> lon = [-20.,-10.,10.,-10.,-20.]
> x0,y0 = map(lon[0],lat[0])
> x1,y1 = map(lon[1],lat[1])
> x2,y2 = map(lon[2],lat[2])
> x3,y3 = map(lon[3],lat[3])
> x4,y4 = map(lon[4],lat[4])
>
> plt.gca().add_patch(Polygon([(x0,y0),(x1,y1),(x2,y2),(x3,y3),(x4,y4)],fill=1,facecolor='red',edgecolor='black'))
> plt.show()
> --
> View this message in context:
> http://old.nabble.com/matplotlib-basemap-plot-geo-data-on-background-map-tp29679002p29679002.html
> Sent from the matplotlib - users mailing list archive at Nabble.com.
>
>
>
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-- 
Aman Thakral
B.Eng & Biosci, M.Eng Design