Plot trajectories on an map using matplotlib-basemap

Paul Hobson

2013-01-29 17:53:38 UTC

On Mon, Jan 28, 2013 at 9:41 PM, Boris Vladimir Comi <

Post by Boris Vladimir Comi
#! /usr/bin/python
import numpy as np
data =
np.loadtxt('path-tracks.csv',dtype=np.str,delimiter=',',skiprows=1)
print data
[['19.70' '-95.20' '2/5/04 6:45 AM' '1' '-38' 'CCM']
['19.70' '-94.70' '2/5/04 7:45 AM' '1' '-48' 'CCM']
['19.30' '-93.90' '2/5/04 8:45 AM' '1' '-60' 'CCM']
['19.00' '-93.50' '2/5/04 9:45 AM' '1' '-58' 'CCM']
['19.00' '-92.80' '2/5/04 10:45 AM' '1' '-50' 'CCM']
['19.20' '-92.60' '2/5/04 11:45 AM' '1' '-40' 'CCM']
['19.90' '-93.00' '2/5/04 12:45 PM' '1' '-43' 'CCM']
['20.00' '-92.80' '2/5/04 1:15 PM' '1' '-32' 'CCM']
['23.10' '-100.20' '30/5/04 4:45 AM' '2' '-45' 'SCME']
['23.20' '-100.00' '30/5/04 5:45 AM' '2' '-56' 'SCME']
['23.30' '-100.00' '30/5/04 6:45 AM' '2' '-48' 'SCME']
['23.30' '-100.20' '30/5/04 7:45 AM' '2' '-32' 'SCME']
['23.40' '-99.00' '31/5/04 3:15 AM' '3' '-36' 'SCM']
['23.50' '-98.90' '31/5/04 4:15 AM' '3' '-46' 'SCM']
['23.60' '-98.70' '31/5/04 5:15 AM' '3' '-68' 'SCM']
['23.70' '-98.80' '31/5/04 6:15 AM' '3' '-30' 'SCM']]
with the above code I get an array whose columns represent: [Lat, Lon,
Date, Identifier, Temperatures, Category]. Now, I will put a code that
#!/usr/bin/python
#Project Storm: Plot trajectories of convective systems
#import libraries
import numpy as np
from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as pl
# Plot a map for Mexico
m = Basemap(projection='cyl', llcrnrlat=12,
urcrnrlat=35,llcrnrlon=-120, urcrnrlon=-80, resolution='c',
area_thresh=1000.)
m.bluemarble()
m.drawcoastlines(linewidth=0.5)
m.drawcountries(linewidth=0.5)
m.drawstates(linewidth=0.5)
#Draw parallels and meridians
m.drawparallels(np.arange(10.,35.,5.))
m.drawmeridians(np.arange(-120.,-80.,10.))
m.drawmapboundary(fill_color='aqua')
#Open file whit numpy
data = np.loadtxt('path-tracks.csv', dtype=np.str,delimiter=' , ', skiprows=1)
latitude = data[:,0]
longitude = data[:,1]
#Convert latitude and longitude to coordinates X and Y
x, y = m(longitude, latitude)
#Plot the points on the map
pl.plot(x,y,'ro-')
pl.show()
The points plotted on the map, corresponding to three different paths with a
line connecting all points. Mi final idea is to draw a line connecting
the points associated with each path, How I can do this? or How should I
structure my data to plot the different paths?
is posible draw an identifier or a mark for each path?
how I can set the size of the figure so that it can distinguish the
separation between the points?

Boris,

I don't have the time to look into this in great detail. However, in
general, you can get your current axes and figure objects with the
following:

ax = pl.gca()
fig = pl.gcf()

Then you can use the 'annotate' method of 'ax' to call out each path. (See
matplotlib,org/examples for help with its use). And then use:

fig.set_figwidth(7) # example
fig.set_figheight(7) # example

...to make the figure bigger. Finally, use

fig.tight_layout()

to fill up the newly enlarged figure.

Hope that helps,
-paul