Re: [Matplotlib-users] Plot trajectories on an map using matplotlib-basemap

[Paul H. <pmh...@gm...>]

On Mon, Jan 28, 2013 at 9:41 PM, Boris Vladimir Comi <
gl...@co...> wrote:

>
>   #! /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
> allows me to plot the first and second column on the map of Mexico:
>
>
>
>     #!/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