On 6/29/10 1:19 PM, Thomas Lecocq wrote:
Hi,
 
What about ordering the arrays before plotting ? Are the first elements drawn back to front ?
 
Thomas

**********************
Thomas Lecocq
Geologist
Ph.D.Student (Seismology)
Royal Observatory of Belgium
**********************


 

Date: Mon, 28 Jun 2010 12:55:22 -0400
From: athakral@weatherinnovations.com
To: matplotlib-users@lists.sourceforge.net
Subject: [Matplotlib-users] zorder for individual points in a scatter plot on a Basemap

Hi,

I'm currently using a scatter plot on a Basemap and I'd like to set the zorder of the individual points based on their temperature.   The higher the temperature, the higher the zorder.  Also, i'm  using a colorbar to set the colors for the plot.  Here is a snippet of my code:

        x = np.array(val)
        fig.sca(ax1)
        lon_0 =(urcrnrlon+llcrnrlon)/2
        lat_0 =
(urcrnrlat+llcrnrlat)/2
        m =     Basemap(llcrnrlon=llcrnrlon,llcrnrlat=llcrnrlat,urcrnrlon=urcrnrlon,
                urcrnrlat=urcrnrlat,resolution='i',projection='cyl',lon_0=lon_0,lat_0=lat_0)
        m.drawcoastlines()
        m.drawmapboundary()
        m.drawparallels(np.arange(llcrnrlat-1,urcrnrlat+1,5.))
        m.drawmeridians(np.arange(llcrnrlon-1,urcrnrlon+1,5.))
        m.fillcontinents(color='white',lake_color='aqua')
        m.drawcountries(linewidth=1)
        lons,lats = m(lon,lat)
       
        #I can do it this way, but this screws up the colorbar
        #for i in range(len(x)):
        #    m.scatter(lons[i],lats[i],c=x[i],marker='o',picker=5,zorder=x[i])   
 
        m.scatter(lons,lats,c=x,marker='o',picker=5)   
        plt.title('Time Range: %s to %s'%(startDay.strftime("%b-%d %H:%M"),endDay.strftime("%b-%d %H:%M")))
        plt.colorbar(shrink=0.5)

Is there anyway to set the zorder of the points without using the loop in commented code? Any help would be greatly appreciated.

Thanks,


Aman:  You can save the mappable from the scatter you want the colorbar to represent, then pass that to colorbar.  i.e.

im = m.scatter(lons,lats,c=x,marker='o',picker=5) # plot all the pts, save mappable 

# now do one at a time
for i in range(len(x)):
    m.scatter(lons[i],lats[i],c=x[i],marker='o',picker=5,zorder=x[i]) 
plt.colorbar(im,shrink=0.5) # use mappable from 1st call to scatter for colorbar

-Jeff
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