matplotlib-users Mailing List for matplotlib

Dear Jeffrey & ALL,

Are there any way to plot a Basemap using a standard Equidistant
Cylindrical Projection, but centered on the Pacific Basin instead of
the default plot? This can be done easily with all projections that
require just a center point at lat_0, long_0 (Robinson, Mollweide,
Orthographic, Geostationary) but could not figure out how to do this
in projections that require a bounding rectangle to be defined (as is
the case with the Equidistant Cylindrical).

Thanks in advance!

With best regards,

-- 
Dr. Mauro J. Cavalcanti
Ecoinformatics Studio
P.O. Box 46521, CEP 20551-970
Rio de Janeiro, RJ, BRASIL
E-mail: mau...@gm...
Web: http://studio.infobio.net
Linux Registered User #473524 * Ubuntu User #22717
"Life is complex. It consists of real and imaginary parts."

Dear Jeffrey,

2008/12/6 Jeff Whitaker <js...@fa...>:

> Mauro:  There never actually was a Basemap 0.90 - could you check that
> version number again with

Sorry, my reference to a "0.90" version was a typo! Indeed, I have version 0.99

Thanks for the information on the drawing of rivers; I will see how I
can provide this feature to users, warning them that the first plot
may take some time to complete.

BTW, even if there are reasons for the slowness of river plotting and
Blue Marble superimposition, have you any information on the most
appropriate hardware requirements for getting the fastest plots in
these cases?

As of volunteers for helping with the Basemap documentation, count me
in, just after I have my current project finished (hopefully by the
next month). One idea I have is creating a "Basemap Cookbook" website,
essentially presenting all the examples included in the current
distribution, plus a few others (as the additional example for
plotting shapefiles that you posted on the list a few days ago).

With warmest regards,

-- 
Dr. Mauro J. Cavalcanti
Ecoinformatics Studio
P.O. Box 46521, CEP 20551-970
Rio de Janeiro, RJ, BRASIL
E-mail: mau...@gm...
Web: http://studio.infobio.net
Linux Registered User #473524 * Ubuntu User #22717
"Life is complex. It consists of real and imaginary parts."

"""
Show how to use a lasso to select a set of points and get the indices
of the selected points.  A callback is used to change the color of the
selected points

This is currently a proof-of-concept implementation (though it is
usable as is).  There will be some refinement of the API and the
inside polygon detection routine.
"""
from matplotlib.widgets import Lasso
import matplotlib.mlab
from matplotlib.nxutils import points_inside_poly
from matplotlib.colors import colorConverter
from matplotlib.collections import RegularPolyCollection

from matplotlib.pyplot import figure, show
from numpy import nonzero
from numpy.random import rand

class Datum:
    colorin = colorConverter.to_rgba('red')
    colorout = colorConverter.to_rgba('green')
    def __init__(self, x, y, include=False):
        self.x = x
        self.y = y
        if include: self.color = self.colorin
        else: self.color = self.colorout


class LassoManager:
    def __init__(self, ax, data):
        self.axes = ax
        self.canvas = ax.figure.canvas
        self.data = data
        #the lasso lock boolean is used to tell whether another
        #widget event has priority
        self.lassoLock = False

        self.Nxy = len(data)

        facecolors = [d.color for d in data]
        self.xys = [(d.x, d.y) for d in data]
        fig = ax.figure
        self.collection = RegularPolyCollection(
            fig.dpi, 6, sizes=(100,),
            facecolors=facecolors,
            offsets = self.xys,
            transOffset = ax.transData)

        ax.add_collection(self.collection)

        self.cid = self.canvas.mpl_connect('button_press_event', self.onpress)
        self.cidRelease = self.canvas.mpl_connect('button_release_event', self.onrelease)

        self.ind = None

    def callback(self, verts):
        facecolors = self.collection.get_facecolors()
        ind = nonzero(points_inside_poly(self.xys, verts))[0]
        for i in range(self.Nxy):
            if i in ind:
                facecolors[i] = Datum.colorin
            else:
                facecolors[i] = Datum.colorout

        self.canvas.draw_idle()
        self.canvas.widgetlock.release(self.lasso)
        #del self.lasso
        self.ind = ind

    def onpress(self, event):
        if self.canvas.widgetlock.locked(): return
        if event.inaxes is None: return
        self.lasso = Lasso(event.inaxes, (event.xdata, event.ydata), self.callback)
        # acquire a lock on the widget drawing
        self.canvas.widgetlock(self.lasso)
        # establish boolean that can be used to release the widgetlock
        self.lassoLock = True

    def onrelease(self, event):
        'on release we reset the press data'
        # test whether the widgetlock was initiated by the lasso
        if self.lassoLock:
            self.canvas.widgetlock.release(self.lasso)
            self.lassoLock = False
        print self.ind


if __name__ == '__main__':

    data = [Datum(*xy) for xy in rand(100, 2)]

    fig = figure()
    ax = fig.add_subplot(111, xlim=(0,1), ylim=(0,1), autoscale_on=False)
    lman = LassoManager(ax, data)

    show()