Revision: 5326 http://matplotlib.svn.sourceforge.net/matplotlib/?rev=5326&view=rev Author: jdh2358 Date: 2008年05月30日 10:30:59 -0700 (2008年5月30日) Log Message: ----------- added ellipse demo Added Paths: ----------- trunk/htdocs/screenshots/ellipse_large.py Added: trunk/htdocs/screenshots/ellipse_large.py =================================================================== --- trunk/htdocs/screenshots/ellipse_large.py (rev 0) +++ trunk/htdocs/screenshots/ellipse_large.py 2008年05月30日 17:30:59 UTC (rev 5326) @@ -0,0 +1,149 @@ + +# This example can be boiled down to a more simplistic example +# to show the problem, but bu including the upper and lower +# bound ellipses, it demonstrates how significant this error +# is to our plots. + +import math +from pylab import * +from matplotlib.patches import Ellipse, Arc + +# given a point x, y +x = 2692.440 +y = 6720.850 + +# get is the radius of a circle through this point +r = math.sqrt( x*x+y*y ) + +# show some comparative circles +delta = 6 + + +################################################## +def custom_ellipse( ax, x, y, major, minor, theta, numpoints = 750, **kwargs ): + xs = [] + ys = [] + incr = 2.0*math.pi / numpoints + incrTheta = 0.0 + while incrTheta <= (2.0*math.pi): + a = major * math.cos( incrTheta ) + b = minor * math.sin( incrTheta ) + l = math.sqrt( ( a**2 ) + ( b**2 ) ) + phi = math.atan2( b, a ) + incrTheta += incr + + xs.append( x + ( l * math.cos( theta + phi ) ) ) + ys.append( y + ( l * math.sin( theta + phi ) ) ) + # end while + + incrTheta = 2.0*math.pi + a = major * math.cos( incrTheta ) + b = minor * math.sin( incrTheta ) + l = sqrt( ( a**2 ) + ( b**2 ) ) + phi = math.atan2( b, a ) + xs.append( x + ( l * math.cos( theta + phi ) ) ) + ys.append( y + ( l * math.sin( theta + phi ) ) ) + + ellipseLine = ax.plot( xs, ys, **kwargs ) + + + + +################################################## +# make the axes +ax1 = subplot( 311, aspect='equal' ) +ax1.set_aspect( 'equal', 'datalim' ) + +# make the lower-bound ellipse +diam = (r - delta) * 2.0 +lower_ellipse = Ellipse( (0.0, 0.0), diam, diam, 0.0, fill=False, edgecolor="darkgreen" ) +ax1.add_patch( lower_ellipse ) + +# make the target ellipse +diam = r * 2.0 +target_ellipse = Ellipse( (0.0, 0.0), diam, diam, 0.0, fill=False, edgecolor="darkred" ) +ax1.add_patch( target_ellipse ) + +# make the upper-bound ellipse +diam = (r + delta) * 2.0 +upper_ellipse = Ellipse( (0.0, 0.0), diam, diam, 0.0, fill=False, edgecolor="darkblue" ) +ax1.add_patch( upper_ellipse ) + +# make the target +diam = delta * 2.0 +target = Ellipse( (x, y), diam, diam, 0.0, fill=False, edgecolor="#DD1208" ) +ax1.add_patch( target ) + +# give it a big marker +ax1.plot( [x], [y], marker='x', linestyle='None', mfc='red', mec='red', markersize=10 ) + +################################################## +# make the axes +ax = subplot( 312, aspect='equal' , sharex=ax1, sharey=ax1) +ax.set_aspect( 'equal', 'datalim' ) + +# make the lower-bound arc +diam = (r - delta) * 2.0 +lower_arc = Arc( (0.0, 0.0), diam, diam, 0.0, fill=False, edgecolor="darkgreen" ) +ax.add_patch( lower_arc ) + +# make the target arc +diam = r * 2.0 +target_arc = Arc( (0.0, 0.0), diam, diam, 0.0, fill=False, edgecolor="darkred" ) +ax.add_patch( target_arc ) + +# make the upper-bound arc +diam = (r + delta) * 2.0 +upper_arc = Arc( (0.0, 0.0), diam, diam, 0.0, fill=False, edgecolor="darkblue" ) +ax.add_patch( upper_arc ) + +# make the target +diam = delta * 2.0 +target = Arc( (x, y), diam, diam, 0.0, fill=False, edgecolor="#DD1208" ) +ax.add_patch( target ) + +# give it a big marker +ax.plot( [x], [y], marker='x', linestyle='None', mfc='red', mec='red', markersize=10 ) + + + + + +################################################## +# now lets do the same thing again using a custom ellipse function + + + +# make the axes +ax = subplot( 313, aspect='equal', sharex=ax1, sharey=ax1 ) +ax.set_aspect( 'equal', 'datalim' ) + +# make the lower-bound ellipse +custom_ellipse( ax, 0.0, 0.0, r-delta, r-delta, 0.0, color="darkgreen" ) + +# make the target ellipse +custom_ellipse( ax, 0.0, 0.0, r, r, 0.0, color="darkred" ) + +# make the upper-bound ellipse +custom_ellipse( ax, 0.0, 0.0, r+delta, r+delta, 0.0, color="darkblue" ) + +# make the target +custom_ellipse( ax, x, y, delta, delta, 0.0, color="#BB1208" ) + +# give it a big marker +ax.plot( [x], [y], marker='x', linestyle='None', mfc='red', mec='red', markersize=10 ) + + +# give it a big marker +ax.plot( [x], [y], marker='x', linestyle='None', mfc='red', mec='red', markersize=10 ) + +################################################## +# lets zoom in to see the area of interest + +ax1.set_xlim(2650, 2735) +ax1.set_ylim(6705, 6735) + +savefig("ellipse") +show() + + This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site.