def drawgreatcircle(self,ax,lon1,lat1,lon2,lat2,dtheta=0.02,color='k', \
linewidth=1.,linestyle='-',dashes=[None,None]):
"""
draw a great circle on the map.
ax - current axis instance.
lon1,lat1 - longitude,latitude of one endpoint of the great circle.
lon2,lat2 - longitude,latitude of the other endpoint of the great circle.
dtheta - interval between points on arc in radians (default=0.02).
color - color to draw great circle (default black).
linewidth - line width for great circle (default 1.)
linestyle - line style for great circle (default '-', i.e. solid).
dashes - dash pattern for great circle (default [None,None], i.e. solid).
Note: cannot handle situations in which the great circle intersects
the edge of the map projection domain, and then re-enters the domain.
"""
gc = GreatCircle(lon1,lat1,lon2,lat2)
if gc.antipodal:
raise ValueError,'cannot draw great circle whose endpoints are antipodal'
# points have spacing of dtheta radians.
npoints = int(gc.distance/dtheta)+1
lons, lats = gc.points(npoints)
x, y = self(lons, lats)
l = Line2D(x,y,linewidth=linewidth,linestyle=linestyle)
l.set_color(color)
if dashes[0] is not None:
l.set_dashes(dashes)
ax.add_line(l)
def drawgreatcircle(self,ax,lon1,lat1,lon2,lat2,dtheta=0.02,color='k', \
linewidth=1.,linestyle='-',dashes=[None,None]):
"""
draw a great circle on the map.
ax - current axis instance.
lon1,lat1 - longitude,latitude of one endpoint of the great circle.
lon2,lat2 - longitude,latitude of the other endpoint of the great circle.
dtheta - interval between points on arc in radians (default=0.02).
color - color to draw great circle (default black).
linewidth - line width for great circle (default 1.)
linestyle - line style for great circle (default '-', i.e. solid).
dashes - dash pattern for great circle (default [None,None], i.e. solid).
Note: cannot handle situations in which the great circle intersects
the edge of the map projection domain, and then re-enters the domain.
"""
gc = GreatCircle(lon1, lat1, lon2, lat2)
if gc.antipodal:
raise ValueError, 'cannot draw great circle whose endpoints are antipodal'
# points have spacing of dtheta radians.
npoints = int(gc.distance / dtheta) + 1
lons, lats = gc.points(npoints)
x, y = self(lons, lats)
l = Line2D(x, y, linewidth=linewidth, linestyle=linestyle)
l.set_color(color)
if dashes[0] is not None:
l.set_dashes(dashes)
ax.add_line(l)
def gcpoints(self,lon1,lat1,lon2,lat2,npoints):
"""
compute npoints points along a great circle with endpoints
(lon1,lat1) and (lon2,lat2). Returns numarrays x,y
with map projection coordinates.
"""
gc = GreatCircle(lon1,lat1,lon2,lat2)
lons, lats = gc.points(npoints)
x, y = self(lons, lats)
return x,y
def gcpoints(self, lon1, lat1, lon2, lat2, npoints):
"""
compute npoints points along a great circle with endpoints
(lon1,lat1) and (lon2,lat2). Returns numarrays x,y
with map projection coordinates.
"""
gc = GreatCircle(lon1, lat1, lon2, lat2)
lons, lats = gc.points(npoints)
x, y = self(lons, lats)
return x, y
def angle(p1, p2, radians=False):
"""Calculate the angle in degrees between points *p1* and *p2*.
If *radians* is False, *p1* and *p2* are assumed to be in degrees, and
the returned angle will be in degrees. Otherwise, radians are assumed, and
returned.
"""
import numpy as np
if radians:
factor = 1.
else:
factor = _d2r
lon1, lat1 = np.array(p1) * factor
lon2, lat2 = np.array(p2) * factor
from math import acos, sin, cos
# From http://en.wikipedia.org/wiki/Great-circle_distance
return acos(
sin(lon1) * sin(lon2) +
cos(lon1) * cos(lon2) * cos(lat1 - lat2)) / factor
# WGS84
a = 6378137.0
b = 6356752.3142
from greatcircle import GreatCircle
circle = GreatCircle(a, b, lon1, lat1, lon2, lat2)
return circle.distance
def drawgreatcircle(self,lon1,lat1,lon2,lat2,dtheta=0.02,**kwargs):
"""
draw a great circle on the map.
lon1,lat1 - longitude,latitude of one endpoint of the great circle.
lon2,lat2 - longitude,latitude of the other endpoint of the great circle.
dtheta - points on great circle computed every dtheta radians (default 0.02).
Other keyword arguments (**kwargs) control plotting of great circle line,
see pylab plot documentation for details.
Note: cannot handle situations in which the great circle intersects
the edge of the map projection domain, and then re-enters the domain.
"""
# get current axes instance.
ax = pylab.gca()
gc = GreatCircle(lon1,lat1,lon2,lat2)
if gc.antipodal:
raise ValueError,'cannot draw great circle whose endpoints are antipodal'
# points have spacing of dtheta radians.
npoints = int(gc.distance/dtheta)+1
lons, lats = gc.points(npoints)
x, y = self(lons, lats)
self.plot(x,y,**kwargs)
def drawgreatcircle(self,lon1,lat1,lon2,lat2,dtheta=0.02,**kwargs):
"""
draw a great circle on the map.
lon1,lat1 - longitude,latitude of one endpoint of the great circle.
lon2,lat2 - longitude,latitude of the other endpoint of the great circle.
dtheta - increment in radians to compute points for drawing great circle
(default 0.02).
Other keyword arguments control plotting of great circle line - see
pylab plot documentation.
Note: cannot handle situations in which the great circle intersects
the edge of the map projection domain, and then re-enters the domain.
"""
# get current axes instance.
ax = pylab.gca()
gc = GreatCircle(lon1,lat1,lon2,lat2)
if gc.antipodal:
raise ValueError,'cannot draw great circle whose endpoints are antipodal'
# points have spacing of dtheta radians.
npoints = int(gc.distance/dtheta)+1
lons, lats = gc.points(npoints)
x, y = self(lons, lats)
self.plot(x,y,**kwargs)
