The following Python script draws an ellipse.
from numpy import linspace
from scipy import pi,sin,cos
def ellipse(ra,rb,ang,x0,y0,Nb=50):
'''ra - major axis length
rb - minor axis length
ang - angle
x0,y0 - position of centre of ellipse
Nb - No. of points that make an ellipse
based on matlab code ellipse.m written by D.G. Long,
Brigham Young University, based on the
CIRCLES.m original
written by Peter Blattner, Institute of Microtechnology,
University of
Neuchatel, Switzerland, blattner@imt.unine.ch
'''
xpos,ypos=x0,y0
radm,radn=ra,rb
an=ang
co,si=cos(an),sin(an)
the=linspace(0,2*pi,Nb)
X=radm*cos(the)*co-si*radn*sin(the)+xpos
Y=radm*cos(the)*si+co*radn*sin(the)+ypos
return X,Y
def test():
import pylab as p
fig = p.figure(figsize=(5,5))
p.axis([-3,3,-3,3])
#eg 1
X,Y=ellipse(2,1,pi*2.0/3.0,0,1)
p.plot(X,Y,"b.-",ms=1) # blue ellipse
#eg 2
X,Y=ellipse(2,0.2,pi/3.0,1,1)
p.plot(X,Y,"r.-",ms=1) # red ellipse
#eg 3
X,Y=ellipse(1,1,pi/3.0,-1,1,Nb=16)
p.plot(X,Y,"g.-",ms=1) # green ellipse
p.grid(True)
p.show()
if __name__ == '__main__':
test()
Note
The script is in
ellipse.py.
