4H2012 rsum2graph.py

#!/usr/bin/python
from matplotlib import *
from pylab import *

a=-pi/2
b=pi/2
n=1000
def f(x):
    return sin(x)

h=1.0*(b-a)/n
x=[a+(i+1)*h for i in range(n)]
y=[f(a+(i+1)*h) for i in range(n)]
areas=[f(a+(i+1)*h)*h for i in range(n)]
area=sum(areas)

print "x=",x
print "y=",y
print "areas=",areas
print "area=",area

plot(x,y,color='red')

for i in range(n):
    matplotlib.pyplot.gca().add_patch(matplotlib.patches.Rectangle((a+i*h,0),h,f(a+(i+1)*h)))

show()