I have the following code but when it is run, it gives 0.0
It should return a value of 2 since I am attempting to integrate sin(x) in the interval [0, pi].
Please advise.
from math import sin, pi
def Rsum(a,b):
for i in range(1001):
s = 0
delx = float((b-a)/1000)
g = i*delx
h = (i+1)*delx
y_i = float(sin(a+g))
y_ii = float(sin(a+h))
s += 1/2 * (y_i + y_ii) * delx
return s
print Rsum(0,pi)
1/2 is 0 in python 2.x. It is performing integer division and rounding down. You can get what you want by using 0.5 or 1.0/2 instead.
s = 0 outside the loop.Try this:
from math import sin, pi
def Rsum(a,b):
for i in range(1001):
s = 0.0
delx = float(b-a)/1000.0
g = i*delx
h = (i+1.0)*delx
y_i = float(sin(a+g))
y_ii = float(sin(a+h))
s += 1.0/2.0 * (y_i + y_ii) * delx
#s += 1/2 * (sin(a+i*delx) + sin(a+(i+1)*delx)) * delx
return s
print Rsum(0,pi)
You should be careful about using integer values in floating point equations, if you have an integer, then convert it with float(). If you have a constant in your code like 10 then make it decimal... 10.0.
