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.
我有下面的代码,但是当它运行时,它会返回0它会返回一个值2,因为我正在尝试在区间[0,]中对sin(x)积分。请建议。
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)
2 个解决方案
#1
4
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.
1/2在python2。x中是0。它执行整数除法和四舍五入。你可以用0。5或1。1 /2来代替。
#2
0
Try this:
试试这个:
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
.
在浮点数方程中使用整数值时,您应该小心,如果您有一个整数,那么使用float()将其转换为整数值。如果你的代码中有一个常数,比如10,那么把它写成小数…10.0。
#1
4
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.
1/2在python2。x中是0。它执行整数除法和四舍五入。你可以用0。5或1。1 /2来代替。
#2
0
Try this:
试试这个:
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
.
在浮点数方程中使用整数值时,您应该小心,如果您有一个整数,那么使用float()将其转换为整数值。如果你的代码中有一个常数,比如10,那么把它写成小数…10.0。