scipy求二重(多重)积分:点击跳转.
sympy求积分:点击跳转.
问题1:求解如下一重积分:
F
(
x
)
=
∫
0
1
x
2
+
e
x
+
1
d
x
.
F(x) = \int_0^1 x^{2}+e^{x}+1 ~dx\,.
F(x)=∫01x2+ex+1 dx.
程序1.
import scipy.integrate as integrate
import numpy as np
result = integrate.quad(lambda x: x**2 + np.exp(x) + 1, 0, 1)
print(result)
程序2.
import scipy.integrate as integrate
import numpy as np
def f(x):
return x**2 + np.exp(x) + 1
result = integrate.quad(f, 0, 1)
print(result)
结果:
(3.051615161792378, 3.3879734149171206e-14)
问题2:假设求解如下积分:
F
(
x
)
=
∫
0
1
a
x
2
+
b
x
+
c
d
x
.
F(x) = \int_0^1 ax^{2}+bx + c~dx\,.
F(x)=∫01ax2+bx+c dx.
假设:
a
=
3
,
b
=
2
,
c
=
1
a=3, ~b=2, ~c=1
a=3, b=2, c=1
即: F ( x ) = ∫ 0 1 3 x 2 + 2 x + 1 d x . F(x) = \int_0^1 3x^{2}+2x + 1~dx\,. F(x)=∫013x2+2x+1 dx.
程序:
from scipy.integrate import quad
def integrand(x, a, b, c):
return a*x**2 + b*x + c
a = 3
b = 2
c = 1
I = quad(integrand, 0, 1, args=(a,b,c))
print(I)
结果:
(3.0, 3.3306690738754696e-14)