Как ограничить количество вызовов функций в scipy.integrate.quad? ⇐ Python

[Anonymous]

Похоже, что Scipy.integrate.quad() в некоторых случаях выполняет слишком много вызовов функций. Вот простой тест для демонстрации:

Код: Выделить всё

import numpy as np
from scipy import integrate

def intgnd(x):
p = x + x**2
return p

x0=-1
x1=1
epsrel=0.1
epsabs=0.1
I,err,info = integrate.quad(intgnd,x0,x1,full_output=1,epsabs=epsabs,epsrel=epsrel)
print("{:.3f}, {:.3g}, {}, {}".format(I,err,info['neval'],info['last']))

The function to integrate is a second-degree polynomial, and can be integrated exactly by two-point Gaussian quadrature. quad() gets the right answer, but uses 21 points to do it. Here's the output:

Код: Выделить всё

0.667, 1.11e-14, 21, 1

Furthermore I only asked for an absolute error of 0.1, so I didn't even need an exact result. I have found no way to force quad() to use anything less than 21 function calls, regardless of the values of epsabs, epsrel or limit. How can I get quad() to use fewer function calls?


Источник: https://stackoverflow.com/questions/675 ... grate-quad