同问，可是怎么没人理呢

monte carlo? 或者别的数值积分法应该也很多吧。。。。。

cubature包 adaptIntegrate函数
看帮助找具体用法吧。

恩，好东西，先收藏了。
I.2d <- function(x) {
  x1 = x[1]
  x2 = x[2]
  sin(4*x1+1) * cos(4*x2) * x1 * (x1*(x1*x1)^2 - x2*(x2*x2 - x1) +2)
}

adaptIntegrate(I.2d, rep(-1, 2), rep(1, 2), maxEval=10000)

UsageadaptIntegrate(f, lowerLimit, upperLimit, tol = 1e-05, fDim = 1, maxEval = 0, absError=0)Arguments

f	The function (integrand) to be integrated
lowerLimit	The lower limit of integration, a vector for hypercubes
upperLimit	The upper limit of integration, a vector for hypercubes
tol	The maximum tolerance, default 1e-5.
fDim	The dimension of the integrand, default 1, bears no relation to the dimension of the hypercube
maxEval	The maximum number of function evaluations needed, default 0 implying no limit
absError	The maximum absolute error tolerated

太牛了，崇拜啊