返回R语言calculus包函数列表

计算函数、表达式和字符的hessian矩阵。

hessian(f, var, accuracy = 2, stepsize = NULL, coordinates = "cartesian")

f %hessian% var

f : 函数、表达式或字符。

var : 字符向量，给出要计算导数的变量名。如果提供了命名向量，则将在该点计算导数。

accuracy : 数值导数的准确度。

stepsize : 数值导数的有限差分步长。默认情况下自动优化。

coordinates : 要使用的坐标系。其中之一：笛卡尔、极坐标、球面、圆柱、抛物线、抛物线圆柱或每个变量的比例因子的特征向量。

# hessian with respect to xhessian(f = "sin(x)", var = "x")"sin(x)" %hessian% "x"

# hessian with respect to x and evaluate in x = 0hessian(f = "sin(x)", var = c("x" = 0))"sin(x)" %hessian% c(x=0)

# hessian with respect to (x,y)hessian(f = "y*sin(x)", var = c("x","y"))"y*sin(x)" %hessian% c("x","y")

# hessian in spherical coordinateshessian('r*theta*phi', var = c('r','theta','phi'), coordinates = 'spherical')

# numerical hessian in spherical coordinatesf < - function(r, theta, phi) r*theta*phihessian(f, var = c('r'=1, 'theta'=pi/4, 'phi'=pi/4), coordinates = 'spherical')