相关疑难解决方法(0)

假设我想将向量值函数phi应用于向量x:

phi(x, d) = [x.^i for i=0:d]    # vector-valued function
x = rand(7)                     # vector
y = phi(x, 3)                   # should be matrix, but isn't

现在y应该是一个矩阵,但它是4-element Array{Array{Float64,1},1}一个数组,即数组.实际上,我想y成为一个矩阵.执行phi错了吗？或者我该如何转换它？

谢谢!