问题
I have two vectors, X of bases and N of exponents. I want to get the matrix of all values e = xn for each x in X and n in N.
For example, the following input:
X = [2 3 4]'
N = [1 2 3]
should produce:
ans = [2 4 8; 3 9 27; 4 16 64]
Is there a way to get this without looping (just like you can get all values of x×n by using the column by row product)?
回答1:
Use bsxfun:
bsxfun(@power, X, N)
This assumes that X is a column vector and N is a row vector. If you want to guarantee that, use the following syntax which is more robust:
bsxfun(@power, X(:), N(:).')
回答2:
This is probably a bit sloppier than the bsxfun answer, but you could use meshgrid:
E = X.^(meshgrid(N)')
This assumes both X and N are row vectors. If both are column vectors then it becomes:
E = X.^(meshgrid(N))
来源：https://stackoverflow.com/questions/16881849/vectorized-exponentiation