# Convert math equations to numpy

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This is a memo for coding matrix operations in numpy.

A*B


## Matrix multiplication

np.dot(A, B)
np.matmul(A, B)
A @ B


## Outer product

np.outer(A, B)


## Kronecker product

np.kron(A, B)


if a and b are vectors, the Kronecker product is a form of vectorization (or flattening) of the outer product of a and b.

np.kron(a, b) == np.outer(a, b).reshape(-1)