vec2sym

hypercoil.functional.matrix.vec2sym(vec: Tensor, offset: int = 1) → Tensor

Convert a block of ravelled vectors into symmetric matrices.

The ordering of the input vectors should follow the upper triangle of the matrices to be formed.

Parameters:

vectensor

Block of vectors to convert. Input vectors should be of length (n choose 2), where n is the number of elements on the offset diagonal, plus 1.

offsetint (default 1)

Offset from the main diagonal where the upper triangle begins. By default, the main diagonal is not included. Set this to 0 to place elements along the main diagonal.

Returns:

symtensor

Block of symmetric matrices formed by first populating the offset upper triangle with the elements from the input vec, then symmetrising.