unvec function

Reverse vectorization operator

unvec forms a square matrix from a vector of stacked columns, stacked by vec.

unvec(d, a)

Arguments

• d: the number of rows in the square matrix to be formed.
• a: a size $(d^2x1)$ vector to be unvectorized into a $(dxd)$ matrix.

Returns

a matrix of size $(dxd)$.