matvec-methods {rTensor}

Tensor Matvec Unfolding

Description

For 3-tensors only. Stacks the slices along the third mode. This is the prevalent unfolding for T-SVD and T-MULT based on block circulant matrices.

Usage

matvec(tnsr)

## S4 method for signature 'Tensor'
matvec(tnsr)

Arguments

tnsr

the Tensor instance

Details

matvec(tnsr)

Value

matrix with prod(x@modes[-m]) rows and x@modes[m] columns

References

M. Kilmer, K. Braman, N. Hao, and R. Hoover, "Third-order tensors as operators on matrices: a theoretical and computational framework with applications in imaging". SIAM Journal on Matrix Analysis and Applications 2013.

See Also

k_unfold-methods and unfold-methods

Examples

tnsr <- rand_tensor(c(2,3,4))
matT1<- matvec(tnsr)