R Graphical Manual

Last data update: 2014.03.03

R: Creates a "diagonal" tensor

diag.tensor

R Documentation

Creates a "diagonal" tensor

The diagonal tensor is the tensor equivalent of the diagonal matrix.

diag.tensor(X,mark="'",dn=NULL,by=NULL)

`X`	a tensor containing the diagonal entries.
`mark`	a character to be concatenated to the names of the row dimensions to get the column dimension names
`dn`	dimnames which are used twice
`by`	The diagonal tensor is created for each level of the indices in `by`.

E_{i_1...i_n j_1...j_n}=δ_{i_1j_1}...δ_{i_n j_n}

a tensor with dimension c(dim(X),mark(dim(X),mark))

K. Gerald van den Boogaart

A <- to.tensor(1:4,c(a=2,b=2))
diag.tensor(A)
diag.tensor(A,by="b")