delta.tensor: Creates a Kronecker delta tensor
Description
The delta tensor is the tensor equivalent of the identity.
Usage
delta.tensor(d,mark="'",dn=NULL,by=NULL)
Value
a tensor with dimension c(d,mark(d,mark))
Arguments
- d
the row dimensions
- mark
a character to be concatenated to the names of the row
dimensions to get the column dimension names
- dn
dimnames for the result
- by
the dimensions which should not be duplicated
Author
K. Gerald van den Boogaart
Details
$$E_{i_1\ldots i_n j_1\ldots
j_n}=\delta_{i_1j_1}\ldots\delta_{i_nj_n}$$