mul.tensor {tensorA} | R Documentation |
Performs a tensor multiplication like tensor(), but with named indices, keeping dimnames, and vectorized.
mul.tensor(X,i=c(),Y,j=i,by=NULL)
X |
a tensor to be multiplied |
i |
numeric or character vector specifying the dimension to be used in the multiplication for X |
Y |
a tensor to be multiplied |
j |
numeric or character vector specifying the dimension to be used in the multiplication for Y |
by |
the by dimensions if present and not mentioned in i or j are
used as sequence dimensions. tensors in these dimensions are
processed in parallel. So in this dimension the product is neither
inner nor outer but parallel like |
Say
X_{i_1… i_n h_1 … h_l}
and
Y_{j_1… j_n k_1 … k_m}
the the result is:
E_{h_1… h_l k_1 … k_m}= ∑_{i_1,…,i_n} X_{i_1… i_n h_1 … h_l}Y_{j_1… j_n k_1 … k_m}
This is an full outer product with i,j not given and a full inner product product of i=dim(X)
The tensor product of X and Y with respect to the regarding dimensions.
K. Gerald van den Boogaart
to.tensor
, %e%
,
%r%
, diagmul.tensor
,
einstein.tensor
, riemann.tensor
,
solve.tensor
A <- to.tensor(1:20,c(A=2,B=2,C=5)) B <- to.tensor(1:20,c(D=2,B=2,E=5)) mul.tensor(A,"A",A,"B")