tensorA (version 0.36.1)

mark.tensor: Marks the names of a tensor with a mark

Description

This modifies the names of the dimensions in a simple and reversible way by adding a mark.

Usage

mark(X,mark,...)
# S3 method for tensor
mark(X,mark="'",i=1:level.tensor(X),...,by=NULL)
# S3 method for numeric
mark(X,mark="'",i=1:length(X),...,by=NULL)
# S3 method for character
mark(X,mark="'",i=1:length(X),...,by=NULL)

Arguments

X

A tensor or dimension to be marked

mark

a character giving the mark

i

the dimensions to be marked

…

generic arguments

by

Dimensions not to be marked. Wins in case of conflicts.

Value

A object similar to X but with marked dimensions.

Details

The concept is very important in tensor algebra since it allows to keep dimensions connected without but still distinguishable. Eventually later a function for the Riemann summing rule will make use of marks to distinguish covariate and contravariate dimensions.

See Also

delta.tensor, diag.tensor

Examples

# NOT RUN {
# The outer product
A <- to.tensor(1:4,c(a=2,b=2))
A 
# }
# NOT RUN {
<!-- %e% mark(A) -->
# }