Raise tensor indices

r() raises specified tensor indices using a covariant metric tensor provided in g. Note that the order of indices is not preserved due to performance reasons. An error is thrown if the specified indices do not exist or are not in the correct position.

Usage

r(x, ..., g = NULL)

Arguments

x

A labeled tensor object, created by %_% or tensor().

...

Any number of index expressions. The indices need to occur in x.

g

A covariant metric tensor, a "metric_field" object. See metric_field() to create a new metric tensor, or use predefined metrics, e.g. g_eucl_cart(). If no metric tensor is provided, indices are raised/lowered with the identity matrix.

Value

A modified tensor object.

See also

Other tensor operations: Ops.tensor(), asym(), kron(), l(), subst(), sym()