Subscript a Packet Cost Object

DESCRIPTION:
Allows the user to extract values from a 1D or 2D packet costs object by using crystal names, subscripts or levels.

USAGE:
x[i, ..., level]
x[i, ..., level] <- value
x[[i]]
x[[i]] <- value
x$i
x$i <- value

REQUIRED ARGUMENTS:
x:
an object of class "pcosts" or "pcosts.2d".
level:
a vector of integers indicating which level(s) to be subscripted, see details below. If present, i will be ignored.
i:
a vector of crystal names or positive integers.

OPTIONAL ARGUMENTS:
value:
a numeric vector, replacement value for the relevant piece of x.

VALUE:
a numeric vector of costs.

DETAILS:
Both 1D and 2D packet costs are stored as a vector. Each element corresponds to a crystal in a 1D or 2D packet table. Subscripting by level causes all the costs corresponding to the specified level(s) be subscripted.

SEE ALSO:
pcosts , pcosts.object , pcosts.2d.objects , wp.costs.2d , cp.costs.2d, crystal.names .