rcond: rcond
In RBigData/kazaam: Tools for Tall Distributed Matrices

Description Usage Arguments Details Value Communication Examples

Reciprocal condition number estimate.

1 2	## S4 method for signature 'shaq' rcond(x, norm = c("O", "I", "1"), triangular = FALSE, ...)

`x`	A shaq.
`norm, triangular, ...`	Arguments passed to `base::rcond()`.

The estimate is computed by first forming the R matrix from a QR. Currently this involves first computing a crossproduct, so the estimate can be thought of as being fairly liberal. Afterwards, the condition number is estimated by calling base::rcond() on the local R matrix.

A number.

The operation is completely local except for forming the crossproduct, which is an allreduce() call, quadratic on the number of columns.

## Not run: 
library(kazaam)
x = ranshaq(runif, 10, 3)
rc = rcond(x)
comm.print(rc)

x = expand(matrix(1:30, 10))
rc = rcond(x)
comm.print(rc)

finalize()

## End(Not run)