projector {dae} | R Documentation |
The class "projector
" is the
subclass of the class "matrix
"
in which matrices are square, symmetric and idempotent.
The function projector
tests whether a matrix
satisfies these criteria and if it does creates a
"projector
" object, computing the
projector's degrees of freedom and adding them to the object.
projector(Q)
Q |
The |
In checking that the matrix
is square, symmetric and
idempotent, the equality of the matrix
with either its
transpose or square is tested. In this, a difference in elements is
considered to be zero if it is less than daeTolerance
, which is
initially set to .Machine$double.eps ^ 0.5
(about 1.5E-08).
The function set.daeTolerance
can
be used to change daeTolerance
.
An object of Class "projector
" that
consists of a square, summetric, idempotent matrix
and
degrees of freedom (rank) of the matrix.
Chris Brien
degfree
, correct.degfree
in package dae.
projector
for further information about this class.
## set up a 2 x 2 mean operator that takes the mean of a vector of 2 values
m <- matrix(rep(0.5,4), nrow=2)
## create an object of class projector
proj.m <- projector(m)
## check that it is a valid projector
is.projector(proj.m)