detrend {Epi} | R Documentation |
The columns of the model matrix M
is projected on the
orthogonal complement to the matrix (1,t)
. Orthogonality
is defined w.r.t. an inner product defined by the weights weight
.
detrend( M, t, weight = rep(1, nrow(M)) )
M |
A model matrix. |
t |
The trend defining a subspace. A numerical vector of length
nrow(M) |
weight |
Weights defining the inner product of vectors x
and y as sum(x*w*y) .
A numerical vector of length nrow(M) , defaults to a vector of
1 s. |
The functions is intended to be used in parametrization of age-period-cohort models.
A full-rank matrix with columns orthogonal to (1,t)
.
Bendix Carstensen, Steno Diabetes Center, http://www.pubhealth.ku.dk/~bxc, with help from Peter Dalgaard.