orthMat: Calculate an orthonormal basis

In HGray384/pcaNet: Probabilistic principal components analysis - covariance estimation and network reconstruction

Description

A copied (unexported) function from pcaMethods. ONB = orth(mat) is an orthonormal basis for the range of matrix mat. That is, ONB' * ONB = I, the columns of ONB span the same space as the columns of mat, and the number of columns of ONB is the rank of mat.

Usage

orthMat(mat, skipInac = FALSE)

Arguments

mat	matrix – matrix to calculate the orthonormal basis of
skipInac	logical – do not include components with precision below .Machine$double.eps if TRUE

Value

orthonormal basis for the range of mat

Author(s)

Wolfram Stacklies

References

Stacklies, W., Redestig, H., Scholz, M., Walther, D. and Selbig, J., 2007. doi.

See Also

orth

Examples

set.seed(102)
X <- matrix(rnorm(10), 5, 2)
norm(X[,1], type="2")
norm(X[,2], type="2")
t(X[,1])%*%X[,2]
Xorth <- orthMat(X)
# now unit norms
norm(Xorth[,1], type="2")
norm(Xorth[,2], type="2")
# and zero dot product
t(Xorth[,1])%*%Xorth[,2]

HGray384/pcaNet documentation built on Nov. 14, 2020, 11:11 a.m.