prospectr (version 0.2.7)

blockNorm: Sum of squares block weighting

Description

Sum of squares block weighting: allows to scale blocks of variables, but keeping the relative weights of the variables inside a block.

Usage

blockNorm(X, targetnorm = 1)

Value

a list with components Xscaled, the scaled matrix and f, the scaling factor

Arguments

X

a numeric matrix to transform (optionally a data frame that can be coerced to a numerical matrix).

targetnorm

desired sum of squares for a block of variables (default = 1)

Author

Antoine Stevens

Details

The function computes a scaling factor, which, multiplied by the input matrix, produces a matrix with a pre--determined sum of squares.

References

Eriksson, L., Johansson, E., Kettaneh, N., Trygg, J., Wikstrom, C., and Wold, S., 2006. Multi- and Megavariate Data Analysis. MKS Umetrics AB.

See Also

blockScale, standardNormalVariate, detrend

Examples

X <- matrix(rnorm(100), ncol = 10)
# Block normalize to sum of square equals to 1
res <- blockNorm(X, targetnorm = 1)
sum(res$Xscaled^2) # check