fold function

Fold a square matrix

The function fold sums corresponding below and above diagonal elements of a square matrix to form a triangular matrix.

fold(X, lower = TRUE)

Arguments

• X: a square matrix
• lower: logical. If lower=TRUE a lower triangular matrix is formed, if not an upper triangular matrix.

Details

Useful for constructing triangular matrices of genotype counts

Returns

A matrix

Author(s)

Jan Graffelman jan.graffelman@upc.edu

See Also

lower.tri, upper.tri

Examples

allelenames <- paste("A",11:13,sep="")
allele1 <- factor(c("A11","A11","A12","A12","A13","A12"),levels=allelenames)
allele2 <- factor(c("A11","A12","A12","A13","A13","A11"),levels=allelenames)
GC  <- table(allele1,allele2)
GC  <- as.matrix(unclass(GC))
GCf <- fold(GC)