lower: Lower-triangular matrix

In phiala/ecodist: Dissimilarity-Based Functions for Ecological Analysis

Lower-triangular matrix

Description

Convert a symmetric distance matrix to a column order lower triangular matrix.

Usage

  lower(m)

Arguments

m	a symmetric distance matrix.

Details

Converts a symmetric matrix, for example a dissimilarity matrix, into a column order lower-triangular matrix. This may be useful to format the input for certain clustering and ordination functions. Note that lower() used on a 1x1 matrix will return the single element, which may not be the correct behavior in all cases, while full() used on a single element will return a 2x2 matrix.

Value

column order lower triangular matrix.

Author(s)

Sarah Goslee

See Also

full, fixdmat

Examples

x.vec <- seq_len(6)
x.vec

# Make an R-style column order symmetric matrix
full(x.vec)

# Extract the lower triangle from a symmetric matrix
# in column order
lower(full(x.vec))

# Convert to or from a row order symmetric matrix
fixdmat(x.vec)
lower(fixdmat(x.vec))

fixdmat(c(1, 2, 4, 3, 5, 6))

phiala/ecodist documentation built on Nov. 5, 2023, 10:47 a.m.