lower_tri: Lower and Upper triangular of a matrix

In Rfast: A Collection of Efficient and Extremely Fast R Functions

Lower and Upper triangular of a matrix

Description

Lower/upper triangular matrix.

Usage

lower_tri(x, suma = FALSE, diag = FALSE)
upper_tri(x, suma = FALSE, diag = FALSE)
lower_tri.assign(x, v, diag = FALSE)
upper_tri.assign(x, v, diag = FALSE)

Arguments

x	A matrix with data or a vector with 2 values which is the dimension of the logical matrix to be returned with the upper or lower triangular filled with "TRUE".
v	A numeric vector for assign to the lower/upper triangular.
suma	A logical value for returning the sum of the upper or lower triangular. By default is "FALSE". Works only if argument "x" is matrix.
diag	A logical value include the diagonal to the result.

Value

Get a lower/upper triangular logical matrix with values TRUE/FALSE, a vector with the values of a lower/upper triangular, the sum of the upper/lower triangular if suma is set TRUE or assign to the lower/upper (only for large matrices) triangular. You can also include diagonal with any operation if argument diag is set to "TRUE".

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[e-mail]>.

See Also

rowMins, colFalse, nth, rowrange, rowMedians, rowVars, colTrue

Examples

x <- matrix(runif(10*10),10,10)

all.equal(lower_tri(c(10,10)),lower.tri(x))

all.equal(lower_tri(x),x[lower.tri(x)])

#all.equal(upper_tri(c(10,10)),upper.tri(x))

#all.equal(upper_tri(x),x[upper.tri(x)])



#all.equal(lower_tri(c(10,10),diag = TRUE),lower.tri(x,diag = TRUE))

#all.equal(lower_tri(x,diag = TRUE),x[lower.tri(x,diag = TRUE)])

#all.equal(upper_tri(c(10,10),diag = TRUE),upper.tri(x,diag = TRUE))

#all.equal(upper_tri(x,diag = TRUE),x[upper.tri(x,diag = TRUE)])

all.equal(lower_tri.assign(x,diag = TRUE,v=rep(1,1000)),x[lower.tri(x,diag = TRUE)]<-1)

all.equal(upper_tri.assign(x,diag = TRUE,v=rep(1,1000)),x[upper.tri(x,diag = TRUE)]<-1)

x<-NULL

Rfast documentation built on Nov. 9, 2023, 5:06 p.m.