isSymmetric-methods {Matrix} R Documentation

## Methods for Function isSymmetric in Package 'Matrix'

### Description

isSymmetric(M) returns a logical indicating if M is a symmetric matrix. This (now) is a base function with a default method for the traditional matrices of class "matrix". Methods here are defined for virtual Matrix classes such that it works for all objects inheriting from class Matrix.

forceSymmetric, symmpart, and the formal class (and subclasses) "symmetricMatrix".

### Examples

isSymmetric(Diagonal(4)) # TRUE of course
M <- Matrix(c(1,2,2,1), 2,2)
isSymmetric(M) # TRUE (*and* of formal class "dsyMatrix")
isSymmetric(as(M, "dgeMatrix")) # still symmetric, even if not "formally"
isSymmetric(triu(M)) # FALSE

## Look at implementations:
showMethods("isSymmetric", includeDefs=TRUE)# "ANY": base's S3 generic; 6 more


[Package Matrix version 1.4-1 Index]