isSymmetric-methods {Matrix}R Documentation

Methods for Function isSymmetric in Package 'Matrix'


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.

See Also

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


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]