isSymmetric {base} | R Documentation |
Generic function to test if object
is symmetric or not.
Currently only a matrix method is implemented.
isSymmetric(object, ...) ## S3 method for class 'matrix': isSymmetric(object, tol = 100 * .Machine$double.eps, ...)
object |
any R object; a matrix for the matrix method. |
tol |
numeric scalar >= 0. Smaller differences are not
considered, see all.equal.numeric . |
... |
further arguments passed to methods; the matrix method
passes these to all.equal . |
The matrix
method is used inside eigen
by
default to test symmetry of matrices ``up to rounding error'', using
all.equal
. It might not be appropriate in all
situations.
logical indicating if object
is symmetric or not.
eigen
which calls isSymmetric
when its
symmetric
argument is missing, as per default.
isSymmetric(D3 <- diag(3)) # -> TRUE D3[2,1] <- 1e-100 D3 isSymmetric(D3) # TRUE isSymmetric(D3, tol = 0) # FALSE for zero-tolerance