Test if a Sparse Matrix is Symmetric

Efficient function to test if 'object' is symmetric or not.

# isSymmetric.spam(object, ...)
# S3 method for spam
isSymmetric(object, tol = 100 * .Machine$double.eps, ...)

Arguments

object

a spam matrix.

tol

numeric scalar >= 0. Smaller differences are not considered, see all.equal.spam.

...

further arguments passed to all.equal.spam.

Details

symmetry is assessed by comparing the sparsity structure of object and t(object) via the function all.equal.spam. If a difference is detected, the matrix is cleaned with cleanup and compared again.

Value

logical indicating if object is symmetric or not.

See also

all.equal.spam, cleanup.

Author

Reinhard Furrer

Examples

obj <- diag.spam(2)
isSymmetric(obj)
#> [1] TRUE

obj[1,2] <- .Machine$double.eps
isSymmetric(obj)
#> [1] TRUE
all.equal(obj, t(obj))
#> [1] "Column-sparsity structure differ (at least 1 instance(s))"
#> [2] "Row-sparsity structure differ (at least 1 instance(s))"