R: Virtual Class of Symmetric Matrices in package:Matrix

symmetricMatrix-class {Matrix} | R Documentation

## Virtual Class of Symmetric Matrices in package:Matrix

### Description

The virtual class of symmetric matrices, `"symmetricMatrix"`, from the package Matrix contains numeric and logical, dense and sparse matrices, e.g., see the examples.

The main use is in methods (and C functions) that can deal with all symmetric matrices.

### Slots

`uplo`:

  Object of class `"character"`. Must be either "U", for upper triangular, and "L", for lower triangular.

`Dim, Dimnames`:

  The dimension (a length-2 `"integer"`) and corresponding names (or `NULL`), inherited from the `Matrix`, see there.

`factors`:

  a list of matrix factorizations, also from the `Matrix` class.

### Extends

Class `"Matrix"`, directly.

### Methods

There's a C function `symmetricMatrix_validity()` called by the internal validity checking functions.

### See Also

Classes `triangularMatrix`, and, e.g., `dsyMatrix` for numeric dense matrices, or `lsCMatrix` for a logical sparse matrix class.

### Examples

    showClass("symmetricMatrix")

    ## The names of direct subclasses:
    scl <- getClass("symmetricMatrix")@subclasses
    directly <- sapply(lapply(scl, slot, "by"), length) == 0
    names(scl)[directly]

[Package Matrix version 1.0-6 Index]