nMatrix-class {Matrix} | R Documentation

## Class "nMatrix" of Non-zero Pattern Matrices

### Description

The `nMatrix` class is the virtual “mother” class of all non-zero pattern (or simply pattern) matrices in the Matrix package.

### Slots

Common to all matrix object in the package:

`Dim`:

  Object of class `"integer"` - the dimensions of the matrix - must be an integer vector with exactly two non-negative values.

`Dimnames`:

  list of length two; each component containing NULL or a `character` vector length equal the corresponding `Dim` element.

### Methods

There is a bunch of coercion methods (for `as(..)`), e.g.,

coerce

  `signature(from = "matrix", to = "nMatrix")`: Note that these coercions (must) coerce `NA`s to non-zero, hence conceptually `TRUE`. This is particularly important when `sparseMatrix` objects are coerced to `"nMatrix"` and hence to `nsparseMatrix`.

coerce

  `signature(from = "dMatrix", to = "nMatrix")`, and

coerce

  `signature(from = "lMatrix", to = "nMatrix")`: For dense matrices with `NA`s, these coercions are valid since Matrix version 1.2.0 (still with a `warning` or a `message` if `"Matrix.warn"`, or `"Matrix.verbose"` `options` are set.)

coerce

  `signature(from = "nMatrix", to = "matrix")`: ...

coerce

  `signature(from = "nMatrix", to = "dMatrix")`: ...

coerce

  `signature(from = "nMatrix", to = "lMatrix")`: ...

— — —

Additional methods contain group methods, such as

Ops

  `signature(e1 = "nMatrix", e2 = "....")`, ...

Arith

  `signature(e1 = "nMatrix", e2 = "....")`, ...

Compare

  `signature(e1 = "nMatrix", e2 = "....")`, ...

Logic

  `signature(e1 = "nMatrix", e2 = "....")`, ...

Summary

  `signature(x = "nMatrix", "....")`, ...

### See Also

The classes `lMatrix`, `nsparseMatrix`, and the mother class, `Matrix`.

### Examples

    getClass("nMatrix")

    L3 <- Matrix(upper.tri(diag(3)))
    L3 # an "ltCMatrix"
    as(L3, "nMatrix") # -> ntC*

    ## similar, not using Matrix()
    as(upper.tri(diag(3)), "nMatrix")# currently "ngTMatrix"

[Package Matrix version 1.2-6 Index]