dgCMatrix-class {Matrix} | R Documentation

## Compressed, sparse, column-oriented numeric matrices

### Description

The `dgCMatrix` class is a class of sparse numeric matrices in the compressed, sparse, column-oriented format. In this implementation the non-zero elements in the columns are sorted into increasing row order. `dgCMatrix` is the “standard” class for sparse numeric matrices in the Matrix package.

### Objects from the Class

Objects can be created by calls of the form `new("dgCMatrix", ...)`, more typically via `as(*, "CsparseMatrix")` or similar. Often however, more easily via `Matrix(*, sparse = TRUE)`, or most efficiently via `sparseMatrix()`.

### Slots

`x`:

  Object of class `"numeric"` - the non-zero elements of the matrix.

...

  all other slots are inherited from the superclass `"CsparseMatrix"`.

### Methods

Matrix products (e.g., crossprod-methods), and (among other)

coerce

  `signature(from = "matrix", to = "dgCMatrix")`

coerce

  `signature(from = "dgCMatrix", to = "matrix")`

coerce

  `signature(from = "dgCMatrix", to = "dgTMatrix")`

diag

  `signature(x = "dgCMatrix")`: returns the diagonal of `x`

dim

  `signature(x = "dgCMatrix")`: returns the dimensions of `x`

image

  `signature(x = "dgCMatrix")`: plots an image of `x` using the `levelplot` function

solve

  `signature(a = "dgCMatrix", b = "...")`: see `solve-methods`, notably the extra argument `sparse`.

lu

  `signature(x = "dgCMatrix")`: computes the LU decomposition of a square `dgCMatrix` object

### See Also

Classes `dsCMatrix`, `dtCMatrix`, `lu`

### Examples

    (m <- Matrix(c(0,0,2:0), 3,5))
    str(m)
    m[,1]

[Package Matrix version 1.2-17 Index]