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 1.5-3

Index]