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 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()`

.

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

Classes `'>dsCMatrix`

,
`'>dtCMatrix`

, `lu`

```
# NOT RUN {
(m <- Matrix(c(0,0,2:0), 3,5))
str(m)
m[,1]
# }
```

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