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Matrix (version 1.5-4)

# dgCMatrix-class: 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")`

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`

## Examples

Run this code
``````(m <- Matrix(c(0,0,2:0), 3,5))
str(m)
m[,1]
## regression test: this must give a validity-check error:
stopifnot(inherits(try(new("dgCMatrix", i = 0:1, p = 0:2,
x = c(2,3), Dim = 3:4)),
"try-error"))

``````

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