Description Usage Arguments Value Slots Extends Creating Objects Methods Author(s) See Also Examples

The `matter_mat`

class implements on-disk matrices.

1 2 3 4 5 6 7 8 | ```
## Instance creation
matter_mat(data, datamode = "double", paths = NULL,
filemode = ifelse(all(file.exists(paths)), "rb", "rb+"),
offset = c(0, cumsum(sizeof(datamode) * extent)[-length(extent)]),
extent = if (rowMaj) rep(ncol, nrow) else rep(nrow, ncol),
nrow = 0, ncol = 0, rowMaj = FALSE, dimnames = NULL, ...)
## Additional methods documented below
``` |

`data` |
An optional data matrix which will be initially written to the data on disk if provided. |

`datamode` |
A 'character' vector giving the storage mode of the data on disk. Allowable values are the C types ('char', 'uchar', short', 'ushort', 'int', 'uint', 'long', 'ulong', 'float') and their R equivalents ('raw', 'logical', 'integer', 'numeric'). |

`paths` |
A 'character' vector of the paths to the files where the data are stored. If 'NULL', then a temporary file is created using |

`filemode` |
The read/write mode of the files where the data are stored. This should be 'rb' for read-only access, or 'rb+' for read/write access. |

`offset` |
A vector giving the offsets in number of bytes from the beginning of each file in 'paths', specifying the start of the data to be accessed for each file. |

`extent` |
A vector giving the length of the data for each file in 'paths', specifying the number of elements of size 'datamode' to be accessed from each file. |

`nrow` |
An optional number giving the total number of rows. |

`ncol` |
An optional number giving the total number of columns. |

`rowMaj` |
Whether the data should be stored in row-major order (as opposed to column-major order) on disk. Defaults to 'FALSE', for efficient access to columns. Set to 'TRUE' for more efficient access to rows instead. |

`dimnames` |
The names of the matrix dimensions. |

`...` |
Additional arguments to be passed to constructor. |

An object of class `matter_mat`

.

`data`

:This slot stores the information about locations of the data on disk and within the files.

`datamode`

:The storage mode of the accessed data when read into R. This should a 'character' vector of length one with value 'integer' or 'numeric'.

`paths`

:A 'character' vector of the paths to the files where the data are stored.

`filemode`

:The read/write mode of the files where the data are stored. This should be 'rb' for read-only access, or 'rb+' for read/write access.

`chunksize`

:The maximum number of elements which should be loaded into memory at once. Used by methods implementing summary statistics and linear algebra. Ignored when explicitly subsetting the dataset.

`length`

:The length of the data.

`dim`

:Either 'NULL' for vectors, or an integer vector of length one of more giving the maximal indices in each dimension for matrices and arrays.

`names`

:The names of the data elements for vectors.

`dimnames`

:Either 'NULL' or the names for the dimensions. If not 'NULL', then this should be a list of character vectors of the length given by 'dim' for each dimension. This is always 'NULL' for vectors.

`ops`

:Delayed operations to be applied on atoms.

`matter`

`matter_mat`

instances can be created through `matter_mat()`

or `matter()`

.

Standard generic methods:

`x[i, j, ..., drop], x[i, j] <- value`

:Get or set the elements of the matrix. Use

`drop = NULL`

to return a subset of the same class as the object.`x %*% y`

:Matrix multiplication. At least one matrix must be an in-memory R matrix (or vector).

`crossprod(x, y)`

:Alias for t(x) %*% y.

`tcrossprod(x, y)`

:Alias for x %*% t(y).

`cbind(x, ...), rbind(x, ...)`

:Combine matrices by row or column.

`t(x)`

:Transpose a matrix. This is a quick operation which only changes metadata and does not touch the on-disk data.

Kylie A. Bemis

1 2 | ```
x <- matter_mat(1:100, nrow=10, ncol=10)
x[]
``` |

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