`accumarray`

allows to aggregate items of an array in various ways, potentially applying some function to the items in the process. `accumarray`

can be thought of as a lightweight reducer (see also: Introduction to MapReduce ).

This topic will contain common scenarios where `accumarray`

is especially useful.

- accumarray(subscriptArray, valuesArray)
- accumarray(subscriptArray, valuesArray, sizeOfOutput)
- accumarray(subscriptArray, valuesArray, sizeOfOutput, funcHandle)
- accumarray(subscriptArray, valuesArray, sizeOfOutput, funcHandle, fillVal)
- accumarray(subscriptArray, valuesArray, sizeOfOutput, funcHandle, fillVal, isSparse)

Parameter | Details |
---|---|

`subscriptArray` | Subscript matrix, specified as a vector of indices, matrix of indices, or cell array of index vectors. |

`valuesArray` | Data, specified as a vector or a scalar. |

`sizeOfOutput` | Size of output array, specified as a vector of positive integers. |

`funcHandle` | Function to be applied to each set of items during aggregation, specified as a function handle or `[]` . |

`fillVal` | Fill value, for when `subs` does not reference each element in the output. |

`isSparse` | Should the output be a sparse array? |

- Introduced in MATLAB v7.0.

- "Under-appreciated
`accumarray`

",*by Loren Shure*, February 20, 2008. `accumarray`

in the official MATLAB documentation.