# Excel MUNIT Function

Summary

The Excel MUNIT function returns a unit matrix for a given dimension, n, with a size of n x n. This resulting matrix contains ones on the main diagonal and zeros in every other position.

Purpose

Return unit matrix for a given dimension

Return value

Unix matrix of size n x n

Syntax

=MUNIT (dimension)

Arguments

**dimension**- An integer for the size of the unit matrix.

Usage notes

The MUNIT function returns a unit matrix for a given dimension, n, with a size of n x n. This resulting matrix contains ones on the main diagonal and zeros in every other position. For example, with the formula:

=MUNIT(5)

The MUNIT function returns a 5 by 5 array like this:

1 | 0 | 0 | 0 | 0 |

0 | 1 | 0 | 0 | 0 |

0 | 0 | 1 | 0 | 0 |

0 | 0 | 0 | 1 | 0 |

0 | 0 | 0 | 0 | 1 |

Because MUNIT returns an array, you must enter as a multi-cell array formula to display directly on the worksheet. To do this, make a selection or the right size, and enter MUNIT with control + shift + enter.

### Notes

- The dimension must be greater than zero
- If dimension is zero or less than zero, MUNIT will return the #VALUE error
- A unit matrix is also called an identity matrix