The MUNIT function returns the unit matrix for the specified dimension.

  • This function was introduced in Excel 2013 and so is not available in earlier versions.

Syntax

=MUNIT(dimension)

Arguments

Argument Description
dimension An integer specifying the dimension of the unit matrix that you want to return

  dimension must be greater than 0 

Inputting Array Formulas: To input an array formula,

  1. highlight the range of cells for the function result, 
  2. type the function into the first cell of the range, and
  3. press CTRL-SHIFT-ENTER

Examples

  A B C D E
1 Formula Result Notes
2 {=MUNIT(3)} 1 0 0 Returns the identity matrix of dimension 3
3   0 1 0  
4   0 0 1  

Note: The formula displayed in A2 is an array formula entered by following the instructions above for entering an array formula. The curly brackets, { and }, are not entered by the user. Excel applies these to show the formula has been input as an array formula.

Common Function Error(s)

Problem What went wrong
#VALUE! Occurs if either:

  the dimension argument is less than or equal to zero
  the dimension argument is not recognized as a numeric value
#N/A Occurs in cells outside the range of the resulting matrix, e.g. in the example above, had we highlighted cells F7-H10 before entering the MINVERSE function, cells, F10-H10 are not part of the resulting matrix and therefore will return the #N/A error

MUNIT uses the following equation:  

    \[    1_{n \times n} = \left[ \begin{array}{cccc}1 & 0 & \dots & 0  \\0 & 1 & \dots & 0  \\\vdots & \vdots & \ddots & \vdots  \\0 & 0 & \dots & 1  \end{array} \right]    \]