Wednesday 26 April 2017

Excel - Microsoft Excel Minverse Function

Description

The Excel MINVERSE function calculates the inverse of a square matrix. 

The format of the function is : 

MINVERSE( array ) 

where the array argument is an array of values representing a square matrix (i.e. has the same number of rows as columns). 

The resulting inverse matrix has the same number of rows and columns as the original supplied array. 

As the Excel Minverse function returns an array of values, the function needs to be entered as an Array Formula. 

Array Formulas: 

To input an array formula, you need to first highlight the range of cells for the function result. Type your function into the first cell of the range, and press CTRL-SHIFT-Enter.

Go to the Excel Array Formulas page for more details. 

Note that the result from the Minverse function result is calculated to approximately 16 decimal places, so you may get some rounding errors. 

Minverse Function Example
In the example below, the Excel Minverse function is used to find the inverse of the 4x4 matrix in cells A1-D4 of the example spreadsheet. The resulting 4x4 matrix is shown in cells F1-I4. 


The formula for the function can be seen in the formula bar. The curly braces { } show that the function has been input as an Array Formula. 
We can test the Minverse function by multiplying the two matrices in the above spreadsheet, using the Mmult Function. This gives the 4x4 Identity Matrix : 


Minverse Function Errors
If you get an error from your Excel Minverse function this is likely to be one of the following :

Common Errors 


Be aware also, that if you don't highlight the full range of cells for the resulting matrix, Excel will just show the part of the result that fits into the highlighted range. There will be no error message to let you know that your highlighted range is not big enough. 

This will also be the case if you fail to enter the formula as an array formula - the cell which you enter the formula into will simply show you the first entry of the resulting matrix. 










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