- Submatrix
In

mathematics , a**submatrix**is a matrix formed by selecting certain rows and columns from a bigger matrix. That is, as an array, it is cut down to those entries constrained by row "and" column.For example:$mathbf\{A\}=egin\{bmatrix\}\; a\_\{11\}\; a\_\{12\}\; a\_\{13\}\; a\_\{14\}\; \backslash \; a\_\{21\}\; a\_\{22\}\; a\_\{23\}\; a\_\{24\}\; \backslash \; a\_\{31\}\; a\_\{32\}\; a\_\{33\}\; a\_\{34\}\; end\{bmatrix\}.$Then:$mathbf\{A\}\; [1,2;\; 1,3,4]\; =egin\{bmatrix\}\; a\_\{11\}\; a\_\{13\}\; a\_\{14\}\; \backslash \; a\_\{21\}\; a\_\{23\}\; a\_\{24\}\; end\{bmatrix\}$is a submatrix of

**A**formed by rows 1,2 and columns 1,3,4. This submatrix can also be denoted by**A**(3;2) which means that it is formed by "deleting" row 3 and column 2.The above two methods are common, but there is no standard way to denote a submatrix.

The corresponding concept in

determinant theory is of "minor determinant ", that is, determinant of a**"square**" submatrix.**ee also***

block matrix

*minor (linear algebra)

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