Notation
On this page we number the matrix elements with two index numbers the first represents the column, the second the row. The index numbers start at 0 as follows:
| m00 |
m10 |
m20 |
| m01 |
m11 |
m21 |
| m02 |
m12 |
m22 |
Other notation conventions are explained on this page.
Description
The invese of a 3x3 matrix is:
| [M]-1 = 1/det[M] * |
| m11*m22 - m12*m21 |
m02*m21 - m01*m22 |
m01*m12 - m02*m11 |
| m12*m20 - m10*m22 |
m00*m22 - m02*m20 |
m02*m10 - m00*m12 |
| m10*m21 - m11*m20 |
m01*m20 - m00*m21 |
m00*m11 - m01*m10 |
|
where:
det = m00*m11*m22 + m01*m12*m20 + m02*m10*m21 - m00*m12*m21 - m01*m10*m22 - m02*m11*m20
The following calculator allows you to calculate the inverse for a 3x3 matrix. Enter the values into the matrix and then press "calc inverse " to display the result:
Code
public void inverse() {
double det = m00*m11*m22 + m01*m12*m20 + m02*m10*m21 - m00*m12*m21 - m01*m10*m22 - m02*m11*m20;
m00 = (m11*m22 - m12*m21)/det;
m01 = (m02*m21 - m01*m22)/det;
m02 = (m01*m12 - m02*m11)/det;
m10 = (m12*m20 - m10*m22)/det;
m11 = (m00*m22 - m02*m20)/det;
m12 = (m02*m10 - m00*m12)/det;
m20 = (m10*m21 - m11*m20)/det;
m21 = (m01*m20 - m00*m21)/det;
m22 = (m00*m11 - m01*m10)/det;
}
Further Information
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| see also: |
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| Correspondence about this page |
- Thank you very much to Claus for correction to determinant formula.
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