Matrix wrapping refers to adding blank rows between rows of a matrix to show the structure of the matrix more clearly. This operation will not affect the addition, subtraction, multiplication and division of the matrix, nor will it change the symbol of the matrix.

This is because the matrix has no value, only symbolic attributes, so there is no sign change problem. The result is still a matrix after proper operation of the matrix. Generally, the rank of a matrix is found without evaluation. Only the rows (columns) in the determinant need to be changed. It is essentially a constant. Since it is a constant, there are positive and negative. When calculating, special attention should be paid to the change of symbols. For example, if two rows (columns) are exchanged, the sign will change.

Matters needing attention in matrix regression

A matrix can swap rows. The newline character is to select two different rows from the matrix and exchange their positions, so that the matrix has the order of different rows. When performing the elimination method, if a row is missing a specific element and the next elimination method is realized, you need to exchange rows to add a specific element in order to perform the next operation according to the elimination method.

Exchanging rows is an important means in the process of matrix inversion. By exchanging rows, the calculation steps can be simplified, the amount of calculation can be reduced, and the efficiency of solving matrix inverse can be improved. For example, affine transformation in geometry, operation a? B is affine transformation, such as translation, rotation and compression. The final effect is the same as translational compression.