# ApCoCoA-1:Num.LeastSquaresQR

From ApCoCoAWiki

## Num.LeastSquaresQR

Calculates the least squares solution to the general problem Ax=b

### Syntax

Num.LeastSquaresQR(Mat:MAT, Vec:MAT):MAT;

### Description

*Please note:* The function(s) explained on this page is/are using the *ApCoCoAServer*. You will have to start the ApCoCoAServer in order to use it/them.

Calculates the least squares solution to the general problem Ax=b, when there is no exact solution. The matrix Mat must have the same number of rows as Vec.

The QR decomposition of Mat is used to find the solution.

@param

*Mat*Matrix A@param

*Vec*Vector B in matrix form.@return The least squares solution to Ax=b.

#### Example

Dec(Num.LeastSquaresQR([[1,1],[0,1],[1,1]],[[0],[1],[0]]),2); -- CoCoAServer: computing Cpu Time = 0 ------------------------------- Mat([ ["-0.99"], ["1"] ]) -------------------------------

### See also