# ApCoCoA-1:Num.LeastSquaresQR

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Revision as of 16:03, 22 April 2009 by Stadler (talk | contribs) (ApCoCoA:Numerical.LeastSquaresQR moved to ApCoCoA:Num.LeastSquaresQR)

## Numerical.LeastSquaresQR

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

### Syntax

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

### 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. Please also note that you will have to use an ApCoCoAServer with enabled BLAS/LAPACK support.

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 decompostion of Mat is used to find the solution.

#### 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