ApCoCoA-1:Num.QR

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Revision as of 08:12, 7 July 2009 by Jan (talk | contribs) (Updated example. Use Dec to make result human readable.)

Num.QR

Computes the QR-decomposition of a matrix.

Syntax

Num.QR(A:MAT):[Q:MAT,R: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 QR decomposition of a matrix using Lapack.

  • @param A Matrix A

  • @return An orthogonal matrix Q and an upper-right triangular matrix R such that Q*R=A.

Example

Points:=Mat([[1,2,3],[2,3,4],[3,4,5]]);
QR := Num.QR(Points);
Dec(QR[1]*QR[2],3);

-- CoCoAServer: computing Cpu Time = 0
-------------------------------
Mat([
  [<quote>0.999</quote>, <quote>1.999</quote>, <quote>2.999</quote>],
  [<quote>1.999</quote>, <quote>2.999</quote>, <quote>3.999</quote>],
  [<quote>2.999</quote>, <quote>3.999</quote>, <quote>4.999</quote>]
])
-------------------------------

See also

Introduction to CoCoAServer

Num.SVD

Num.EigenValues

Num.EigenValuesAndVectors

Num.EigenValuesAndAllVectors