Difference between revisions of "ApCoCoA-1:Num.QR"
From ApCoCoAWiki
(Updated example. Use Dec to make result human readable.) |
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<example> | <example> | ||
Points:=Mat([[1,2,3],[2,3,4],[3,4,5]]); | Points:=Mat([[1,2,3],[2,3,4],[3,4,5]]); | ||
| − | Num.QR(Points); | + | 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>] |
| − | ]) | + | ]) |
| − | |||
| − | |||
| − | |||
| − | |||
------------------------------- | ------------------------------- | ||
</example> | </example> | ||
Revision as of 08:12, 7 July 2009
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
