Mat QDet Command

Purpose

calculates the determinant of a two-dimensional floating point array which is interpreted as a matrix.

Syntax

Mat QDet x=a([i, j])[,n]

a():name of a two dimensional floating point array

x:aexp

i, j, n:integer expression

Description

Mat QDet x=a([i, j])[,n] is equivalent to Mat Det x = a([i, j])[,n] except that it's optimized for speed not accuracy. As a rule both methods deliver the same result. However, Mat Det should always be used in case of 'critical' matrices whose determinant is close to 0.

Example

OpenW # 1

Data 2,4.5,6,3.2,7,1.7,-4,12

Data -3,5,9,-2.1,6,9,11,3

Data 11.4,2.3,6,3.2,6,1.2,-5,7

Data 3,5,6,8.2,4.1,-5.2,6.2,7.9

Data 1,2.3,9,8.1,0,4.2,5,3.7

Data 4.2,7.1,8.3,9.1,-5,-3,-1,0

Data 2.0,3,9.1,0,0,7.1,-3,8.8

Data 2.1,9,3.3,4,5,-1,-2,0

Global Double a(1 To 8, 1 To 8), x, y, k%

Mat Read a()

Mat Print a(), 4, 1

Print

Mat Det x = a()//calculate the determinant

Print "Determinant with Mat Det = "; x

Print

Mat QDet y = a()//calculate the determinant

Print "Determinant with Mat QDet = "; y

Print

Print "Deviation = "; x - y

End

See Also

Mat Det, Mat Rank, Mat Inv

{Created by Sjouke Hamstra; Last updated: 15/10/2014 by James Gaite}