DLASV2 - Online Linux Manual Page

Section : 1
Updated : November 2008
Source : LAPACK auxiliary routine (version 3.2)
Note : LAPACK auxiliary routine (version 3.2)
NAMEDLASV2 - computes the singular value decomposition of a 2-by-2 triangular matrix [ F G ] [ 0 H ]
SYNOPSISSUBROUTINE DLASV2(  F, G, H, SSMIN, SSMAX, SNR, CSR, SNL, CSL )  DOUBLE PRECISION CSL, CSR, F, G, H, SNL, SNR, SSMAX, SSMIN
PURPOSEDLASV2 computes the singular value decomposition of a 2-by-2 triangular matrix
   [ F G ]
   [ 0 H ]. On return, abs(SSMAX) is the larger singular value, abs(SSMIN) is the smaller singular value, and (CSL,SNL) and (CSR,SNR) are the left and right singular vectors for abs(SSMAX), giving the decomposition
   [ CSL SNL ] [ F G ] [ CSR -SNR ] = [ SSMAX 0 ]
   [-SNL CSL ] [ 0 H ] [ SNR CSR ] [ 0 SSMIN ].
ARGUMENTSF (input) DOUBLE PRECISION  The (1,1) element of the 2-by-2 matrix. G (input) DOUBLE PRECISION  The (1,2) element of the 2-by-2 matrix. H (input) DOUBLE PRECISION  The (2,2) element of the 2-by-2 matrix. SSMIN (output) DOUBLE PRECISION  abs(SSMIN) is the smaller singular value. SSMAX (output) DOUBLE PRECISION  abs(SSMAX) is the larger singular value. SNL (output) DOUBLE PRECISION  CSL (output) DOUBLE PRECISION The vector (CSL, SNL) is a unit left singular vector for the singular value abs(SSMAX). SNR (output) DOUBLE PRECISION  CSR (output) DOUBLE PRECISION The vector (CSR, SNR) is a unit right singular vector for the singular value abs(SSMAX).
FURTHER DETAILSAny input parameter may be aliased with any output parameter. Barring over/underflow and assuming a guard digit in subtraction, all output quantities are correct to within a few units in the last place (ulps).
In IEEE arithmetic, the code works correctly if one matrix element is infinite.
Overflow will not occur unless the largest singular value itself overflows or is within a few ulps of overflow. (On machines with partial overflow, like the Cray, overflow may occur if the largest singular value is within a factor of 2 of overflow.)
Underflow is harmless if underflow is gradual. Otherwise, results may correspond to a matrix modified by perturbations of size near the underflow threshold.
0
Johanes Gumabo
Data Size   :   7,645 byte
man-dlasv2.lBuild   :   2025-03-22, 13:26   :  
Visitor Screen   :   x
Visitor Counter ( page / site )   :   4 / 2,337,799
Visitor ID   :     :  
Visitor IP   :   216.73.216.115   :  
Visitor Provider   :   AMAZON-02   :  
Provider Position ( lat x lon )   :   39.962500 x -83.006100   :   x
Provider Accuracy Radius ( km )   :   20   :  
Provider City   :   Columbus   :  
Provider Province   :   Ohio ,   :   ,
Provider Country   :   United States   :  
Provider Continent   :   North America   :  
Visitor Recorder   :   Version   :  
Visitor Recorder   :   Library   :  
Online Linux Manual Page   :   Version   :   Online Linux Manual Page - Fedora.40 - march=x86-64 - mtune=generic - 25.03.22
Online Linux Manual Page   :   Library   :   lib_c - 24.10.03 - march=x86-64 - mtune=generic - Fedora.40
Online Linux Manual Page   :   Library   :   lib_m - 24.10.03 - march=x86-64 - mtune=generic - Fedora.40
Data Base   :   Version   :   Online Linux Manual Page Database - 24.04.13 - march=x86-64 - mtune=generic - fedora-38
Data Base   :   Library   :   lib_c - 23.02.07 - march=x86-64 - mtune=generic - fedora.36
Very long time ago, I have the best tutor, Wenzel Svojanovsky. If someone knows the email address of Wenzel Svojanovsky, please send an email to johanesgumabo@gmail.com.
Help me, linux0001.com will expire on July 16, 2025. I have no money to renew it. View detail
If error, please print screen and send to johanes_gumabo@yahoo.co.id
Under development. Support me via PayPal.