.TH "slags2.f" 3 "Sun May 26 2013" "Version 3.4.1" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME slags2.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBslags2\fP (UPPER, A1, A2, A3, B1, B2, B3, CSU, SNU, CSV, SNV, CSQ, SNQ)" .br .RI "\fI\fBSLAGS2\fP \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine slags2 (logicalUPPER, realA1, realA2, realA3, realB1, realB2, realB3, realCSU, realSNU, realCSV, realSNV, realCSQ, realSNQ)" .PP \fBSLAGS2\fP .PP \fBPurpose: \fP .RS 4 .PP .nf SLAGS2 computes 2-by-2 orthogonal matrices U, V and Q, such that if ( UPPER ) then U**T *A*Q = U**T *( A1 A2 )*Q = ( x 0 ) ( 0 A3 ) ( x x ) and V**T*B*Q = V**T *( B1 B2 )*Q = ( x 0 ) ( 0 B3 ) ( x x ) or if ( .NOT.UPPER ) then U**T *A*Q = U**T *( A1 0 )*Q = ( x x ) ( A2 A3 ) ( 0 x ) and V**T*B*Q = V**T*( B1 0 )*Q = ( x x ) ( B2 B3 ) ( 0 x ) The rows of the transformed A and B are parallel, where U = ( CSU SNU ), V = ( CSV SNV ), Q = ( CSQ SNQ ) ( -SNU CSU ) ( -SNV CSV ) ( -SNQ CSQ ) Z**T denotes the transpose of Z. .fi .PP .RE .PP \fBParameters:\fP .RS 4 \fIUPPER\fP .PP .nf UPPER is LOGICAL = .TRUE.: the input matrices A and B are upper triangular. = .FALSE.: the input matrices A and B are lower triangular. .fi .PP .br \fIA1\fP .PP .nf A1 is REAL .fi .PP .br \fIA2\fP .PP .nf A2 is REAL .fi .PP .br \fIA3\fP .PP .nf A3 is REAL On entry, A1, A2 and A3 are elements of the input 2-by-2 upper (lower) triangular matrix A. .fi .PP .br \fIB1\fP .PP .nf B1 is REAL .fi .PP .br \fIB2\fP .PP .nf B2 is REAL .fi .PP .br \fIB3\fP .PP .nf B3 is REAL On entry, B1, B2 and B3 are elements of the input 2-by-2 upper (lower) triangular matrix B. .fi .PP .br \fICSU\fP .PP .nf CSU is REAL .fi .PP .br \fISNU\fP .PP .nf SNU is REAL The desired orthogonal matrix U. .fi .PP .br \fICSV\fP .PP .nf CSV is REAL .fi .PP .br \fISNV\fP .PP .nf SNV is REAL The desired orthogonal matrix V. .fi .PP .br \fICSQ\fP .PP .nf CSQ is REAL .fi .PP .br \fISNQ\fP .PP .nf SNQ is REAL The desired orthogonal matrix Q. .fi .PP .RE .PP \fBAuthor:\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP \fBDate:\fP .RS 4 November 2011 .RE .PP .PP Definition at line 152 of file slags2\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.