.TH "las2" 3 "Wed Feb 7 2024 11:30:40" "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
las2 \- las2: 2x2 triangular SVD
.SH SYNOPSIS
.br
.PP
.SS "Functions"

.in +1c
.ti -1c
.RI "subroutine \fBdlas2\fP (f, g, h, ssmin, ssmax)"
.br
.RI "\fBDLAS2\fP computes singular values of a 2-by-2 triangular matrix\&. "
.ti -1c
.RI "subroutine \fBslas2\fP (f, g, h, ssmin, ssmax)"
.br
.RI "\fBSLAS2\fP computes singular values of a 2-by-2 triangular matrix\&. "
.in -1c
.SH "Detailed Description"
.PP 

.SH "Function Documentation"
.PP 
.SS "subroutine dlas2 (double precision f, double precision g, double precision h, double precision ssmin, double precision ssmax)"

.PP
\fBDLAS2\fP computes singular values of a 2-by-2 triangular matrix\&.  
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
 DLAS2  computes the singular values of the 2-by-2 matrix
    [  F   G  ]
    [  0   H  ]\&.
 On return, SSMIN is the smaller singular value and SSMAX is the
 larger singular value\&.
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIF\fP 
.PP
.nf
          F is DOUBLE PRECISION
          The (1,1) element of the 2-by-2 matrix\&.
.fi
.PP
.br
\fIG\fP 
.PP
.nf
          G is DOUBLE PRECISION
          The (1,2) element of the 2-by-2 matrix\&.
.fi
.PP
.br
\fIH\fP 
.PP
.nf
          H is DOUBLE PRECISION
          The (2,2) element of the 2-by-2 matrix\&.
.fi
.PP
.br
\fISSMIN\fP 
.PP
.nf
          SSMIN is DOUBLE PRECISION
          The smaller singular value\&.
.fi
.PP
.br
\fISSMAX\fP 
.PP
.nf
          SSMAX is DOUBLE PRECISION
          The larger singular value\&.
.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
\fBFurther Details:\fP
.RS 4

.PP
.nf
  Barring over/underflow, all output quantities are correct to within
  a few units in the last place (ulps), even in the absence of a guard
  digit in addition/subtraction\&.

  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\&.

  Underflow is harmless if underflow is gradual\&. Otherwise, results
  may correspond to a matrix modified by perturbations of size near
  the underflow threshold\&.
.fi
.PP
 
.RE
.PP

.SS "subroutine slas2 (real f, real g, real h, real ssmin, real ssmax)"

.PP
\fBSLAS2\fP computes singular values of a 2-by-2 triangular matrix\&.  
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
 SLAS2  computes the singular values of the 2-by-2 matrix
    [  F   G  ]
    [  0   H  ]\&.
 On return, SSMIN is the smaller singular value and SSMAX is the
 larger singular value\&.
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIF\fP 
.PP
.nf
          F is REAL
          The (1,1) element of the 2-by-2 matrix\&.
.fi
.PP
.br
\fIG\fP 
.PP
.nf
          G is REAL
          The (1,2) element of the 2-by-2 matrix\&.
.fi
.PP
.br
\fIH\fP 
.PP
.nf
          H is REAL
          The (2,2) element of the 2-by-2 matrix\&.
.fi
.PP
.br
\fISSMIN\fP 
.PP
.nf
          SSMIN is REAL
          The smaller singular value\&.
.fi
.PP
.br
\fISSMAX\fP 
.PP
.nf
          SSMAX is REAL
          The larger singular value\&.
.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
\fBFurther Details:\fP
.RS 4

.PP
.nf
  Barring over/underflow, all output quantities are correct to within
  a few units in the last place (ulps), even in the absence of a guard
  digit in addition/subtraction\&.

  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\&.

  Underflow is harmless if underflow is gradual\&. Otherwise, results
  may correspond to a matrix modified by perturbations of size near
  the underflow threshold\&.
.fi
.PP
 
.RE
.PP

.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.