.TH "SRC/dlae2.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
SRC/dlae2.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBdlae2\fP (a, b, c, rt1, rt2)"
.br
.RI "\fBDLAE2\fP computes the eigenvalues of a 2-by-2 symmetric matrix\&. "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine dlae2 (double precision a, double precision b, double precision c, double precision rt1, double precision rt2)"

.PP
\fBDLAE2\fP computes the eigenvalues of a 2-by-2 symmetric matrix\&.  
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
 DLAE2  computes the eigenvalues of a 2-by-2 symmetric matrix
    [  A   B  ]
    [  B   C  ]\&.
 On return, RT1 is the eigenvalue of larger absolute value, and RT2
 is the eigenvalue of smaller absolute value\&.
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIA\fP 
.PP
.nf
          A is DOUBLE PRECISION
          The (1,1) element of the 2-by-2 matrix\&.
.fi
.PP
.br
\fIB\fP 
.PP
.nf
          B is DOUBLE PRECISION
          The (1,2) and (2,1) elements of the 2-by-2 matrix\&.
.fi
.PP
.br
\fIC\fP 
.PP
.nf
          C is DOUBLE PRECISION
          The (2,2) element of the 2-by-2 matrix\&.
.fi
.PP
.br
\fIRT1\fP 
.PP
.nf
          RT1 is DOUBLE PRECISION
          The eigenvalue of larger absolute value\&.
.fi
.PP
.br
\fIRT2\fP 
.PP
.nf
          RT2 is DOUBLE PRECISION
          The eigenvalue of smaller absolute 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
  RT1 is accurate to a few ulps barring over/underflow\&.

  RT2 may be inaccurate if there is massive cancellation in the
  determinant A*C-B*B; higher precision or correctly rounded or
  correctly truncated arithmetic would be needed to compute RT2
  accurately in all cases\&.

  Overflow is possible only if RT1 is within a factor of 5 of overflow\&.
  Underflow is harmless if the input data is 0 or exceeds
     underflow_threshold / macheps\&.
.fi
.PP
 
.RE
.PP

.PP
Definition at line \fB101\fP of file \fBdlae2\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.