--- rpl/lapack/lapack/dlassq.f 2010/12/21 13:53:33 1.7 +++ rpl/lapack/lapack/dlassq.f 2011/11/21 20:42:59 1.8 @@ -1,9 +1,112 @@ +*> \brief \b DLASSQ +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download DLASSQ + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE DLASSQ( N, X, INCX, SCALE, SUMSQ ) +* +* .. Scalar Arguments .. +* INTEGER INCX, N +* DOUBLE PRECISION SCALE, SUMSQ +* .. +* .. Array Arguments .. +* DOUBLE PRECISION X( * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> DLASSQ returns the values scl and smsq such that +*> +*> ( scl**2 )*smsq = x( 1 )**2 +...+ x( n )**2 + ( scale**2 )*sumsq, +*> +*> where x( i ) = X( 1 + ( i - 1 )*INCX ). The value of sumsq is +*> assumed to be non-negative and scl returns the value +*> +*> scl = max( scale, abs( x( i ) ) ). +*> +*> scale and sumsq must be supplied in SCALE and SUMSQ and +*> scl and smsq are overwritten on SCALE and SUMSQ respectively. +*> +*> The routine makes only one pass through the vector x. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The number of elements to be used from the vector X. +*> \endverbatim +*> +*> \param[in] X +*> \verbatim +*> X is DOUBLE PRECISION array, dimension (N) +*> The vector for which a scaled sum of squares is computed. +*> x( i ) = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n. +*> \endverbatim +*> +*> \param[in] INCX +*> \verbatim +*> INCX is INTEGER +*> The increment between successive values of the vector X. +*> INCX > 0. +*> \endverbatim +*> +*> \param[in,out] SCALE +*> \verbatim +*> SCALE is DOUBLE PRECISION +*> On entry, the value scale in the equation above. +*> On exit, SCALE is overwritten with scl , the scaling factor +*> for the sum of squares. +*> \endverbatim +*> +*> \param[in,out] SUMSQ +*> \verbatim +*> SUMSQ is DOUBLE PRECISION +*> On entry, the value sumsq in the equation above. +*> On exit, SUMSQ is overwritten with smsq , the basic sum of +*> squares from which scl has been factored out. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date November 2011 +* +*> \ingroup auxOTHERauxiliary +* +* ===================================================================== SUBROUTINE DLASSQ( N, X, INCX, SCALE, SUMSQ ) * -* -- LAPACK auxiliary routine (version 3.2) -- +* -- LAPACK auxiliary routine (version 3.4.0) -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -* November 2006 +* November 2011 * * .. Scalar Arguments .. INTEGER INCX, N @@ -13,47 +116,6 @@ DOUBLE PRECISION X( * ) * .. * -* Purpose -* ======= -* -* DLASSQ returns the values scl and smsq such that -* -* ( scl**2 )*smsq = x( 1 )**2 +...+ x( n )**2 + ( scale**2 )*sumsq, -* -* where x( i ) = X( 1 + ( i - 1 )*INCX ). The value of sumsq is -* assumed to be non-negative and scl returns the value -* -* scl = max( scale, abs( x( i ) ) ). -* -* scale and sumsq must be supplied in SCALE and SUMSQ and -* scl and smsq are overwritten on SCALE and SUMSQ respectively. -* -* The routine makes only one pass through the vector x. -* -* Arguments -* ========= -* -* N (input) INTEGER -* The number of elements to be used from the vector X. -* -* X (input) DOUBLE PRECISION array, dimension (N) -* The vector for which a scaled sum of squares is computed. -* x( i ) = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n. -* -* INCX (input) INTEGER -* The increment between successive values of the vector X. -* INCX > 0. -* -* SCALE (input/output) DOUBLE PRECISION -* On entry, the value scale in the equation above. -* On exit, SCALE is overwritten with scl , the scaling factor -* for the sum of squares. -* -* SUMSQ (input/output) DOUBLE PRECISION -* On entry, the value sumsq in the equation above. -* On exit, SUMSQ is overwritten with smsq , the basic sum of -* squares from which scl has been factored out. -* * ===================================================================== * * .. Parameters ..