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CentOS 7.0 - man page for classq (centos section 3)

classq.f(3)							      LAPACK							       classq.f(3)

NAME
classq.f -
SYNOPSIS
Functions/Subroutines subroutine classq (N, X, INCX, SCALE, SUMSQ) CLASSQ updates a sum of squares represented in scaled form. Function/Subroutine Documentation subroutine classq (integerN, complex, dimension( * )X, integerINCX, realSCALE, realSUMSQ) CLASSQ updates a sum of squares represented in scaled form. Purpose: CLASSQ returns the values scl and ssq such that ( scl**2 )*ssq = x( 1 )**2 +...+ x( n )**2 + ( scale**2 )*sumsq, where x( i ) = abs( X( 1 + ( i - 1 )*INCX ) ). The value of sumsq is assumed to be at least unity and the value of ssq will then satisfy 1.0 .le. ssq .le. ( sumsq + 2*n ). scale is assumed to be non-negative and scl returns the value scl = max( scale, abs( real( x( i ) ) ), abs( aimag( x( i ) ) ) ), i scale and sumsq must be supplied in SCALE and SUMSQ respectively. SCALE and SUMSQ are overwritten by scl and ssq respectively. The routine makes only one pass through the vector X. Parameters: N N is INTEGER The number of elements to be used from the vector X. X X is COMPLEX array, dimension (N) The vector x as described above. x( i ) = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n. INCX INCX is INTEGER The increment between successive values of the vector X. INCX > 0. SCALE SCALE is REAL On entry, the value scale in the equation above. On exit, SCALE is overwritten with the value scl . SUMSQ SUMSQ is REAL On entry, the value sumsq in the equation above. On exit, SUMSQ is overwritten with the value ssq . Author: Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Date: September 2012 Definition at line 107 of file classq.f. Author Generated automatically by Doxygen for LAPACK from the source code. Version 3.4.2 Tue Sep 25 2012 classq.f(3)