QVSUM 3 "04 October 2003" "Version 1.00"

Table of contents


NAME

qvsum - Quadruple-precision vector sum

SYNOPSIS

Fortran (77, 90, 95, HPF):
f77 [ flags ] file(s) ... -L/usr/local/lib -lgjl
REAL*16 FUNCTION qvsum(x,n)
INTEGER             n
REAL*16             x(*)
C (K&R, 89, 99), C++ (98):
cc [ flags ] -I/usr/local/include file(s) ... -L/usr/local/lib -lgjl
Use
#include <gjl.h>
to get this prototype:
void qvsum(fortran_quadruple_precision * x_,
           const fortran_integer * n_);

NB: The definition of C/C++ data types fortran_ xxx, and the mapping of Fortran external names to C/C++ external names, is handled by the C/C++ header file. That way, the same function or subroutine name can be used in C, C++, and Fortran code, independent of compiler conventions for mangling of external names in these programming languages.


DESCRIPTION

Return an accurate estimate of the sum x(1) + x(2) + ... + x(n) using Kahan error-compensating summation.

AUTHORS

The algorithms and code are described in detail in the paper
Fast Gaussian Quadrature for Two Classes of Logarithmic Weight Functions
in ACM Transactions on Mathematical Software, Volume ??, Number ??, Pages ????--???? and ????--????, 20xx, by
Nelson H. F. Beebe
Center for Scientific Computing
University of Utah
Department of Mathematics, 110 LCB
155 S 1400 E RM 233
Salt Lake City, UT 84112-0090
Tel: +1 801 581 5254
FAX: +1 801 581 4148
Email: beebe@math.utah.edu, beebe@acm.org, beebe@computer.org
WWW URL: http://www.math.utah.edu/~beebe
and
James S. Ball
University of Utah
Department of Physics
Salt Lake City, UT 84112-0830
USA
Tel: +1 801 581 8397
FAX: +1 801 581 6256
Email: ball@physics.utah.edu
WWW URL: http://www.physics.utah.edu/people/faculty/ball.html