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Foil 27 Reductions in INDEPENDENT DO Loops

From CPS615-End of Numerical Integration and Very End of HPF Delivered Lectures of CPS615 Basic Simulation Track for Computational Science -- 24 October 96. by Geoffrey C. Fox *
Secs 116.6
Many applications of INDEPENDENT DO loops do require reductions as they are typically calculating independently quantities but storing results as parts of various averages
e.g. in High Enegry Physics Data Analysis, each measured event can be computed via an INDEPENDENT DO but one wishes to find a particular observable (histogram, scatterplot) which is averaged over each event
Financial modelling is similar
x = 0
!HPF$ INDEPENDENT, NEW(xinc), REDUCTION(x)
do i = 1 , N
  • call sub(i, xinc)
  • x = x + xinc
END DO
xinc is a separate new variable each iteration but result is accumulated into global x

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