DQCPSI(3)

SYNOPSIS
SUBROUTINE DQCPSI (LUN, KPRINT, IPASS)

NAME
dqcpsi - Quick check for DPSIFN.

LIBRARY
SLATEC

KEYWORDS
QUICK CHECK

AUTHOR
Amos, D. E., (SNLA)

DESCRIPTION
ABSTRACT * A DOUBLE PRECISION ROUTINE * DQCPSI IS A QUICK CHECK ROUTINE WHICH EXERCISES THE MAJOR LOOPS IN SUBROUTINE DPSIFN(X,N,KODE,M,ANS,NZ,IERR) FOR DERIVATIVES OF THE PSI FUNCTION. FOR N=0, THE PSI FUNCTIONS ARE CALCULATED EXPLICITLY AND CHECKED AGAINST EVALUATIONS FROM DPSIFN. FOR N.GT.0, CONSISTENCY CHECKS ARE MADE BY COMPARING A SEQUENCE AGAINST SINGLE EVALUATIONS OF DPSIFN, ONE AT A TIME. IF THE RELATIVE ERROR IS LESS THAN 1000 TIMES THE MAXIMUM OF UNIT ROUNDOFF AND 1.0D-18, THEN THE TEST IS PASSED--IF NOT, THEN X, THE VALUES TO BE COMPARED, THE RELATIVE ERROR AND PARAMETERS KODE AND N ARE WRITTEN ON LOGICAL UNIT 6 WHERE N IS THE ORDER OF THE DERIVATIVE AND KODE IS A SELECTION PARAMETER DEFINED IN THE PROLOGUE TO DPSIFN. FUNCTIONS I1MACH AND D1MACH MUST BE INITIALIZED ACCORDING TO THE PROLOGUE IN EACH FUNCTION FOR THE MACHINE ENVIRONMENT BEFORE DQCPSI OR DPSIFN CAN BE EXECUTED.

ROUTINES CALLED
D1MACH, DPSIFN

REVISION HISTORY (YYMMDD)
820601 DATE WRITTEN
890911 Removed unnecessary intrinsics. (WRB)
890911 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)