File: RECP.FT of Tape: Various/ETH/eth11-1

(Source file text) 

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C     ..................................................................
C
C        FUNCTION RECP
C
C        PURPOSE
C           CALCULATE RECIPROCAL OF AN ELEMENT. THIS IS A FORTRAN
C           FUNCTION SUBPROGRAM WHICH MAY BE USED AS AN ARGUMENT BY
C           SUBROUTINE MFUN.
C
C        USAGE
C           RECP(E)
C
C        DESCRIPTION OF PARAMETERS
C           E - MATRIX ELEMENT
C
C        REMARKS
C           RECIPROCAL OF ZERO IS TAKEN TO BE 1.0E75
C
C        SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED
C           NONE
C
C        METHOD
C           RECIPROCAL OF ELEMENT E IS PLACED IN RECP
C
C     ..................................................................
C
      FUNCTION RECP(E)
C
      BIG=1.0E37
C
C        TEST ELEMENT FOR ZERO
C
      IF(E) 1,2,1
C
C        IF NON-ZERO, CALCULATE RECIPROCAL
C
    1 RECP=1.0/E
      RETURN
C
C        IF ZERO, SET EQUAL TO INFINITY
C
    2 RECP=SIGN(BIG,E)
      RETURN
      END
C

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