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35 lines
1.1 KiB
Fortran
35 lines
1.1 KiB
Fortran
*DECK ALI
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FUNCTION ALI (X)
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C***BEGIN PROLOGUE ALI
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C***PURPOSE Compute the logarithmic integral.
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C***LIBRARY SLATEC (FNLIB)
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C***CATEGORY C5
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C***TYPE SINGLE PRECISION (ALI-S, DLI-D)
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C***KEYWORDS FNLIB, LOGARITHMIC INTEGRAL, SPECIAL FUNCTIONS
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C***AUTHOR Fullerton, W., (LANL)
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C***DESCRIPTION
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C
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C ALI(X) computes the logarithmic integral; i.e., the
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C integral from 0.0 to X of (1.0/ln(t))dt.
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C
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C***REFERENCES (NONE)
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C***ROUTINES CALLED EI, XERMSG
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C***REVISION HISTORY (YYMMDD)
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C 770601 DATE WRITTEN
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C 890531 Changed all specific intrinsics to generic. (WRB)
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C 890531 REVISION DATE from Version 3.2
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C 891214 Prologue converted to Version 4.0 format. (BAB)
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C 900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ)
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C 900326 Removed duplicate information from DESCRIPTION section.
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C (WRB)
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C***END PROLOGUE ALI
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C***FIRST EXECUTABLE STATEMENT ALI
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IF (X .LE. 0.0) CALL XERMSG ('SLATEC', 'ALI',
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+ 'LOG INTEGRAL UNDEFINED FOR X LE 0', 1, 2)
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IF (X .EQ. 1.0) CALL XERMSG ('SLATEC', 'ALI',
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+ 'LOG INTEGRAL UNDEFINED FOR X = 1', 2, 2)
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C
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ALI = EI (LOG(X) )
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C
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RETURN
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END
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