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