SUBROUTINE SICI

PURPOSE
   COMPUTES THE SINE AND COSINE INTEGRAL

USAGE
   CALL SICI(SI,CI,X)

DESCRIPTION OF PARAMETERS
   SI	 - THE RESULTANT VALUE SI(X)
   CI	 - THE RESULTANT VALUE CI(X)
   X	 - THE ARGUMENT OF SI(X) AND CI(X)

REMARKS
   THE ARGUMENT VALUE REMAINS UNCHANGED

SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED
   NONE

METHOD
   DEFINITION
   SI(X)=INTEGRAL(SIN(T)/T)
   CI(X)=INTEGRAL(COS(T)/T)
   EVALUATION
   REDUCTION OF RANGE USING SYMMETRY.
   DIFFERENT APPROXIMATIONS ARE USED FOR ABS(X) GREATER
   THAN 4 AND FOR ABS(X) LESS THAN 4.
   REFERENCE
   LUKE AND WIMP, 'POLYNOMIAL APPROXIMATIONS TO INTEGRAL
   TRANSFORMS',  MATHEMATICAL TABLES AND OTHER AIDS TO
   COMPUTATION, VOL. 15, 1961, ISSUE 74, PP. 174-178.