2-Jul-96, 6:54:35
Routine Save for Trigonometry Library function $%TAN^MATH
 ;
 ; Unless otherwise noted, the code below
 ; was approved in document X11/95-12
 ;
 ; If corrections have been applied,
 ; first the original line appears,
 ; with three semicolons at the beginning of the line.
 ;
 ; Then the source of the correction is acknowledged,
 ; then the corrected line appears, followed by a
 ; line containing three semicolons.
 ;
TAN(X,PREC) ;
 New L,LIM,K,S,SIGN,VALUE
 ;
 ;;; Set:X[":" X=$%DMSDEC^MATH(X,12)
 ; Winfried Gerum (8 June 1995)
 ;    Comment: The official description does not mention than
 ;             the function may also be called with the first
 ;             parameter in degrees, minutes and seconds.
 Set:X[":" X=$%DMSDEC^MATH(X)
 ;;;
 ;
 Set PREC=$Get(PREC,11)
 Set X=X#(2*$%PI^MATH())
 Set (VALUE,L)=X,SIGN=-1
 Set LIM=$Select((PREC+3)'>11:PREC+3,1:11),@("LIM=1E-"_LIM)
 For K=3:2 Do  Quit:($Translate(L,"-")<LIM)  Set SIGN=SIGN*-1
 . Set L=L/(K-1)*X/K*X,VALUE=VALUE+(SIGN*L)
 . Quit
 Set S=VALUE
 Set X=X#(2*$%PI^MATH())
 Set (VALUE,L)=1,SIGN=-1
 Set LIM=$Select((PREC+3)'>11:PREC+3,1:11),@("LIM=1E-"_LIM)
 For K=2:2 Do  Quit:($Translate(L,"-")<LIM)  Set SIGN=SIGN*-1
 . Set L=L*X*X/(K-1*K),VALUE=VALUE+(SIGN*L)
 . Quit
 If 'VALUE Quit "INFINITE"
 Quit S/VALUE
 ;===
 ;
 ;
 ;