YSESLOG ;SLC/DCM-UTILITY ROUTINE TO CALCULATE LOGARITHMS TO BASE e OR BASE 10 ; 10/18/88  16:54 ;
 ;;5.01;MENTAL HEALTH;;Dec 30, 1994
 ;DECISION EXPERT SYSTEM (VERSION 1.0) FOR MENTAL HEALTH PACKAGE - DWIGHT MCDANIEL / REGION 5 ISC, SLC
 ;PASS NUMBER TO A5AESLOG IN VARIABLE ESLN; LOGARIGHM OF NUMBER RETURNED AS ESY
 ;DECIMAL ACCURACY IS 8 DECIMAL DIGITS
CALC S ESLU=ESL1-.707106781187/(ESL1+.70710681187),ESLV=ESLU*ESLU
 S ESLU=.434259751292*ESLV+.576584342056*ESLV+.961800762286*ESLV+2.885390072738*ESLU
 Q
EXIT S ESLS=0 S:ESY<0 ESLS=1,ESY=-ESY S ESY=$E(ESY+.000000005,1,ESY["."+8),ESY=$E("-",ESLS)_ESY D CONV:ESE S:$E(ESY,$L(ESY))["0" ESY=$E(ESY,1,$L(ESY)-1)
EXIT1 K ESLI,ESL1,ESLS,ESLU,ESLV,ESLZ Q
CONV I ESY>10 F ESLI=0:1 Q:ESY<10  S ESY=ESY/10
 I ESY<1 F ESLI=0:-1 Q:ESY>1  S ESY=ESY*10
 S ESY=$E("-",ESLS)_ESY_"E"_ESLI Q
 ;
LOG ; Called by routine YSEUT
 D TEST G EXIT1:ESAB I ESLN=1 S (ESY,ESAB)=0 G EXIT1
 D SCALE,CALC S ESY=ESY+ESLU/3.321928096+ESLZ G EXIT
 ;
LN ; Called by routine YSEUT
 D TEST G EXIT1:ESAB I ESLN=1 S (ESY,ESAB)=0 G EXIT1
 D SCALE,CALC S ESY=ESLZ*3.321928094887+ESY+ESLU/1.442695040889 G EXIT ;1.442695040889=1/Ln(2) 3.32192809489=Ln(10)/Ln(2)
TEST S ESAB=1 Q:'$D(ESLN)  S:'$D(ESE) ESE=0 Q:'(ESLN?1N.N!(ESLN?1N.N1"."1N.N)!(ESLN?1"."1N.N))
 Q:ESLN>1E24!(ESLN=0)  S ESAB=0 Q
SCALE S ESLI=ESLN\1,ESL1=$E(ESLN#1,2,40) ;LI=INT,L1=FRACT PARTS OF LN
 S:ESLI=0 ESLI="" S ESLZ=$L(ESLI) S:ESL1=0 ESL1="" S ESL1=ESLI_ESL1
 F ESY=1:1 Q:$E(ESL1)>0  S ESLZ=ESLZ-1,ESL1=$E(ESL1,2,40)
 F ESY=0:1:3 Q:$E(ESL1)>4  S ESL1=ESL1*2
 S ESL1="."_ESL1,ESY=-.5-ESY
 Q