100 PROGRAM "Haversine.bas"
110 PRINT "Haversine distance:";HAVERSINE(36.12,-86.67,33.94,-118.4);"km"
120 DEF HAVERSINE(LAT1,LON1,LAT2,LON2)
130   OPTION ANGLE RADIANS
140   LET R=6372.8
150   LET DLAT=RAD(LAT2-LAT1):LET DLON=RAD(LON2-LON1)
160   LET LAT1=RAD(LAT1):LET LAT2=RAD(LAT2)
170   LET HAVERSINE=R*2*ASIN(SQR(SIN(DLAT/2)^2+SIN(DLON/2)^2*COS(LAT1)*COS(LAT2)))
190 END DEF