Calculate distance between 2 points

C call:

C     CALL PTH038 (X1,Y1,X2,Y2,RABST,LUWRIT,LUREAD)

C     

C     The following variables must be defined beforehand:

C     

C     X1/Y1  : Coordinate first point

C     X2/Y2  : Coordinate second point

C     RABST  : Distance (return value)

C     LUWRIT : is not evaluated, but must be specified

C     LUREAD : is not evaluated, but must be specified

C     

C     Example:

C     ---------------------------------------

C     Calculate distance between two points

C     ---------------------------------------

      X1 = 50.0

      Y1 = 50.0

      X2 = 80.0

      Y2 = 100.0

      CALL PTH038 (X1,Y1,X2,Y2,RABST,LUWRIT,LUREAD)