SUBROUTINE MATH
C** MATH
 10    TYPE 1001
 1001  FORMAT($,' FUNCTION> ')
       ACCEPT *,IFUNCT
       IF(IFUNCT .EQ. 99)GO TO 999
       GO TO(110,120,130,140,150,160)IFUNCT
       TYPE *,'    FUNCTIONS AVAILABLE:'
       TYPE *,'      1 = ADD X1+X2'
        TYPE *,'      2 = SUBTRACT X1-X2'
       TYPE *,'      3 = DEVIDE X1/X2'
       TYPE *,'      4 = MULTIPLY X1*X2'
       TYPE *,'      5 = DISTANCE,ANGLE,DIRECTION'
       TYPE *,'      6 = SQUARE ROOT'
       TYPE *,'       99 = RETURN'
       GO TO 10
 110   TYPE 1010
 1010  FORMAT($,' INPUT X1,X2> ')
       ACCEPT *,X1,X2
       SUM = X1 + X2
       TYPE 1011,X1,X2,SUM
 1011  FORMAT(2X,F9.3,' + ',F9.2,' = ',F9.2)
       GO TO 10
 120  TYPE 1010
       ACCEPT *,X1,X2
      TYPE 1020,X1,X2,X1-X2
 1020  FORMAT(2X,F9.2,' - ',F9.2,' = ',F9.2)
       GO TO 10
 130   TYPE 1010
       ACCEPT *,X1,X2
       TYPE 1030,X1,X2,X1/X2
 1030 FORMAT(2X,F9.2,' /',F9.2,' = ',F9.2)
       GO TO 10
 140   TYPE 1010
       ACCEPT *,X1,X2
       TYPE 1040,X1,X2,X1*X2
 1040  FORMAT(2X,F9.2,' * ',F9.2,' = ',F9.2)
       GO TO 10
 150   TYPE 1050
 1050  FORMAT($,' INPUT X1,Y1,X2,Y2> ')
       ACCEPT *,X1,Y1,X2,Y2
       DIST = SQRT((X2-X1)**2 + (Y2-Y1)**2)
       ANGLE = ATAN2((Y2-Y1),(X2-X1))
       IF(ANGLE .LT. 0.0)ANGLE = 6.28318 + ANGLE
       DIRN = ANGLE*8./6.28318 +1
       TYPE 1051,X1,Y1,XW2,Y2
 1051  FORMAT(2X,'X1,Y1 = ',2F8.4,' 2,Y2 = ',2F8.4)
       TYPE 1052,DIST,ANGLE,DIRN
 1052  FORMAT(2X,'DISTANCE,ANGLE,DIRECTION = ',3F8.4)
       GO TO 10
 160   TYPE 1060
 1060  FORMAT($,' INPUT X1>')
       ACCEPT *,X1
       SQRTX1 = SQRT(X1)
       TYPE 1061,X1,SQRTX1
 1061  FORMAT(2X,' X1 = ',F8.4,' SQRT = ',F8.4)
       GO TO 10
 999    RETURN
        END