FORTRAN 77 "Error: Unclassifiable statement at (1)"

Question

This program:

C This program calculates cos(x**2)

      PROGRAM COSX_SQUARE
      IMPLICIT NONE
      INTEGER a
      REAL y, r

      PRINT*, 'INPUT THE DEGREE'
      PRINT*, 'BETWEEN 0 AND 360'
      READ*, a

      a*(3.141592/180) = y

C This part determines minus sign and calculates the function

      IF (a .GT. 90) THEN
         r = -(1-(y**4)/2+(y**8)/24-(y**12)/720+(y**16)/40320)
      ELSEIF (a .GE. 270) THEN
         r = 1-(y**4)/2+(y**8)/24-(y**12)/720+(y**16)/40320
      ELSEIF (a .GT. 360) THEN
         PRINT*, 'INVALID DEGREE'
         PRINT*, 'DEGREE MUST BE BETWEEN 0 AND 360'
      ELSEIF (a .LT. 0) THEN
         PRINT*, 'INVALID DEGREE'
         PRINT*, 'DEGREE MUST BE BETWEEN 0 AND 360'
      END IF

      PRINT*, 'THE RESULT OF COS', a, 'SQUARE IS = ', r

      STOP
      END

Gives this error:

    a*(3.141592/180)=y                                
    1
Error: Unclassifiable statement at (1)

I already defined a as INTEGER. Why this error keeps coming?

Answer 1

Yep. It is an expression which begins a statement. Maybe change it to

  y = a*(3.141592/180)

if that is what you really meant.