program mandel

  real :: xmin, xmax
  real :: ymin, ymax

  real :: dx, x
  real :: dy, y
  integer :: i, j
  integer :: it, itmax
  integer, parameter :: nsize = 700
  complex  :: c, z

! initialize variables
  itmax = 5000
  xmin = -2
  xmax = 2
  ymin = -2
  ymax = 2
  
! determine dx, dy for grid based on initial values
  n = nsize
  dx = (xmax - xmin)/(n-1)
  dy = (ymax - ymin)/(n-1)

! loop over the grid  
  do i = 1, n
    do j = 1, n
! find x,y and set the c to the location in the complex plane
      x = (i-1) * dx + xmin
      y = (j-1) * dy + ymin
      c = cmplx(x,y)
      z = c

! determine the number of iterations needed 
      it = 0
      do while (it < itmax .and. abs(z) < 2)
        it = it + 1
        z = z*z + c
      enddo

! print the result to a data file
      write(11,'(2i6, i5)') i,j,it
    enddo
  enddo



end program mandel