program logistic_again

      write(*,*)'What is your initial x value?'
      read(*,*)x_ini
      write(*,*)'How many generations?'
      read(*,*)n
      xmax=n
      m=1

      if(pgopen('/xwin')<=0)stop
      call pgenv(0.0,xmax,0.0,1.0,0,0) 
 100  write(*,*)'What is your r value?'
      read(*,*)r
      call pgmove(1.0,x_ini)
      x=x_ini

      do i=1,n
        x = 4*r*x*(1-x)
        g=i+1
        call pgdraw(g,x)
      end do

      m=m+1
      call pgsci(mod(m,16))

 102  write(*,*)'Again?(Yes=1,No=0)'
      read(*,*)i_again
      if(i_again==1)goto 100
      if(i_again==0)stop
      goto 102 

      call pgclos

      end