program curves

c     Create the empirical and theoretical data files for the plots.

      implicit none

c     t, x, and y values
      real t(0:100),x(0:150),y(0:75)

c     pi
      real pi

c     intermediate value in vorticity computation
      real temp

c     indices
      integer i,j,n
c     maximum value of indices
      integer imax,jmax,nmax

c     format for comment lines
 10   format('# ',a)
c     the g format below can handle very large and very small plot values
 20   format(g11.4,g12.4)
c     however, the f format is much more compact and saves disk space
c     you do need to check that no numbers are printed as ****..
 30   format(f6.3,f7.3,f8.4)

c     velocity plot file
      open(1,file='veloc.plt')
      write(1,10)
     & 'Theoretical velocity plots, listing t and v_p on each line.'
      write(1,20)
      write(1,10)
     & 'First curve for white miata; data below equal',
     & 'v_p = 100% (1 - exp(-t/10)) with 0 < t < 30 seconds'
      nmax=100
      do 110 n=0,nmax
         t(n)=n*30./nmax
         write(1,20)t(n),100.*(1.-exp(-t(n)/10.))
 110  continue
c     note that a blank line is needed to separate the two curves
      write(1,20)
      write(1,10)
     & 'Second curve for red miata; data below equal',
     & 'v_p = 50% (1 - exp(-t/10)) with 0 < t < 30 seconds'
      nmax=100
      do 120 n=0,nmax
         t(n)=n*30./nmax
         write(1,20)t(n),50.*(1.-exp(-t(n)/10.))
 120  continue
      close(1)

c     acceleration plot file
      open(1,file='accel.plt')
      write(1,10)
     & 'Relative acceleration, listing a_p/a_p(0) versus t.',
     & 'a_p(t)/a_p(0) = exp(-t/10) with 0 < t < 30 seconds'
      nmax=100
      do 210 n=0,nmax
         t(n)=n*30./nmax
         write(1,20)t(n),exp(-t(n)/10.)
 210  continue
      close(1)

c     measured velocity plot file
      open(1,file='meas.plt')
      write(1,10)
     & 'Measured white Miata velocity as reported in literature.',
     & 'See citation Self12 for details.'
      nmax=10
      do 310 n=0,nmax
         t(n)=n*30./nmax
         write(1,20)t(n),100.*(1.-exp(-t(n)/10.))
 310  continue
      write(1,20)
      write(1,10)
     & 'Measured red Miata velocity as reported in literature.',
     & 'See citation Self12 for details.'
      nmax=10
      do 320 n=0,nmax
         t(n)=n*30./nmax
         write(1,20)t(n),50.*(1.-exp(-t(n)/10.))
 320  continue
      close(1)

c     set pi
      pi=4.*atan(1.)

c     streamwise vorticity of Goertler vortices.
      open(1,file='goertler.plt')
      write(1,10)
     & 'Gortler vorticity f, listing x, y, and f on each line.',
     & 'For reasons too complex to go into here, the vorticity in',
     & 'Goertler vortices always takes the form',
     & 'f = sin(pi x) sin(2 pi y)/(2 - sin(pi x) sin(2 pi y))',
     & 'However, feel free to check a random point below.'
      imax=150
      jmax=75
      do 500 i=0,imax
         write(1,30)
         x(i)=i*2./imax
         do 490 j=0,jmax
            y(j)=j*1./jmax
            temp=sin(pi*x(i))*sin(2.*pi*y(j))
            write(1,30)x(i),y(j),temp/(2.-temp)
 490     continue
 500  continue
      close(1)

      end