## shallowross.m -- Plot dispersion relation for shallow Rossby waves
## given channel tilt and width.

function shallowross

  ## set constants
  kmax = 10;
  mu = 0.1;
  w = 3;
  
  ## compute dispersion relation
  k = [0:100]*kmax/100;
  pi = 3.14159;
  omega = -mu*k./(1 + k.*k + pi*pi/(w*w));

  ## do the plot
  axis([0,10,-0.04,0]);
  xlabel("scaled wavenumber");
  ylabel("scaled frequency");
  title("Rossby wave in channel -- w = 3, mu = 0.1");
  gset nokey;
  grid;
  gset terminal postscript eps;
  gset output "shallowross.eps";
  plot(k, omega);


endfunction
