%
% PURPOSE: Compute and plot k4 from SlowTri_SemiCUR3.
%
% These values were obtained visually, making use of axis([]), and are
% the values of data(:,torque) and sgauge where omega**2 (om2) = 2e6.
  y1 = (1820+1920)/2;
  y2 = (-1830-1700)/2;
  k2m = (y1 - y2)/4e6;
  sg1 = (820+870)/2;
  sg2 = (-780-760)/2;
  k4m = (sg1 - sg2)/4e6;
%
% Note that k2m is in centi-Newton-meters/(rpm)**2.

  om2 = data(:,vel).*abs(data(:,vel));

  figure(5)
  clf
  plot(om2, [data(:,torque), sgauge, k2m*om2, k4m*om2])
  grid on
  xlabel('RPM**2')
  ylabel('Torque, N-cm and Thrust N')
  legend('Torque Cmd','Meas Thrust','k2','k4',2)

  disp(['1/K2 = ',num2str(100/k2m,6),...
        ' K2 is the SS omega to torque parameter; Nm/(rpm)^2'])
  disp(['1/K4 = ',num2str(1/k4m,4),...
        ' K4 is the SS omega to thrust param; N/(rpm)^2'])