Add plot to doxygen for CoordinateLimitForce

[chrisdembia]

Here's what I made for the TGCS example, based on feedback from Colin Smith.

hopper = BuildHopper();

state = hopper.initSystem();

import org.opensim.modeling.*;

N = 400;
hipAngle = linspace(-110, 130, N); % degrees.
force = zeros(1, N);
clf = CoordinateLimitForce.safeDownCast(hopper.getComponent('hip/hipLigaments'));
for i = 1:N
    hopper.setStateVariableValue(state, 'hip/hipFlexion/value', pi/180.*hipAngle(i));
    hopper.setStateVariableValue(state, 'hip/hipFlexion/speed', 0);
    hopper.realizeDynamics(state);
    force(i) = clf.calcLimitForce(state);
end
close all;
h = figure(1);
set(gcf, 'PaperPositionMode', 'auto');
set(h, 'Position', [0, 0, 400, 200]);
plot(hipAngle, force, 'k', 'LineWidth', 2);
ylim([-400, 400]);
xlim([-110, 130]);
hold on;

plot([-110, 130], [0, 0], 'k', 'LineWidth', 0.5);
plot(-90*[1, 1], [-400, 400], 'k--', 'LineWidth', 1.5);
plot(-100*[1, 1], [-400, 200], 'k--', 'LineWidth', 1.5);
plot(110*[1, 1], [-400, 400], 'k--', 'LineWidth', 1.5);
plot(120*[1, 1], [-200, 400], 'k--', 'LineWidth', 1.5);

t = text(-90, -200, 'lower limit');
t.Rotation = 90;
t.HorizontalAlignment = 'center';
t.VerticalAlignment = 'top';

t = text(110, -200, 'upper limit');
t.Rotation = 90;
t.HorizontalAlignment = 'center';
t.VerticalAlignment = 'bottom';

t = text(-95, -200, 'transition');
t.HorizontalAlignment = 'center';
quiver(-90, -150, -10, 0, 'k--', 'LineWidth', 1.5);

t = text(-105, 350, 'lower stiffness');

t = text(125, -350, 'upper stiffness');
t.HorizontalAlignment = 'right';

xticks([-100, -90, 110, 120]);
ylabel('Force (N)');
xlabel('Joint Angle (degrees)');
breakxaxis([-85, 105])

print -dpng -r300 CoordinateLimitForce.png

[aymanhab]

@jenhicks Do you know why this was made a 4.4? @tkuchida your student recently updated doxygen for StepFunction can that be reused here? Thanks

[tkuchida]

(The StepFunction plot was added in PR #3169.) It's a different function so the image can't be reused here. The figure shown up top could be added to the documentation verbatim as an example (when the parameters are the following…), or could be generalized as was done for the Millard muscle curves (e.g., https://github.com/opensim-org/opensim-core/blob/master/doc/images/fig_ForceVelocityCurve.png).

[aymanhab]

Fixed in PR #3201 Please verify in latest build artifact