Using fnplt in UIAxes

I learned that fnplt takes a function as an input.

fnplt(cscvn([1 0 -1 -1 0 1;0 1 0 0 -1 0]));

The line above works fine.However, I could not do that in the UIAxes.

fnplt(app.UIAxes,cscvn([1 0 -1 -1 0 1;0 1 0 0 -1 0]));

The line above would produce the following error:

Input is not a function.

Error in fnplt (line 72)

f = fn2fm(f);

What is my error here and how can I fix it?

[Derek Vasquez]

This is not exactly a solution, but I found a workaround to a similar problem by using something like this

t = linspace(0,5,100);
traj = fnval(cscvn([1 0 -1 -1 0 1;0 1 0 0 -1 0]),t);
plot(app.UIAxes,traj(1,:),traj(2,:))

Hope this helps someone!

Answer 1

[Biraj Khanal]

cscvn constructs spline in a piecewise polynomial form. as Derek has written in his comment, I had to evaluate the spline with fnval at certain breaks before plotting them .

For example

x = [-10,-8,-4,0,4,6,10];
y = [1 8 10 11 10 9 1];
s = cscvn([x;y]);
s_breaks = s.breaks;
new_y = fnval(s,linspace(s.breaks(1),s.breaks(end),100));
plot(app.UIAxes,new_y(1,:),new_y(2,:));