How can I fix "Undefined operator '-' for input arguments of type 'matlab.ui.Figure'"

I am working on the function to plot some figures. However, when I run the program that call that funciton that error appears. How can I fix it?

This is the part of the function where the error appears:

si=figure-1; %% The error is here

for i=1:outputs

figure(si+i);

subplot(211)

plot(Y(i,:),'bx'); hold on

plot(y2(i,:),'ro');hold off

if outputs==1,

title('Observations = x Network output=o')

else

title(['Observations = x Network output=o (output # ',num2str(i) ')'])

end

grid

Answer 1

[Jon]

figure is a MATLAB command that will open up a new figure.

MATLAB is telling you, it does not make any sense to subtract 1 from a function that is opening a new figure.

If you want to find out what the current figure number is so you can start numbering from there you could do something like

figNo = get(gcf,'Number')

where gcf means get current figure, and you are asking for its Number property

[santiago santiago]

Thanks now it works

Answer 2

[Steven Lord]

In releases prior to the introduction of the new graphics system in release R2014b, Handle Graphics functions like figure often returned a number representing a handle to a graphics object.

It was possible to perform arithmetic on those numbers, though there's no guarantee that the result of those arithmetic operations would return a handle to an object.

With the new graphics system figure returns a figure object and that figure object does not have the arithmetic operators defined on it.

Based on what you're trying to do (plot each results on a separate figure) you don't need to do arithmetic. Just call figure (no inputs, no outputs) to open a new figure for each set of results you want to plot.

x = 0:360;
for k = 1:4
    figure
    axis([0 360 -1 1])
    plot(x, sind(k*x))
end

[santiago santiago]

Thanks