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Anonymous function to class property method.

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I have a situation somewhat like the following mockup:
absfoo.m
classdef (Abstract) absfoo
methods (Abstract)
[f] = objfun(o, x)
[c, ceq] = confun(o, x)
end
end
confoo.m
classdef confoo < absfoo
methods
function [f] = objfun(o, x)
f = sin(sum(x.^2));
end
function [c, ceq] = confun(o, x)
c(1) = cos(0.1+x(1).^2);
c(2) = x(1)+x(2);
ceq = [];
end
end
end
bar.m
classdef bar
properties
myfoo
end
methods
function runme(o)
x0 = [0 1];
fmincon(@o.myfoo.objfun,x0,[],[],[],[],[],[],@o.myfoo.confun)
end
end
end
runscr.m
clear all
mf = confoo()
b = bar();
b.myfoo = mf;
b.runme()
Running runscr results in an error message similar to this:
Undefined function or variable 'o.myfoo.objfun'.
Error in fmincon (line 536)
If I add a wrapper method in bar, I can work around this error -- but I'd like to be able to do without the wrapper.
Edited to add commas to fmincon argument list and also empty lb, ub arguments per Steven's correction.

Accepted Answer

Steven Lord
Steven Lord on 10 Jan 2020
Note: you shouldn't call your class bar as that already has a meaning in MATLAB.
Use this:
fmincon(@(x) objfun(o.myfoo, x),x0,[],[],[],[],[],[],@(x) confun(o.myfoo, x))
The object o.myfoo isa confoo while x will be a double array. This means confoo is the dominant class. By the procedure listed here MATLAB will call the objfun method of the confoo class to call when fmincon tries to evaluate the anonymous objective function. The same holds for confun.
In addition to changing the objective and nonlinear constraint functions I had to add commas between the A, b, Aeq, and beq inputs as well as adding the lb and ub inputs as empty inputs.
  5 Comments
Walter Roberson
Walter Roberson on 10 Jan 2020
Also because of the way that it examines arguments to deduce which calling sequence you are using, there are circumstances under which it can confuse an extra parameter as being one of the regular parameters. This is documented deep in the comments of the code.

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