Modify function_handle in Simulink matlab function
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Hi there,
I want to modfy the type of function_handle in Simulink Matlab function. Here is the codes
nonConOption = 1;
nonlcon = [];
A = [];
b = [];
Aeq = [];
beq = [];
x0 = [1/4,1/4];
fun = @(x)100*(x(2)-x(1)^2)^2 + (1-x(1))^2;
lb = [0,0.2];
ub = [0.5,0.8];
if nonConOption == 1
nonlcon = @circlecon;
end
x = fmincon(fun,x0,A,b,Aeq,beq,lb,ub,nonlcon)
function [c,ceq] = circlecon(x)
c = (x(1)-1/3)^2 + (x(2)-1/3)^2 - (1/3)^2;
ceq = [];
end
But the error reports
It is not possible to write a value of type function_handle to a variable of type double. Code generation does not support changing the type by assignment. To investigate the cause of the type mismatch, check the previous assignment or input type setting.
How to create an empty function_handle?
I don't want to repeat the call fmincon like
if nonConOption == 1
x = fmincon(fun,x0,A,b,Aeq,beq,lb,ub,@circlecon)
else
x = fmincon(fun,x0,A,b,Aeq,beq,lb,ub,[])
end
best regards,
Tianyuan
采纳的回答
Paul
2025-3-23
Assuming the ultimate goal is to have nonConOption as an input to the MatlabFunction block, I got this to work in the MatlabFunction block
function x = fcn(nonConOption)
%nonConOption = 1;
%nonlcon = [];
A = [];
b = [];
Aeq = [];
beq = [];
x0 = [1/4,1/4];
fun = @(x)100*(x(2)-x(1)^2)^2 + (1-x(1))^2;
lb = [0,0.2];
ub = [0.5,0.8];
%{
if nonConOption == 1
nonlcon = @circlecon;
else
nonlcon = @(x) deal([],[]);
end
x = fmincon(fun,x0,A,b,Aeq,beq,lb,ub,nonlcon,optimoptions('fmincon','Algorithm','sqp'));
%}
x = fmincon(fun,x0,A,b,Aeq,beq,lb,ub,@(x) foofcn(x,nonConOption),optimoptions('fmincon','Algorithm','sqp'));
end
function [c,ceq] = foofcn(x,nonConOption)
if nonConOption == 1
[c,ceq] = circlecon(x);
else
c = [];
ceq = [];
end
end
function [c,ceq] = circlecon(x)
c = (x(1)-1/3)^2 + (x(2)-1/3)^2 - (1/3)^2;
ceq = [];
end
The commented code worked fine for the case as posted where nonConOption = 1 is hard-coded, but it doesn't build if nonConOption is an input to the function.
I'm actually pleasantly surprised that this code is operable. I'm kind of curious about how the code for foofcn is generated where c is not empty on return from circlecon but is empty otherwise.
更多回答（1 个）
Walter Roberson
2025-3-23
if nonConOption == 1
nonlcon = @circlecon;
else
nonlcon = @(varargin) deal([],[]);
end
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