MATLAB Answers

Error: Undefined function <func_name> for input arguments of type 'double'.

Below is a small part of the big code, Where I'm getting an error at line 3. Undefined function 'f1' for input arguments of type 'double'.
Below I've changed the code little bit as compared to the source to make it more readable.
function fit = dummy(x)
fhd = str2func('f1');
fit = feval(fhd, x); % Error Here
%------------------------------------------------------------------------------
% Elliptic Function
%------------------------------------------------------------------------------
function fit = elliptic(x)
%TODO Do we need symmetry breaking?
%TODO Implement to support a matrix as input.
[D ps] = size(x);
condition = 1e+6;
coefficients = condition .^ linspace(0, 1, D);
fit = coefficients * T_irreg(x).^2;
end
function fit = f1(x)
persistent xopt lb ub
[D ps] = size(x);
load 'datafiles/f01.mat';
idx = checkBounds(x, lb, ub);
x = x-repmat(xopt, 1, ps);
fit = elliptic(x);
fit(idx) = NaN;
if ~isempty(idx)
warning "Some of the solutions are violating boundary constraints.";
end
end
end
Please help me to sort out the problem. For the complete code checkout "benchmark_func.m" in the "matlab.zip" attached.

  댓글 수: 0

로그인 to comment.

답변 수: 2

Guillaume 님의 답변 10 Feb 2017
 채택된 답변

I suspect the problem is str2func not seeing the local function. That's the problem with using strings to store code, the JIT compiler doesn't always work properly.
Any reason you're using an outdated method of creating and using function handles?
fhd = @f1;
fit = fhd(x);
would work, is simpler and possibly faster as well.
If f1 is one of many possibilities to be chosen by that dummy function:
fchoices = {@f1, @f2, @f3};
fhd = fchoices{choice};
fit = fhd(x);

  댓글 수: 1

+1 for recommending function handles (much better than awful strings).

로그인 to comment.


Massimo Zanetti 님의 답변 10 Feb 2017
Massimo Zanetti 님이 편집함. 10 Feb 2017

Refer to your 2nd line of code
fhd = str2func('f1');
The string 'f1' evaluates to nothing in Matlab, therefore the command
fit = feval(fhd, x);
fails. To let it work, 'f1' must be an anounimous function definition. Read str2func help page.

  댓글 수: 0

로그인 to comment.



Translated by