Undefined function 'sigmoid' for input arguments of type 'double'.
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addpath('C:\Program Files\MATLAB\R2012a\Matlab\q2')
load X.dat
load Y.dat
temp1=X(:,1);
temp2=X(:,2);
temp1=(temp1-mean(temp1))./std(temp1);
temp2=(temp2-mean(temp2))./std(temp2);
m=length(X);
X=[ones(m,1),temp1,temp2];
theta=[0;0;0];
MAX_ITR=100;
J=zeros(MAX_ITR,1);
alpha=0.07;
for num_iteration=1:MAX_ITR
J(num_iteration)=(1/m)*((-Y')*log(sigmoid(X*theta))-(1-Y')*log(1-sigmoid(X*theta)));
grad=(1/m)*X'*(sigmoid(X*theta)-Y);
theta=theta-alpha.*grad;
end
z=X*theta;
g=inline('(1./(1+exp(-z)))');
fprintf('Theta values are ...\n')
g(z)
Undefined function 'sigmoid' for input arguments of type 'double'.
回答（1 个）
Guillaume
2014-10-22
0 个投票
As far as I can tell, sigmoid is not a function of matlab in any toolbox, so unless you've written it yourself and it's in the matlab path, it's not going to be found.
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