Problem with Gradient descent
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Hello,
I am currently following the programm of Machine Learning and I have a problem with the first assignment since 2 months.
When I try to plot the gradient descent: Matlab send me this error:
gradientDescent
Not enough input arguments.
Error in gradientDescent (line 7)
m = length(y); % number of training examples
This is my code :
function [theta, J_history,theta_history] = gradientDescent(X, y, theta, alpha, num_iters)
%GRADIENTDESCENT Performs gradient descent to learn theta
% theta = GRADIENTDESCENT(X, y, theta, alpha, num_iters) updates theta by
% taking num_iters gradient steps with learning rate alpha
% Initialize some useful values
m = length(y); % number of training examples
J_history = zeros(num_iters, 1);
for iter = 1:num_iters
% ====================== YOUR CODE HERE ======================
% Instructions: Perform a single gradient step on the parameter vector
% theta.
%
% Hint: While debugging, it can be useful to print out the values
% of the cost function (computeCost) and gradient here.
%
error=(X.*theta-y)
temp0=theta(1)+(alpha/m)*sum(error.*X(:,1));
temp1=theta(2)+(alpha/m)*sum(error.*X(:,2));
theta=[temp0,temp1]
% ============================================================
% Save the cost J in every iteration
J_history(iter) = computeCost(X, y, theta);
end
end
Thanks in advance for your help
8 Comments
Walter Roberson
on 25 Apr 2021
X, y are supposed to be passed into the function.
We have no information as to how m is defined.
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