computeCost.m 748 B

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  1. function J = computeCost(X, y, theta)
  2. %COMPUTECOST Compute cost for linear regression
  3. % J = COMPUTECOST(X, y, theta) computes the cost of using theta as the
  4. % parameter for linear regression to fit the data points in X and y
  5. % Initialize some useful values
  6. m = length(y); % number of training examples
  7. % You need to return the following variables correctly
  8. % J = 0;
  9. % for i = 1:m
  10. % J = J + (theta' * X(i,:)' - y(i)) ^ 2
  11. % end
  12. % J = J / m / 2
  13. z = (X*theta-y);
  14. J = z' * z / 2 / m;
  15. % ====================== YOUR CODE HERE ======================
  16. % Instructions: Compute the cost of a particular choice of theta
  17. % You should set J to the cost.
  18. % =========================================================================
  19. end