df: r6 octave

ds/25-1/r/6/mlclass-ex1/computeCost.m

@@ -0,0 +1,26 @@
+function J = computeCost(X, y, theta)
+%COMPUTECOST Compute cost for linear regression
+%   J = COMPUTECOST(X, y, theta) computes the cost of using theta as the
+%   parameter for linear regression to fit the data points in X and y
+
+% Initialize some useful values
+m = length(y); % number of training examples
+
+% You need to return the following variables correctly
+J = 0;
+
+% ====================== YOUR CODE HERE ======================
+% Instructions: Compute the cost of a particular choice of theta
+%               You should set J to the cost.
+% X: (m, 2)
+% y: (m, 1)
+% theta: (2, 1)
+
+h = X * theta;
+dif = h - y;
+sqdif = dif .^ 2;
+J = 1 / (2 * m) * sum(sqdif);
+
+% =========================================================================
+
+end