Guo_danyang的博客

Simple example: ORx1,x2∈x_1, x_2 \inx1​,x2​∈{0, 1}y=x1ORx2y = x_1 OR x_2y=x1​ORx2​hθ(x)=g(−10+20x1+20x2)h_\theta(x) = g(-10 + 20x_1+20x_2)hθ​(x)=g(−10+20x1​+20x2​)g(x)=11+e−xg(x) = \frac1{1+e^{-x}}g(x)=1+e−x1​x1x_1x1​x2x_2x2​hθ(x)h_{\theta}(x)h

Simple example: ANDx1,x2∈x_1, x_2 \inx1​,x2​∈{1, 2}y=x1ANDx2y = x_1 AND x_2y=x1​ANDx2​hθ(x)=g(−30+20x1+20x2)h_\theta(x) = g(-30 + 20x_1+20x_2)hθ​(x)=g(−30+20x1​+20x2​)激活函数：g(x)=11+e−xg(x) = \frac1{1+e^{-x}}g(x)=1+e−x1​x1x_1x1​x2x_2x2​hθ(x)h_{

吴恩达机器学习课后作业 Linear Regression损失函数12mΣi=1m(h(x)−y)2\frac{1}{2m}\Sigma_{i=1}^m(h(x) -y)^22m1​Σi=1m​(h(x)−y)2其中：h(x)=θ1∗x+θ0h(x) = \theta_1*x + \theta_0h(x)=θ1​∗x+θ0​m：代表训练样本实例的个数x, y都来来源于数据集，对应的意义x代表房屋的面积，y代表房屋的价格。目标是求两个参数θ0,θ1\theta_0,\theta_1θ0​,θ1​