machine learning (2)

machine learning (2)

Linear regression with one variable = univariate linear regression: 由一个输入变量预测出一个output (regression problem预测连续的值). single input<--->single output
univariate linear regression = Linear regression with one variable
The Hypothesis Function: ,一个假设的函数（求出假设的 θ0 和 θ1，这个是我们的目标,愈近的接近真实的y值）,这样可以根据input value(x)来计算output value(y)
Cost Function: (y为真实的值),用来衡量假设函数（hypothesis function）的准确性,
Squared error function = cost function
Mean squared error = cost function
Gradient Descent: 一种用来自动提高hypothesis function准确性的方法
learning rate: ,朝着cost function的导数方向以a系数倍数逼近真值。
The gradient descent equation: (j=0,1)
Gradient Descent for Linear Regression:

时间： 2024-10-29 19:10:33

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