[ 机器学习 - 吴恩达 ] Linear regression with one variable | 2-1 Model representation


Housing Prices

  • Supervised Learning: Given the "right answer" for each example in the data
  • Regression Problem: Predict real-valed (实数) output

Training set of housing prices (Portland, OR)

Size in \(feet^2\) (x) Price ($) in 1000's (y)
2104 460
1416 232
1534 315
852 178

Notation:

  • m = Number of training examples
  • x's = "input" variable / features
  • y's = "output" variable / "target" variable
  • (x, y) - one training example
  • (\(x^(i)\), \(y^(i)\)) - \(i^{th}\) traning example

"h: hypothesis (假设)" maps from x's to y's

How do we represent \(h\)? (在房价数据集上)

\[h_\theta = \theta_0 + \theta_1x \]

Shorthand: \(h(x)\)
"Linear regression with one variable. \(x\)"
or "Univariable linear regression."