1. Nonpapametric Smoothing (1)
Consider X Y plot.
Draw a regression line which requires no parametric assu mptions
The regression line is not linear
The regression line is totally dependent on the data
Two components of smoothing
Kernal function : How to calculate weighted mean
Bandwidth : width of the window (span), determines the s moothness of the regression line; wider > smoother

2. Nonpapametric Smoothing (2)
Uniform Kernel

3. Nonpapametric Smoothing (3)
Triangular Kernel

4. Nonpapametric Smoothing (4)
Normal Kernel

5. Nonpapametric Smoothing (5)
Default Lowess line : Span=0.5

6. Nonpapametric Smoothing (6)
Lowess line : Span=0.2

7. Nonpapametric Smoothing (7)
Lowess line : Span=0.1

8. Spline

10. Df를 늘리면 더 smooth 해짐!