ksmooth
Kernel Regression Smoother

### Description

Performs scatterplot smoothing using kernel estimates.

### Usage

    ksmooth(x, y, kernel = c("box", "normal"), bandwidth = 0.5,
        range.x = range(x), n.points = max(100, length(x)), x.points)

### Arguments

x | a vector of x data. Missing values (NAs) are not accepted.
y | a vector of y data. This must be same length as x, and missing values (NAs) are not accepted.
kernel | a character string that determines the smoothing kernel. kernel can be one of the following.
| "box" | a rectangular box (the default).
| "normal" | the gaussian density function.
bandwidth | the kernel bandwidth smoothing parameter. All kernels are scaled so the upper and lower quartiles of the kernel (viewed as a probability density) are +/- 0.25. Larger values of bandwidth make smoother estimates; smaller values of bandwidth make less smooth estimates.
range.x | a vector containing the minimum and maximum values of x at which to compute the estimate. If not specified, this argument is set to range(x).
n.points | the number of points to smooth in the interval range.x. n.points is set to the length of x.point if x.points is supplied.
x.points | a vector specifying where the kernel estimate is computed. If this argument is not specified, it is set to seq.int(range.x[1], range.x[2], length=n.points).

Value
returns a list containing the following components:

x | a vector of sorted x values at which the kernel estimate was computed.
y | a vector of smoothed estimates for the regression at the corresponding x.

References
Silverman, B. W. 1986. Density Estimation for Statistics and Data Analysis. London, UK: Chapman and Hall.
Watson, G. S. 1966. Smooth regression analysis. Sankha, Ser. A. Volume 26. 359-378.
See Also
density, loess, smooth, supsmu
Examples

    # Make up some data:
    set.seed(50)
    x <- rnorm(100)
    eps <- rnorm(100, 0, .1)
    y <- sin(x) + eps
    # A kernel regression estimate for y on x.
    ksmxy <- ksmooth(x, y, kern="normal", band=.5, n=50)

Package stats version 6.1.5-18
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