R: Smoothed Densities X with Y

SmoothedDensitiesXY {DataVisualizations} | R Documentation

## Smoothed Densities X with Y

### Description

Density is the smothed histogram density at [X,Y] of [Eilers/Goeman, 2004]

### Usage

    SmoothedDensitiesXY(X, Y, nbins, lambda, Xkernels, Ykernels, PlotIt = FALSE)

### Arguments

`X` | Numeric vector [1:n], first feature (for x axis values)
`Y` | Numeric vector [1:n], second feature (for y axis values), nbins= nxy => the nr of bins in x and y is nxy nbins = c(nx,ny) => the nr of bins in x is nx and for y is ny
`nbins` | number of bins, nbins =200 (default)
`lambda` | smoothing factor used by the density estimator or c() default: lambda = 20 which roughly means that the smoothing is over 20 bins around a given point.
`Xkernels` | bin kernels in x direction are given
`Ykernels` | bin kernels y direction are given
`PlotIt` | FALSE: no plotting, TRUE: simple plot

### Details

lambda has to chosen by the user and is a sensitive parameter.

### Value

List of:

`Densities` | numeric vector [1:n] is the smothed density in 3D
`Xkernels` | numeric vector [1:nx], nx defined by `nbins`, such that mesh(Xkernels,Ykernels,F) form the ( not NaN) smothed densisties
`Ykernels` | numeric vector [1:ny], nx defined by `nbins`, such that mesh(Xkernels,Ykernels,F) form the ( not NaN) smothed densisties
`hist_F_2D` | matrix [1:nx,1:ny] beeing the smoothed 2D histogram
`ind` | an index such that `Densities = hist_F_2D[ind]`

### Author(s)

Michael Thrun, reimplemented from Matlab (Alfred Ultsch)

### References

[Eilers/Goeman, 2004] Eilers, P. H., & Goeman, J. J.: Enhancing scatterplots with smoothed densities, Bioinformatics, Vol. 20(5), pp. 623-628. 2004.

### See Also

`DensityScatter`

### Examples

    data("ITS")
    data("MTY")
    Inds=which(ITS<900&MTY<8000)
    V=SmoothedDensitiesXY(ITS[Inds],MTY[Inds])

[Package DataVisualizations version 1.2.3 Index]