# densCols

##### Colors for Smooth Density Plots

`densCols`

produces a vector containing colors which encode the
local densities at each point in a scatterplot.

- Keywords
- dplot

##### Usage

```
densCols(x, y = NULL, nbin = 128, bandwidth,
colramp = colorRampPalette(blues9[-(1:3)]))
blues9
```

##### Arguments

- x, y
the

`x`

and`y`

arguments provide the x and y coordinates of the points. Any reasonable way of defining the coordinates is acceptable. See the function`xy.coords`

for details. If supplied separately, they must be of the same length.- nbin
numeric vector of length one (for both directions) or two (for x and y separately) specifying the number of equally spaced grid points for the density estimation; directly used as

`gridsize`

in`bkde2D()`

.- bandwidth
numeric vector (length 1 or 2) of smoothing bandwidth(s). If missing, a more or less useful default is used.

`bandwidth`

is subsequently passed to function`bkde2D`

.- colramp
function accepting an integer

`n`

as an argument and returning`n`

colors.

##### Details

`densCols`

computes and returns the set of colors that will be
used in plotting, calling ```
bkde2D(*,
bandwidth, gridsize = nbin, ..)
```

from package KernSmooth.

`blues9`

is a set of 9 color shades of blue used as the default in
plotting.

##### Value

`densCols`

returns a vector of length `nrow(x)`

that
contains colors to be used in a subsequent scatterplot. Each color
represents the local density around the corresponding point.

##### See Also

`bkde2D`

from package KernSmooth;
further, `smoothScatter()`

(package graphics) which
builds on the same computations as `densCols`

.

##### Examples

`library(grDevices)`

```
# NOT RUN {
x1 <- matrix(rnorm(1e3), ncol = 2)
x2 <- matrix(rnorm(1e3, mean = 3, sd = 1.5), ncol = 2)
x <- rbind(x1, x2)
dcols <- densCols(x)
graphics::plot(x, col = dcols, pch = 20, main = "n = 1000")
# }
```

*Documentation reproduced from package grDevices, version 3.6.0, License: Part of R 3.6.0*