hsv {grDevices} R Documentation

## HSV Color Specification

### Description

Create a vector of colors from vectors specifying hue, saturation and value.

### Usage

```hsv(h = 1, s = 1, v = 1, gamma = 1, alpha)
```

### Arguments

 `h,s,v` numeric vectors of values in the range `[0,1]` for “hue”, “saturation” and “value” to be combined to form a vector of colors. Values in shorter arguments are recycled. `gamma` a “gamma correction” exponent, gamma `alpha` numeric vector of values in the range `[0,1]` for alpha transparency channel (0 means transparent and 1 means opaque).

### Details

Semi-transparent colors (`0 < alpha < 1`) are supported only on a few devices: at the time of writing only on the `pdf` and (on MacOS X) `quartz` devices.

### Value

This function creates a vector of “colors” corresponding to the given values in HSV space. The values returned by `hsv` can be used with a `col=` specification in graphics functions or in `par`.

### Gamma correction

For each color, (r,g,b) in RGB space (with all values in [0,1]), the final color corresponds to (r^{gamma}, g^{gamma}, b^{gamma}).

### See Also

`hcl` for a perceptually based version of `hsv()`, `rgb` and `rgb2hsv` for RGB to HSV conversion; `rainbow`, `gray`.

### Examples

```hsv(.5,.5,.5)

## Look at gamma effect:
n <- 20;  y <- -sin(3*pi*((1:n)-1/2)/n)
op <- par(mfrow=c(3,2),mar=rep(1.5,4))
for(gamma in c(.4, .6, .8, 1, 1.2, 1.5))
plot(y, axes = FALSE, frame.plot = TRUE,
xlab = "", ylab = "", pch = 21, cex = 30,
bg = rainbow(n, start=.85, end=.1, gamma = gamma),
main = paste("Red tones;  gamma=",format(gamma)))
par(op)
```

[Package grDevices version 2.5.0 Index]