# Shade

From DescTools v0.99.19
by Andri Signorell

##### Produce a Shaded Curve

Sometimes the area under a density on a graphic has to be color shaded, for instance to illustrate a p-value or a region under the normal curve. This function offers a function interface for doing this with less code.

- Keywords
- aplot

##### Usage

`Shade(FUN, col = par("fg"), xlim, density = 10, step = 0.01, ...)`

##### Arguments

- FUN
- the function to be evaluated, best given as text:
`FUN="f(x)"`

. - col
- color to fill or shade the shape with. The default is taken from
`par("fg")`

. - xlim
- range of the x-range.
- density
- the density of the lines as needed in polygon.
- step
- the step for the x-values to be used for calculating the function values.
- ...
- the dots are passed on to
`polygon`

.

##### Details

Useful for shading the area under a curve as often needed for explaining significance tests.

##### Value

##### See Also

##### Examples

```
curve(dt(x, df=5), xlim=c(-6,6),
main=paste("Student t-Distribution Probability Density Function, df = ", 5, ")", sep=""),
type="n", las=1, ylab="probability", xlab="t")
Shade(FUN="dt(x, df=5)", xlim=c(-6, qt(0.025, df=5)), col="red")
Shade(FUN="dt(x, df=5)", xlim=c(qt(0.025, df=5), qt(0.975, df=5)), col="green")
Shade(FUN="dt(x, df=5)", xlim=c(qt(0.975, df=5), 6), col="red")
```

*Documentation reproduced from package DescTools, version 0.99.19, License: GPL (>= 2)*

### Community examples

Looks like there are no examples yet.