# Beta.gfx.poly.qdf

##### Coordinate Generation for Marking an Area Under the Curve for the Beta Quantile Density Distribution.

Plotting tool, producing a two-column matrix with values of `y`

corresponding to locations on `x`

. Useful for shading areas under the curve when tracing the line for the Standard Beta probability quantile function.

##### Usage

`Beta.gfx.poly.qdf(from, to, by, alpha, beta, l = 0, u = 1)`

##### Arguments

- from
The point of the

`x`

-axis from where to start producing`y`

-quantile values.- to
The point of the

`x`

-axis to where`y`

-quantile values are to be produced.- by
The resolution (or spacing) at which to produce

`y`

-density values.- alpha
The Alpha shape-parameter value for the Standard Beta probability distribution.

- beta
The Beta shape-parameter for the Standard Beta probability distribution.

- l
The lower-bound location parameter of the Beta distribution.

- u
The upper-bound location parameter of the Beta distribution.

##### Value

A two-column matrix with quantile-values of `y`

to plot against corresponding location values of `x`

.

##### Examples

```
# NOT RUN {
# To box in an area under a four-parameter beta quantile distribution with
# location parameters l = .25 and u = 75, and shape parameters
# alpha = 5 and beta = 3, from .4 to .6:
plot(NULL, xlim = c(0, 1), ylim = c(0, 1))
coords <- Beta.gfx.poly.qdf(from = .4, to = .6, by = .001, alpha = 5,
beta = 3, l = .25, u = .75)
polygon(coords)
# }
```

*Documentation reproduced from package betafunctions, version 1.4.0, License: CC0*