


# ellipse



[![R-CMD-check](https://github.com/dmurdoch/ellipse/actions/workflows/R-CMD-check.yaml/badge.svg)](https://github.com/dmurdoch/ellipse/actions/workflows/R-CMD-check.yaml)
[![CRAN
status](https://www.r-pkg.org/badges/version/ellipse)](https://CRAN.R-project.org/package=ellipse)


`ellipse` contains ellipse drawing routines designed for pairwise
confidence regions, including distorted ellipses for nonlinear
regression regions. It also includes a routine `plotcorr()` for plotting
correlation matrices using ellipses.

## Installation

It is on CRAN, and can be installed using

``` r
install.packages("ellipse")
```

You can install the development version of ellipse from
[GitHub](https://github.com/) with:

``` r
# install.packages("devtools")
devtools::install_github("dmurdoch/ellipse")
```

## Example

Plot approximate pairwise confidence regions and profile trace plots for
a nonlinear fit:

``` r
data(Puromycin)
Purboth <- nls(formula = rate ~ ((Vm + delV * (state == "treated"))
   * conc)/(K + conc), data = Puromycin,
   start = list(Vm = 160, delV = 40, K = 0.05))
Pur.prof <- profile(Purboth)
ellipse::pairs(Pur.prof)
```


The `plotcorr()` function can plot a matrix of ellipses:

``` r
library(ellipse)
#> 
#> Attaching package: 'ellipse'
#> The following object is masked from 'package:graphics':
#> 
#>     pairs
corr.mtcars <- cor(mtcars)
ord <- order(corr.mtcars[1,])
xc <- corr.mtcars[ord, ord]
colors <- c("#A50F15","#DE2D26","#FB6A4A","#FCAE91","#FEE5D9","white",
            "#EFF3FF","#BDD7E7","#6BAED6","#3182BD","#08519C")   
plotcorr(xc, col=colors[5*xc + 6])
```


