Description
Functions for Drawing Ellipses and Ellipse-Like Confidence Regions.
Description
Contains various routines for drawing ellipses and ellipse-like confidence regions, implementing the plots described in Murdoch and Chow (1996, <doi:10.2307/2684435>). There are also routines implementing the profile plots described in Bates and Watts (1988, <doi:10.1002/9780470316757>).
README.md
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
install.packages("ellipse")
You can install the development version of ellipse from GitHub with:
# install.packages("devtools")
devtools::install_github("dmurdoch/ellipse")
Example
Plot approximate pairwise confidence regions and profile trace plots for a nonlinear fit:
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:
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])
