I'm using R version 4.04.

```
install.packages('nls')
Installing package into ‘/home/gpc/R/x86_64-pc-linux-gnu-library/4.0’
(as ‘lib’ is unspecified)
Warning in install.packages :
package ‘nls’ is not available for this version of R
A version of this package for your version of R might be available elsewhere,
see the ideas at
https://cran.r-project.org/doc/manuals/r-patched/R-admin.html#Installing-packages
```

I'm working through some basic exercises in a textbook here ('Try it #3, just over a 3rd of the way down').

The data frame is provided:

```
ti3_df <- data.frame(
x = 0:15,
y = c(3.493, 5.282, 6.357, 9.201, 11.224, 12.964, 16.226, 18.137,
19.590, 21.955, 22.862, 23.869, 24.243, 24.344, 24.919, 25.108)
)
```

Along with the question:

Use logistic regression to fit a model to these data.

Apparently the wording here is not great, and folk over on stats.stackexchange prefer the term 'logistic growth' or 'sigmoid growth curve' over logistic regression for this context.

The linked solutions over there reference the nls package e.g.

```
nls(density ~ SSlogis(log(conc), Asym, xmid, scal),+ DNase1)
```

But per the above, I'm unable to install this nls package.

Are there any alternative solutions in R for fitting a logistic-growth-curve outside of nls package?