shinySim is a point-and-click interface to the squidSim package. It lets you build structured simulations — hierarchical data structures, predictors, and variance components across levels — without writing the simulation call by hand.
Simulating structured data is something most people do rarely and under time
pressure: checking whether a design has the power to detect an effect, generating
a dataset to test an analysis pipeline, or teaching where variance actually sits
in a mixed model. The syntax is the barrier, not the concept. shinySim moves that
work into a UI, shows the variance decomposition as you build it, and hands back
both the simulated dataset and the equivalent squidSim code — so the app is a
way in, not a dependency.
- Build a data structure interactively. Define nested and crossed levels, sample sizes, and repeat observations, or pass in a structure you already have.
- Set variance components per level. Specify predictors, betas, and (co)variances for each grouping factor.
- See the equations as you go. The app writes out the model being simulated, so what you are building stays legible.
- Inspect simulated variances. Check that the realised variance components match what you asked for before you commit to a design.
- Get the code back. The equivalent
squidSimcall is returned alongside the data, so simulations remain reproducible outside the app. - Runs locally. Nothing is uploaded anywhere.
shinySim is not on CRAN, but you can install the development version from GitHub using the devtools package:
install.packages("devtools")
devtools::install_github("squidgroup/shinySim")
library(shinySim)This will also install squidSim, which
is not on CRAN and is declared via Remotes:.
The only function is shinySim(). It can be run without any arguments:
library(shinySim)
shinySim()Or you can provide a data structure created in squidSim (or elsewhere):
library(shinySim)
data_test <- squidSim::make_structure(
"sex(2)/individual(10)",
repeat_obs = 2,
level_names = list(sex = c("F", "M"))
)
shinySim(data.struc = data_test)| Argument | Purpose |
|---|---|
data.struc |
A data structure created with squidSim::make_structure() or an equivalent data frame. Optional — leave empty to build one in the app. |
Please file issues and feature requests at https://github.com/squidgroup/shinySim/issues. Pull requests are welcome.
Issues with the underlying simulation engine belong upstream at squidgroup/squidSim.
- squidSim — the simulation engine this app drives
- SQuID — the Statistical Quantification of Individual Differences group
Please cite the package (adjust the year as needed):
Ivimey-Cook, E. R., & Pick, J. L. (2026). shinySim: Shiny interface to the squidSim simulation package. R package version 0.0.0.9000. https://github.com/squidgroup/shinySim
A machine-readable CITATION.cff is included, so GitHub's
"Cite this repository" button gives formatted APA and BibTeX.
Released under the MIT License.