Choice → Coordinates — Python tools UI (web-based)

Fit an MDS perceptual map from a choice file and download the result as a coordinates .mat file — no installation required to use the hosted version below.

Live app

App	URL	File
Choice → Coordinates	choicetocoord.streamlit.app	run_model_fitting_ui.py

Note: the app may be asleep if inactive — click the link and wait a moment for it to wake up. The hosted version runs on limited, shared resources — best for small datasets and a quick look, not a final fit.

Running locally

Faster than the hosted version, and not limited by its shared resources:

cd rs-software
pip install streamlit plotly pandas matplotlib scikit-learn
streamlit run run_model_fitting_ui.py

Then open http://localhost:8501 in your browser.

How to use

1. Upload a .mat choice file
2. Set dimension range, max iterations, and random seed mode
3. Click Run MDS

Output .mat fields:

Field	Size	Description
dim1...dimN	n_stim × N	Coordinates for each fitted dimension
rawLLs	1 × N	Raw log-likelihood for each model
bestModelLL	1 × 1	Log-likelihood of best possible model
randModelLL	1 × 1	Log-likelihood of random-choice model
biasEstimate	1 × N	Median bias estimate per dimension
debiasedRelativeLL	1 × N	rawLLs + biasEstimate - bestModelLL
stim_labels	n_stim	Stimulus names (coords files use stim_labels; choice files use stim_list)

Random seed: choose "Random each run" for normal use, or "Same every run" / "Custom random seed" for a reproducible result — useful when checking output against a benchmark.

For the equivalent Python functions, see Choice → Coordinates → Python.