Running a simulation
The difference between the preview that follows your edits and the run you save, and why Run is sometimes disabled.
A simulation samples the whole map many times over, drawing a value from each node's uncertainty each pass, and reports what came out.
Two things do this: previews and runs.
Previews follow your edits
As you edit, Radiant re-simulates in the background and updates the values on every node. This is the preview.
- It is never saved.
- It stays stable while you work, so values do not change for reasons unrelated to your edits.
Previews run whenever any node can be evaluated. A map with errors can still show values on unaffected nodes; a blocked node shows no result.
Runs are deliberate and saved
Run simulation, in the toolbar or R, performs a full simulation and saves the answer.
A saved run keeps its result and a snapshot of the map as it was when you pressed the button. Reopening it later shows that map read-only, so you can return to the assumptions behind the result.
Everyone sees a stored run
When one person saves a run, other collaborators can see it in the run history.
Why Run can be disabled
Run is disabled when the map's primary output is blocked, and the button names the reason.
This is deliberate, and it is the one place where previews and runs are treated differently. A preview is a working aid, so it shows whatever it can. A stored run states the model's answer, and it should not be possible to save one built over a gap.
If Run is disabled, the fix is in the diagnostics — see Troubleshooting forecasts.
Runs and the assistant
The assistant can run a simulation to answer a question about the map. Those results are not saved to your run history; the list contains only runs you deliberately kept.
After you save a run, Radiant may add a short title and summary to help identify it later.
Where runs go
Saved runs appear in the run history. Opening one swaps the map for a read-only view of the frozen copy; leaving puts your live map back untouched.