Explain Analysis time with a worked example, in the interface and the user guide

[apetros]

Reported by Thierry Van Cutsem, 2026-08-18: "What is the analysis time ??"

Nothing on screen explains it. The only explanation is the tooltip on src/my/stepss/StepssUI.java:2341, and a tooltip is not where someone looks when a field is unfamiliar.

What it means

SsaDisturbance.MIN_TIME is 0.001 s and is the default: it linearises the initial operating point as given. A later t runs an event free simulation up to that time and linearises the point reached there.

Fix

Put a worked example beside the field, not just a definition, and the same in stepss-docs user-guide/eigenanalysis.md. Something along these lines:

0.001 analyses the initial operating point as given. 10 runs a 10 s simulation with no disturbances first and analyses the point reached there, which is what you want when the model does not initialise cleanly and needs a moment to settle.

That last clause is the part users actually need, and it is currently written down nowhere.