How often a channel carries a new value
| Tablet | Backend | Firmware | Recordings | Readings / s | Position | Pressure | Pressure hold pattern | Pressure updates / s, if periodic | Pressure values seen | Smallest step |
|---|
Position and Pressure are the share of consecutive in-contact readings that differed from the one before, pooled across the group's recordings in proportion to how many readings each has. Readings / s is the median of the recordings that carry the host clock, each measured over whole strokes; it is an aggregate estimate, and short strokes can bias it. Pressure values seen is the most distinct values any one recording of the group contained: a floor on what the device can report, not the range it has. A dash means the recordings did not carry the column, or had too few completed holds for a pattern to be stated.
Rows are grouped by tablet, backend and firmware as recorded. Driver versions are not a grouping: recordings made on different driver versions of the same tablet and backend are pooled here, so a difference between two rows is not by itself attributable to the driver.
What the hold pattern is, and is not
A hold is how many readings in a row carried the same pressure. Where nearly all completed holds are a multiple of two, pressure is behaving as if it were refreshed every second reading, and a hold of four is then two refreshes that agreed. That is a description of the readings and an inference about the device: equal values cannot tell one measurement reported twice from two measurements that quantized to the same number.
It also cannot say where the pattern comes from. It is in the readings as this recording path delivered them, so it could come from the tablet, its firmware, the driver or the way the driver was read. Telling those apart needs the same pen recorded through more than one of them, which is what a second device or backend is for.
Each recording's own page shows the same measurements with the length of every hold. The method is in FORMAT.md.