Byte-Table Scaling: Percentages, Offsets and Clamping
This lesson applies documented arithmetic to supplied unsigned decimal byte values; it does not teach ECU tuning.
Two operations on supplied values
The Map Scale Adjuster accepts rows of unsigned decimal integers from 0 through 255. Percentage mode multiplies by a finite, non-negative percentage; offset mode adds a finite amount, including negative or fractional offsets. Both operations calculate first, round to the nearest whole number, then clamp to 0–255.
Calculate, round, then clamp
One synthetic byte value follows the Map Scale Adjuster's operation order.
- Input
Synthetic unsigned byte
240 at 110%
- Calculate: 240 × 1.10 = 264
- Round: 264
- Clamp to 0–255
- Byte result
255
Clamped to the maximum byte value
Text equivalent
Start with the synthetic unsigned byte 240 and apply 110 percent. Calculate 240 times 1.10 to get 264, round to the nearest whole number (still 264), then clamp to the byte maximum 255. The output is 255 and is marked clamped.
For a rounding-only case, 41 × 1.10 = 45.1, then rounds to 45. At the lower edge, 3 + (−5) = −2, then clamps to 0. An unchanged value stays the same; an in-range changed value is transformed.
What this operation does not say
The tool transforms cells independently. It does not interpret multi-byte words, signed encodings, byte order, axes, units or ECU-specific scaling metadata. It does not discover map boundaries or establish whether any change is appropriate for a vehicle. A clean-looking result is still only arithmetic on user-supplied data.
For the surrounding workflow, first learn how to shape selected bytes into a bounded table in Creating and Inspecting Synthetic Byte Tables. Once you have worked the calculation by hand, enter the same decimal table and setting in the Map Scale Adjuster to compare the output.
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