A reciprocal bin step maps each detector bin index to a reciprocal-space value by multiplying the index by a fixed step, so equally spaced bins cover equally spaced positions. With training step 2 per meter, bin indices 0, 1, 2, and 3 give values 0, 2, 4, and 6 exactly for the stated one-dimensional toy map; real reciprocal-space maps need calibration, finite bin width, geometry correction, peak spread, and measurement uncertainty.
A simplified detector map can use exact reciprocal-space training bins. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
A reciprocal bin has a checked step
The training reciprocal step is 2 per metre.
Δq=21/m
Index times step gives bin value
The four checked bin values are 0 per metre, 2 per metre, 4 per metre, and 6 per metre. This is a one-dimensional training map, not full crystallographic indexing.