quantize_readout_timing

pypulseqpp.quantize_readout_timing()

Choose an ADC dwell from a requested receiver bandwidth.

Receiver bandwidth is the full sampling bandwidth, 1 / dwell in Hz, not bandwidth per pixel.

Search upward from the nearest ADC-raster dwell satisfying the duration floor, for at most MAX_RASTER_SEARCH_STEPS candidates. If none aligns the readout to the gradient raster, return that starting dwell. Inputs must have positive sample count, bandwidth and rasters.

Parameters:

• nx_ro (int) – Number of readout samples.

• target_bw_hz_px (float) – Requested receiver bandwidth in Hz, i.e. 1 / dwell. The parameter name is kept for compatibility; the value is not a per-pixel bandwidth.

• grad_raster_s (float) – Gradient and ADC rasters (s).

• adc_raster_s (float) – Gradient and ADC rasters (s).

• min_flat_time_s (float) – Lower bound on the flat time (s), e.g. from the max-gradient limit.

Returns:

• dwell_s (float) – ADC dwell time (s), a multiple of adc_raster_s.

• flat_time_s (float) – nx_ro * dwell_s (s); gradient-raster alignment is not guaranteed if the search is exhausted.

Examples

>>> from pypulseqpp._timing import quantize_readout_timing
>>> dwell, flat = quantize_readout_timing(256, 62_500.0, 1e-5, 1e-7, 0.0)
>>> abs(flat / 1e-5 - round(flat / 1e-5)) < 1e-9
True