Validation

Checking that a sequence plays as it was written: the gradients it asks for against a recording of a machine playing it, or against the waveforms its own cache holds.

The two comparisons answer different questions. A recording establishes that the machine plays the sequence, end to end through the conversion, the interpreter and the hardware. The cache establishes only that the conversion kept the sequence: a conversion and a playout that are wrong in the same way agree with each other. reference says which was answered, and the command prints it.

A machine drives its transmit and its gradient channels on separate timelines and records each as it drove it, so the two are offset in a recording by that machine’s own constant. shift_us states it. Nothing here estimates it: a comparison that quietly aligns two waveforms can align away the disagreement it exists to find.

Object	Description
validate	Check a sequence against a recording of it, or against its own cache.
Comparison	What a comparison established, and what it compared against.
ChannelAgreement	How far apart one channel’s two renderings are.
gradient_tolerance_mt_per_m	Gradient tolerance, in mT/m, from the slew rate over three gradient raster steps.
read_waveform_xml	Read the waveform XML a scanner’s plotter writes.
PlayedWaveforms	What a scanner played, as its plotter recorded it.
VENDORS	The machines a recording can be read from.