mech_resonance_spectrum

pypulseqpp.safety.mech_resonance_spectrum()

Return the gradient amplitude spectrum of one window, per physical axis.

The window is taken, tapered and transformed by check_mech_resonance()’s own pass, so a diagram of a band and the verdict on it read the same numbers.

Parameters:

• seq (Sequence) – Sequence to read.

• window (int, default=0) – Which window, counted from zero. A report names the worst window of each band as window.

• window_width (float, default=0.04) – Window length (s). Give the width the report was made with.

• stride (float, default=None) – Step between window starts (s); half the width by default.

• frequency_oversampling (int, default=3) – Transform length as a multiple of the window’s sample count.

• rotation (array_like, default=None) – 3x3 prescription rotation from logical to physical axes.

• system (pypulseqpp.Opts, default=None) – Source of the gyromagnetic ratio; the sequence’s own by default.

Returns:

frequency (Hz), one per bin; amplitude, (3, bins) in mT/m for x, y and z; axes, the names in that order; window, window_start (s), window_width (s) and frequency_step (Hz).

Return type:

SimpleNamespace

Raises:

ValueError – If a width, stride or oversampling is out of range, or the sequence has no window of that index.