plot_rf

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plot_rf#

pypulseqpp.plot.plot_rf()[source]#

Draw an RF pulse’s |B1| envelope beside the profile it produces.

Parameters:

  • source (Sequence, sequence module or RF event) – Source of the RF event. From a sequence, only the pulse’s own block is simulated unless a range is given.

  • pulse (RF event or str, default=None) – Which pulse of source: an event, or the use it is tagged with ("refocusing" finds a spin echo’s refocusing pulse). The first pulse by default.

  • time_range (sequence, default=None) – Blocks of a sequence to simulate over, where the profile needs more than the pulse’s own block.

  • block_range (sequence, default=None) – Blocks of a sequence to simulate over, where the profile needs more than the pulse’s own block.

  • plane (str, default=None) – One of x, y, z and f (off-resonance) for a profile, or two for a plane drawn as |Mxy| and Mz heatmaps. By default the axis the pulse is selective along, or f without a gradient.

  • kind ({"excitation", "refocusing", "inversion", "saturation"}, default=None) – Which response a profile draws; the pulse’s use by default.

  • extent (float or pair of float, default=None) – Limits of the first and second axis: a half-width about zero or a (low, high) pair, in mm for a position and Hz for off-resonance.

  • span (float or pair of float, default=None) – Limits of the first and second axis: a half-width about zero or a (low, high) pair, in mm for a position and Hz for off-resonance.

  • samples (int, default=401) – Points per axis; a plane caps at 91 a side.

  • dt (float, default=8e-06) – Integration step in seconds, wherever the window is integrated rather than the pulse alone.

  • whole (bool, default=False) – Integrate everything in the window – every pulse, gradient and the precession between them – rather than the pulse alone. A plane is always integrated this way.

  • title (str, default=None)

  • plot_now (bool, default=True) – Show the figure before returning.

Return type:

matplotlib.figure.Figure

Raises:

ValueError – If source holds no RF event, or the range given holds none.

Notes

A single pulse against one axis is pypulseqpp.sim_rf(), which ignores the gradient: a position axis is its frequency axis over the selection gradient at the pulse centre. Everything else integrates pypulseqpp.sim_bloch() over the window without relaxation.

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