Events#

class mrsd.Event(duration, amplitude, begin=None, end=None, center=None, offset=None, **kwargs)#

Abstract sequence event

Parameters:

  • duration – total duration.

  • amplitude – normalized amplitude between -1 and +1.

  • begin,end,center – time of the begin, end, or center of the event. Only one must be specified.

  • offset – horizontal and vertical offset to position the event.

  • kwargs – passed to matplotlib.patches.Patch

move(offset)#

Move on the time axis, return the object

ADC#

class mrsd.ADC(duration, **kwargs)#

ADC/readout event, represented by a rectangle of amplitude 1.

Echo#

class mrsd.Echo(duration, amplitude=1, **kwargs)#

Echo event, represented by an oscillating exponential.

Gradient#

class mrsd.Gradient(flat_top, amplitude, ramp=0, **kwargs)#

Gradient event, represented by a trapezoid.

Parameters:

  • flat_top – duration of the gradient flat-top

  • amplitude – amplitude of the gradient flat-top

  • ramp,ramp_up,ramp_down – ramp durations of the gradient. Use ramp for symmetric gradients, and both ramp_up and ramp_down for asymmetric gradients

adapt(flat_top, area_factor, ramp=0, ramp_up=None, ramp_down=None, **kwargs)#

Return a gradient with an area equal to a factor of the current gradient.

Multi-Gradient#

class mrsd.MultiGradient(flat_top, amplitude, ramp=0, steps=5, **kwargs)#

Multiple gradient events (e.g. phase encoding), represented by nested trapezoids.

Parameters:

  • flat_top – duration of the gradient flat-top

  • amplitude – maximum amplitude of the gradient flat-top

  • ramp,ramp_up,ramp_down – ramp durations of the gradient. Use ramp for symmetric gradients, and both ramp_up and ramp_down for asymmetric gradients

  • steps – number of steps drawn between the maximum and minimum amplitude

RF Pulse#

class mrsd.RFPulse(duration, amplitude, envelope=<function sinc_envelope>, **kwargs)#

RF pulse event, represented by a user-defined envelope

Parameters:

  • duration – duration of the pulse

  • amplitude – maximum amplitude

  • envelope – sinc_envelope (default), box_envelope, or gaussian_envelope

  • lobes – number of lobes on each side of a sinc envelope (defaults to 3)

  • apodization – apodization of a sinc envelope (None (default), “hann”, or “hamming”)

  • sd – standard deviation of a Gaussian envelope (defaults to 0.3)

  • points – number of points used to draw the envelope (defaults to 101)