Plotting of Bloch Profiles

i.e. The frequency domain profiles generated by applying the Bloch equations to the time domain waveform.

We currently list 4 possible waveform types and 4 UsageTypes (more later), implying a total of 16 combinations.

These can all be generated using this function:

fy, fx = result.get_profile(use_type, get_extended, get_absolute)

fy is a complex waveform; although one of the two axes may have a value of zero.
fx is a real array (with the same number of points as in fy).
‘result' *is of type mrs_result.

The input values are:

use_type: One of the choices from constants.UsageType. e.g. {Excite, Inversion, Saturation, Spin-Echo}
get_extended: True or False. True if you want the extended waveform.
get_absolute: True or False. True if want the absolute value.

By default we usually want the following plots:

Excite, Spin-Echo: Both the real and imaginary components.
Inversion, and Saturation: The real component (Note, however, that the imaginary component has been set to zero for these view types).

However, we could just show both the magnitude (complex plot) AND the absolute magnitude of every pulse.