mrsprint.simulator package

Submodules

mrsprint.simulator.old_plot module

mrsprint.simulator.plot module

mrsprint.simulator.simulator module

Module contents

Package for simulator related classes and objects.

Authors:
Since:
2018/06/07

Todo

Maybe remove old_plot module.

mrsprint.simulator.calculate_t2_star(t2, freq_shift)[source]

Returns the value for t2*, considering the range of frequencies.

Parameters:
  • t2 (float [s]) – T2 value in seconds.
  • freq_shift (float [Hz]) – Frequency shift from resonance - symetric between zero (in resonance).
Returns:

T2 star value.
Return type:

float [s]

Todo

Confirm if it is the right way to calculate or if it has a weight function for t2star Pass freq_shift as a number?

mrsprint.simulator.create_positions(size=(1, 1, 1), step=(1.0, 1.0, 1.0), offset=(0.0, 0.0, 0.0), dtype=<class 'numpy.float32'>)[source]

Creates array of positions.

Parameters:
  • size (tuple(int)) – Size in x, y and z. The minimum number is one for each axis.
  • step (tuple(float)) – Step for each axis.
  • offset (tuple(float)) – Offset for each axis. If zero, the final vector begins in zero and ends in size plus offset.
Returns:

Position array in this format [[gr_x_plotx gr_y_plotx gr_z_plotx …]

[gr_x_ploty gr_y_ploty gr_z_ploty …][gr_x_plotz gr_y_plotz gr_z_plotz …]], where p is the number of position (from offset to size plus offset).
Return type:

np.array

Todo

Set physical unit for each args.

mrsprint.simulator.frequency_shift(freq_shift, freq_step=1.0, offset=0.0, symetric=True, dtype=<class 'numpy.float32'>)[source]

Generates an array of frequency shift, from -frequency_shift to +frequency_shift, between offset.

Parameters:
  • freq_shift (float [Hz]) – Maximum frequency to shift.
  • freq_step (float [Hz]) – Spacing between values.
  • offset (float [Hz]) – Offset frequency.
  • symetric (bool) – If true, generates the array between offset (-maximum shift, maximum shift), otherwise from offset to maximum frequency. Default is True.
  • dtype (np.dtype) – Data type for the array. Default is np.float32.
Returns:

Array of frequency shift value.
Return type:

np.array [Hz]

Todo

Use the key symetric for something.

mrsprint.simulator.reduce_magnetization_in_frequency(mx, my, mz, freq_shift, fsa_size)[source]

Reduces the magnetization vector by summing frequency components.

Parameters:
  • mx (np.array) – Array of magnetization x without reduction in frequency.
  • my (np.array) – Array of magnetization y without reduction in frequency.
  • mz (np.array) – Array of magnetization z without reduction in frequency.
  • freq_shift (np.array) – Array of frequency shift.
  • fsa_size (int) – Size of array of frequency shift.
Returns:

(mx, my, mz) arrays of magnetization reduced
Return type:

tuple

Todo

Shape size different of 2. Better solution for freq_shift array. Set physical unit for each args.

mrsprint.simulator.reduce_magnetization_in_position(mx, my, mz, position, freq_shift)[source]

Reduces the magnetization vector by summing position components.

Parameters:
  • mx (np.array) – Array of x magnetization without reduction in frequency.
  • my (np.array) – Array of y magnetization without reduction in frequency.
  • mz (np.array) – Array of z magnetization without reduction in frequency.
  • position (np.array) – Array of positions.
  • freq_shift (np.array) – Array of frequency shift.
Returns:

(mx, my, mz) arrays of magnetization reduced.
Return type:

tuple

Todo

Test shape size different of 2. Set physical unit for each args.

mrsprint.simulator.transform_cart_to_pol(x, y)[source]

Returns a transformed catesian vector into polar coordinates.

Parameters:
  • x (np.array) – X coordinate.
  • y (np.array) – Y coordinate.
Returns:

(rho, phi) vectors formed by radial and angular coordinates.
Return type:

tuple
mrsprint.simulator.transform_pol_to_cart(rho, phi)[source]

Returns a transformed polar vector into cartesian coordinates.

Parameters:
  • rho (np.array) – Radial coordinate.
  • phi (np.array) – Angular coordinate.
Returns:

(x, y) vectors formed by x and y coordinates
Return type:

tuple