transform

Creates a transformed copy of a Pulseq sequence by applying a rotation, translation, or a 4x4 homogeneous transformation matrix. It modifies the sequence's gradient waveforms and calculates updated k-space phase information based on the transformation.

Syntax

function [seq2, gw_pp]= transform(seq, varargin)

Calling Pattern

mr.transform(...)
mr.transform('ParameterName', value, ...)

Parameters

This function accepts both positional parameters and name-value pairs.

Required Parameters

Parameter Name	Value Type	Description	Example	Units
seq	struct	The input Pulseq sequence structure to be transformed.	mySequence

Name-Value Pair Arguments

Parameter Name (string)	Value Type	Default	Description	Example
'rotation'	double	[]	A 3x3 rotation matrix to apply to the sequence. Cannot be used with 'transform'. Valid values: 3x3 numeric matrix	[1 0 0; 0 1 0; 0 0 1]
'translation'	double	[]	A 1x3 translation vector in Pulseq logical coordinates [x, y, z]. Cannot be used with 'transform'. Valid values: 1x3 numeric vector (Units: meters)	[0.01 0 0]
'offset'	double	[]	A translation vector in Pulseq logical coordinates [x, y, z]. Valid values: 1x3 numeric vector (Units: meters)	[0.02, 0, 0]
'transform'	double	[]	A 4x4 homogeneous transformation matrix containing both rotation and translation (in lab coordinates). Cannot be used with 'rotation' or 'translation'. Valid values: 4x4 numeric matrix	[1 0 0 0.01; 0 1 0 0; 0 0 1 0; 0 0 0 1]
'system'	struct	[]	Optional MR system description. If not provided, system properties from the input sequence are inherited.	mr.opts('maxGrad', 40, 'maxSlew', 130)
'sameSeq'	logical	false	If true, the output sequence will be a pointer to the input sequence; otherwise, a copy is created.	true
'blockRange'	double	[1 inf]	Specifies the range of blocks in the sequence to process. The second value can be 'inf' for all blocks. Valid values: 1x2 numeric vector	[10, 20]
'gw_pp'	cell	{}	Optional pre-calculated gradient piecewise polynomial (k-space) data. If provided, the function will reuse this data instead of recalculating it.	{}

Returns

Output	Value Type	Description
seq2	struct	The transformed Pulseq sequence.
'gw_pp'	cell	Gradient piecewise polynomial (k-space) data for the transformed sequence.

Examples

[seq2, gw_pp] = mr.transform(mySequence, 'rotation', rotMatrix, 'offset', [0.01, 0, 0]);
[seq2, gw_pp] = mr.transform(mySequence, 'transform', homogeneousTransformMatrix);

See Also

mr.rotate, mr.rotate3D