rotate¶

Rotates a 3D vector by a given unit quaternion. The function efficiently implements quaternion rotation using explicit formulas to avoid the overhead of general quaternion multiplication.

Syntax¶

function r = rotate(q,v)

Calling Pattern¶

mr.rotate(...)

Parameters¶

Required Parameters¶

Name	Type	Description	Example	Units
`q`	double	A unit quaternion representing the rotation. It should be a 4-element vector or an N x 4 matrix where each row represents a quaternion. The quaternion should be in the form [scalar, vector_x, vector_y, vector_z].	`[1, 0, 0, 0]`
`v`	double	A 3D vector or an N x 3 matrix of 3D vectors to be rotated. Each column represents a component (x, y, z) of the vector.	`[1; 2; 3]`

Returns¶

Output	Type	Description
`r`	double	The rotated vector(s). If 'v' is a 3D vector, 'r' is a 3D vector. If 'v' is an N x 3 matrix, 'r' is an N x 3 matrix where each row represents a rotated vector.

Examples¶

% Rotate gradient and ADC events for spiral imaging
seq.addBlock(mr.rotate('z', phi, gzReph, gx, gy, adc));

% Rotate spoiler gradients by angle phi around z-axis
seq.addBlock(mr.rotate('z', phi, gx_spoil, gy_spoil, gz_spoil));

% Rotate diffusion gradient for 3-axis encoding
Gr = mr.rotate('z', azimuth, mr.rotate('y', polar, gDiff));