# 3drotate¶

```
Usage: 3drotate [options] dataset
Rotates and/or translates all bricks from an AFNI dataset.
'dataset' may contain a sub-brick selector list.
GENERIC OPTIONS:
-prefix fname = Sets the output dataset prefix name to be 'fname'
-verbose = Prints out progress reports (to stderr)
OPTIONS TO SPECIFY THE ROTATION/TRANSLATION:
-------------------------------------------
*** METHOD 1 = direct specification:
At most one of these shift options can be used:
-ashift dx dy dz = Shifts the dataset 'dx' mm in the x-direction, etc.,
AFTER rotation.
-bshift dx dy dz = Shifts the dataset 'dx' mm in the x-direction, etc.,
BEFORE rotation.
The shift distances by default are along the (x,y,z) axes of the dataset
storage directions (see the output of '3dinfo dataset'). To specify them
anatomically, you can suffix a distance with one of the symbols
'R', 'L', 'A', 'P', 'I', and 'S', meaning 'Right', 'Left', 'Anterior',
'Posterior', 'Inferior', and 'Superior', respectively.
-rotate th1 th2 th3
Specifies the 3D rotation to be composed of 3 planar rotations:
1) 'th1' degrees about the 1st axis, followed by
2) 'th2' degrees about the (rotated) 2nd axis, followed by
3) 'th3' degrees about the (doubly rotated) 3rd axis.
Which axes are used for these rotations is specified by placing
one of the symbols 'R', 'L', 'A', 'P', 'I', and 'S' at the end
of each angle (e.g., '10.7A'). These symbols denote rotation
about the 'Right-to-Left', 'Left-to-Right', 'Anterior-to-Posterior',
'Posterior-to-Anterior', 'Inferior-to-Superior', and
'Superior-to-Inferior' axes, respectively. A positive rotation is
defined by the right-hand rule.
*** METHOD 2 = copy from output of 3dvolreg:
-rotparent rset
Specifies that the rotation and translation should be taken from the
first 3dvolreg transformation found in the header of dataset 'rset'.
-gridparent gset
Specifies that the output dataset of 3drotate should be shifted to
match the grid of dataset 'gset'. Can only be used with -rotparent.
This dataset should be one this is properly aligned with 'rset' when
overlaid in AFNI.
* If -rotparent is used, then don't use -matvec, -rotate, or -[ab]shift.
* If 'gset' has a different number of slices than the input dataset,
then the output dataset will be zero-padded in the slice direction
to match 'gset'.
* These options are intended to be used to align datasets between sessions:
S1 = SPGR from session 1 E1 = EPI from session 1
S2 = SPGR from session 2 E2 = EPI from session 2
3dvolreg -twopass -twodup -base S1+orig -prefix S2reg S2+orig
3drotate -rotparent S2reg+orig -gridparent E1+orig -prefix E2reg E2+orig
The result will have E2reg rotated from E2 in the same way that S2reg
was from S2, and also shifted/padded (as needed) to overlap with E1.
*** METHOD 3 = give the transformation matrix/vector directly:
-matvec_dicom mfile
-matvec_order mfile
Specifies that the rotation and translation should be read from file
'mfile', which should be in the format
u11 u12 u13 v1
u21 u22 u23 v2
u31 u32 u33 u3
where each 'uij' and 'vi' is a number. The 3x3 matrix [uij] is the
orthogonal matrix of the rotation, and the 3-vector [vi] is the -ashift
vector of the translation.
*** METHOD 4 = copy the transformation from 3dTagalign:
-matvec_dset mset
Specifies that the rotation and translation should be read from
the .HEAD file of dataset 'mset', which was created by program
3dTagalign.
* If -matvec_dicom is used, the matrix and vector are given in Dicom
coordinate order (+x=L, +y=P, +z=S). This is the option to use
if mfile is generated using 3dTagalign -matvec mfile.
* If -matvec_order is used, the matrix and vector are given in the
coordinate order of the dataset axes, whatever they may be.
* You can't mix -matvec_* options with -rotate and -*shift.
*** METHOD 5 = input rotation+shift parameters from an ASCII file:
-dfile dname *OR* -1Dfile dname
With these methods, the movement parameters for each sub-brick
of the input dataset are read from the file 'dname'. This file
should consist of columns of numbers in ASCII format. Six (6)
numbers are read from each line of the input file. If the
'-dfile' option is used, each line of the input should be at
least 7 numbers, and be of the form
ignored roll pitch yaw dS dL dP
If the '-1Dfile' option is used, then each line of the input
should be at least 6 numbers, and be of the form
roll pitch yaw dS dL dP
(These are the forms output by the '-dfile' and
'-1Dfile' options of program 3dvolreg; see that
program's -help output for the hideous details.)
The n-th sub-brick of the input dataset will be transformed
using the parameters from the n-th line of the dname file.
If the dname file doesn't contain as many lines as the
input dataset has sub-bricks, then the last dname line will
be used for all subsequent sub-bricks. Excess columns or
rows will be ignored.
N.B.: Rotation is always about the center of the volume.
If the parameters are derived from a 3dvolreg run
on a dataset with a different center in xyz-space,
the results may not be what you want!
N.B.: You can't use -dfile/-1Dfile with -points (infra).
POINTS OPTIONS (instead of datasets):
------------------------------------
-points
-origin xo yo zo
These options specify that instead of rotating a dataset, you will
be rotating a set of (x,y,z) points. The points are read from stdin.
* If -origin is given, the point (xo,yo,zo) is used as the center for
the rotation.
* If -origin is NOT given, and a dataset is given at the end of the
command line, then the center of the dataset brick is used as
(xo,yo,zo). The dataset will NOT be rotated if -points is given.
* If -origin is NOT given, and NO dataset is given at the end of the
command line, then xo=yo=zo=0 is assumed. You probably don't
want this.
* (x,y,z) points are read from stdin as 3 ASCII-formatted numbers per
line, as in 3dUndump. Any succeeding numbers on input lines will
be copied to the output, which will be written to stdout.
* The input (x,y,z) coordinates are taken in the same order as the
axes of the input dataset. If there is no input dataset, then
negative x = R positive x = L }
negative y = A positive y = P } e.g., the DICOM order
negative z = I positive z = S }
One way to dump some (x,y,z) coordinates from a dataset is:
3dmaskdump -mask something+tlrc -o xyzfilename -noijk
'3dcalc( -a dset+tlrc -expr x -datum float )'
'3dcalc( -a dset+tlrc -expr y -datum float )'
'3dcalc( -a dset+tlrc -expr z -datum float )'
(All of this should be on one command line.)
============================================================================
Example: 3drotate -prefix Elvis -bshift 10S 0 0 -rotate 30R 0 0 Sinatra+orig
This will shift the input 10 mm in the superior direction, followed by a 30
degree rotation about the Right-to-Left axis (i.e., nod the head forward).
============================================================================
Algorithm: The rotation+shift is decomposed into 4 1D shearing operations
(a 3D generalization of Paeth's algorithm). The interpolation
(i.e., resampling) method used for these shears can be controlled
by the following options:
-Fourier = Use a Fourier method (the default: most accurate; slowest).
-NN = Use the nearest neighbor method.
-linear = Use linear (1st order polynomial) interpolation (least accurate).
-cubic = Use the cubic (3rd order) Lagrange polynomial method.
-quintic = Use the quintic (5th order) Lagrange polynomial method.
-heptic = Use the heptic (7th order) Lagrange polynomial method.
-Fourier_nopad = Use the Fourier method WITHOUT padding
* If you don't mind - or even want - the wraparound effect
* Works best if dataset grid size is a power of 2, possibly
times powers of 3 and 5, in all directions being altered.
* The main use would seem to be to un-wraparound poorly
reconstructed images, by using a shift; for example:
3drotate -ashift 30A 0 0 -Fourier_nopad -prefix Anew A+orig
* This option is also available in the Nudge Dataset plugin.
-clipit = Clip results to input brick range [now the default].
-noclip = Don't clip results to input brick range.
-zpad n = Zeropad around the edges by 'n' voxels during rotations
(these edge values will be stripped off in the output)
N.B.: Unlike to3d, in this program '-zpad' adds zeros in
all directions.
N.B.: The environment variable AFNI_ROTA_ZPAD can be used
to set a nonzero default value for this parameter.
INPUT DATASET NAMES
-------------------
This program accepts datasets that are modified on input according to the
following schemes:
'r1+orig[3..5]' {sub-brick selector}
'r1+orig<100..200>' {sub-range selector}
'r1+orig[3..5]<100..200>' {both selectors}
'3dcalc( -a r1+orig -b r2+orig -expr 0.5*(a+b) )' {calculation}
For the gruesome details, see the output of 'afni -help'.
++ Compile date = Sep 1 2021 {AFNI_21.2.06:linux_ubuntu_16_64}
```