# 3dZeropad¶

```
Usage: 3dZeropad [options] dataset
** Adds planes of zeros to a dataset (i.e., pads it out).
** A negative 'add' count means to cut a dataset down in size.
[Remember 3rd grade arithmetic, please.]
Options:
-I n = adds 'n' planes of zero at the Inferior edge
-S n = adds 'n' planes of zero at the Superior edge
-A n = adds 'n' planes of zero at the Anterior edge
-P n = adds 'n' planes of zero at the Posterior edge
-L n = adds 'n' planes of zero at the Left edge
-R n = adds 'n' planes of zero at the Right edge
-z n = adds 'n' planes of zeros on EACH of the
dataset z-axis (slice-direction) faces
-RL a = These options specify that planes should be added/cut
-AP b = symmetrically to make the resulting volume have
-IS c = 'a', 'b', and 'c' slices in the respective directions.
-pad2evens = add 0 or 1 plane in each of the R/A/S directions,
giving each axis an even number of slices
-mm = pad counts 'n' are in mm instead of slices:
* each 'n' is an integer
* at least 'n' mm of slices will be added/removed:
n = 3 and slice thickness = 2.5 mm ==> 2 slices added
n = -6 and slice thickness = 2.5 mm ==> 3 slices removed
-master mset = match the volume described in dataset 'mset':
* mset must have the same orientation and grid
spacing as dataset to be padded
* the goal of -master is to make the output dataset
from 3dZeropad match the spatial 'extents' of
mset (cf. 3dinfo output) as much as possible,
by adding/subtracting slices as needed.
* you can't use -I,-S,..., or -mm with -master
-prefix ppp = write result into dataset with prefix 'ppp'
[default = 'zeropad']
Nota Bene:
* You can use negative values of n to cut planes off the edges
of a dataset. At least one plane must be added/removed
or the program won't do anything.
* Anat parent and Talairach markers are NOT preserved in the
new dataset.
* If the old dataset has z-slice-dependent time offsets, and
if new (zero filled) z-planes are added, the time offsets
of the new slices will be set to zero.
* You can use program '3dinfo' to find out how many planes
a dataset has in each direction.
* Program works for byte-, short-, float-, and complex-valued
datasets.
* You can use a sub-brick selector on the input dataset.
Author: RWCox - July 2000
++ Compile date = Jul 22 2021 {AFNI_21.2.03:linux_ubuntu_16_64}
```