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AFNI 3D Voxelwise Calculator (3dcalc)

Library: AFNI | Docker Image: brainlife/afni

Function

Voxelwise mathematical calculator supporting extensive expression syntax for operations on one or more datasets.

Modality: 3D or 4D NIfTI/AFNI volume(s).

Typical Use: Mathematical operations, masking, thresholding, combining datasets.

Key Parameters

-a/-b/-c (input datasets), -expr (mathematical expression), -prefix (output), -datum (output data type)

Key Points

Extremely flexible expression syntax. Supports conditionals, trigonometric, and logical operations. Up to 26 inputs (a-z).

Inputs

Name Type Required Label Flag
a File Yes Input dataset a -a
b File No Input dataset b -b
c File No Input dataset c -c
d File No Input dataset d -d
expr string Yes Mathematical expression to evaluate -expr
prefix string Yes Output dataset prefix -prefix
session string No Output session directory -session
datum enum No Output data type -datum
float boolean No Force float output format -float
short boolean No Force short output format -short
byte boolean No Force byte output format -byte
fscale boolean No Force scaling to maximum integer range -fscale
gscale boolean No Force single scaling factor across all sub-bricks -gscale
nscale boolean No Disable scaling -nscale
dt double No TR for manufactured 3D+time datasets (seconds) -dt
taxis string No Create time axis (N:tstep) -taxis
verbose boolean No Display program progress -verbose
usetemp boolean No Use temporary file for intermediate results -usetemp
isola boolean No Remove isolated non-zero voxels -isola
dicom boolean No Use DICOM/RAI coordinate order -dicom
SPM boolean No Use SPM/LPI coordinate order -SPM

Accepted Input Extensions

  • a: .nii, .nii.gz, +orig.HEAD, +orig.BRIK, +tlrc.HEAD, +tlrc.BRIK
  • b: .nii, .nii.gz, +orig.HEAD, +orig.BRIK, +tlrc.HEAD, +tlrc.BRIK
  • c: .nii, .nii.gz, +orig.HEAD, +orig.BRIK, +tlrc.HEAD, +tlrc.BRIK
  • d: .nii, .nii.gz, +orig.HEAD, +orig.BRIK, +tlrc.HEAD, +tlrc.BRIK

Outputs

Name Type Glob Pattern
result File $(inputs.prefix)+orig.HEAD, $(inputs.prefix)+tlrc.HEAD
log File $(inputs.prefix).log

Output Extensions

  • result: +orig.HEAD, +orig.BRIK, +tlrc.HEAD, +tlrc.BRIK

Enum Options

datum: byte, short, float

Docker Tags

Available versions: latest, 16.3.0

Categories

  • Utilities > AFNI > Image Math

Documentation

Official Documentation