---
name: "cmtk-ttest"
section: "1"
platform: "linux"
package: "cmtk"
version: "3.3.1p2+dfsg-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/cmtk-ttest"
---

# cmtk-ttest(1)

T-tests

## NAME

ttest - T-tests

## SYNOPSIS

ttest \[options\] imageX0 \[imageX1 ...\] -- imageY0 \[imageY1\] ... ttest \[options\] --symmetric imageX0 \[imageX1 ...\]

## DESCRIPTION

Pixelwise tests of statistical significance. Also compute correlations and z-scores

## OPTIONS

### Global Toolkit Options (these are shared by all CMTK tools)

- **--help**

  Write list of basic command line options to standard output.

- **--help-all**

  Write complete list of basic and advanced command line options to standard output.

- **--wiki**

  Write list of command line options to standard output in MediaWiki markup.

- **--man**

  Write man page source in 'nroff' markup to standard output.

- **--version**

  Write toolkit version to standard output.

- **--echo**

  Write the current command line to standard output.

- **--verbose-level** *\<integer\>*

  Set verbosity level.

- **--verbose**, **-v**

  Increment verbosity level by 1 (deprecated; supported for backward compatibility).

- **--threads** *\<integer\>*

  Set maximum number of parallel threads (for POSIX threads and OpenMP).

### Main Options

- **--log**, **-l**

  Use log data for testing

- **--abs**, **-a**

  Use absolute data for testing

- **--abs-out**, **-A**

  Generate absolute (unsigned) data

- **--invert**, **-i**

  Invert data, i.e., subtract from 1.0

- **--short**, **-s**

  Convert probabilities to short (and scale by 1000)

- **--paired**, **-p**

  Compute paired t-test \[default: groupwise\]

- **--cross-correlation**, **-c**

  Compute paired cross-correlation

- **--zscores**, **-Z**

  Compute z-scores of test (y) distribution averages

- **--text**, **-t**

  Text file input and output rather than image files.

- **--mask** *\<string\>*, **-m** *\<string\>*

  Mask file name **\[Default: NONE\]**

- **--outfile** *\<string\>*, **-o** *\<string\>*

  Output file name **\[Default: ttest.nii \]**

- **--tstats-file** *\<string\>*

  T-statistics output file name (for correlation: p-value output file) **\[Default: NONE\]**

## AUTHORS

Torsten Rohlfing, with contributions from Michael P. Hasak, Greg Jefferis, Calvin R. Maurer, Daniel B. Russakoff, and Yaroslav Halchenko

## LICENSE

http://www.fsf.org/licensing/licenses/gpl.html

## BUGS

Report bugs at http://nitrc.org/projects/cmtk/

## ACKNOWLEDGMENTS

CMTK is developed with support from the NIAAA under Grant AA021697, National Consortium on Alcohol and Neurodevelopment in Adolescence (N-CANDA): Data Integration Component. From April 2009 through September 2011, CMTK development and maintenance was supported by the NIBIB under Grant EB008381.