fmri_maskdata
=============

.. currentmodule:: fmri_toolbox

Description
-----------
FMRI_MASKDATA  Applies a binary ROI mask to volume data.
Retains voxels where MASK is non-zero and sets all other voxels to zero.
Both inputs are accepted as either a 91x109x91 volume or a 228453x1
vector; the output matches the format of VOL_DATA.

Usage
-----
.. code-block:: matlab

    masked_data = fmri_maskdata(data, mask)

Inputs
------
- **DATA**: Brain data: volume (91x109x91) or vector (228453x1).
- **MASK**: Binary mask: volume (91x109x91) or vector (228453x1). Typically produced by fmri_regionmask or fmri_spheremask.

Outputs
-------
- **MASKED_DATA**: Vector (228453x1) with out-of-mask voxels set to zero.

Examples
--------
.. code-block:: matlab

    % Mask data to left and right hippocampus (AAL atlas regions 37-38)
    mask = fmri_regionmask(1, [37 38]);
    masked_data = fmri_maskdata(data, mask);
    % Mask data to a 10mm sphere around a peak voxel
    mask = fmri_spheremask(peak_mni, 10);
    masked_data = fmri_maskdata(r_map, mask);

See Also
--------
- fmri_regionmask
- fmri_spheremask
- fmri_vol2vect
- fmri_vect2vol