fmri_sub2ind
============

.. currentmodule:: fmri_toolbox

Description
-----------
FMRI_SUB2IND  Converts voxel subscripts to linear brain indices.
Converts one or more voxel subscripts [x y z] in the 91x109x91 volume
space to linear indices in the 228453-element vectorized brain space.

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

    ind = fmri_sub2ind(sub)

Inputs
------
- **SUB**: Subscript matrix (N x 3): [x1 y1 z1; x2 y2 z2; ...].
- **1**: based MATLAB indices in the 91x109x91 volume.

Outputs
-------
- **IND**: Linear brain indices (N x 1). Values in [1, 228453]. Returns NaN for subscripts outside the brain mask.

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

    ind  = fmri_sub2ind([46 64 37]);        % centre of the brain
    inds = fmri_sub2ind([46 64 37; 30 50 45]);

See Also
--------
- fmri_ind2sub
- fmri_mni2sub
- fmri_spheremask