Converts a sparse coordinate list to its non-sparse volumetric representation.
coordlist_to_vol(coords, fill = FALSE)The volumetric data
The sparse coordinate list. Should be a "data.frame" or
matrix with voxels along the rows and three or four columns. The first three
columns should be integers indicating the spatial coordinates of the voxel.
If the fourth column is present, it will be the value used for that voxel.
If it is absent, the value will be TRUE or 1 if fill
is not one of those values, and FALSE or 0 if fill is.
The data type will be the same as that of fill. The fourth column
must be logical or numeric.
Logical or numeric fill value for the volume. Default:
FALSE.