Writes a self-organizing map struct to a file in SOM_PAK format.
This function is offered for compatibility with SOM_PAK, a SOM
software package in C. It writes map struct to files in SOM_PAK format.
See SOM_READ_COD for description of the SOM_PAK map file format.
Because the SOM_PAK package does not support many of the features and
options of the SOM Toolbox, some of the information is changed, or even
SOM_PAK does not support 3- or higher dimensional map grids. These cannot
be exported using this function.
SOM_PAK always supposes that the map has 'sheet' shape.
SOM_PAK only supports 'bubble' and 'gaussian' neighborhood functions.
Any other neighborhood function is changed to 'gaussian'.
SOM_PAK doesn't support component names. However, the component names are
written on a comment line which begins with '#n '. Any spaces (' ')
in the component names are replaced with underscores ('_').
Information on map name, mask, training history and normalizations is lost.
This function is only offered for compatibility with SOM_PAK. In general,
when saving map structs in files, use 'save filename.mat sMap'. This is
faster and retains all information of the map.
Required input arguments
sMap (struct) the SOM struct to be written
filename (string) the name of the input file