som_write_data

Purpose

 Writes data structs/matrices to a file in SOM_PAK format.

Syntax

  som_write_data(sD,'filename')
  som_write_data(D,'filename')
  som_write_data(...,'missing')

Description

 This function is offered for compatibility with SOM_PAK, a SOM software
 package in C. It writes data structs/matrices to a file in SOM_PAK format.

 See SOM_READ_DATA for a decription of the SOM_PAK data file format. Since
 the format does not support information on normalizations, that
 information is lost, as well as the data name. The component names are
 written on a comment line which begins with '#n' and label names on
 comment line which begins with '#l', respectively. Any spaces (' ') in the
 component names and in the label names are replaced with
 underscores ('_').

 This function is only offered for compatibility with SOM_PAK. In
 general, when saving data in files, use 'save filename.mat sData'. This is
 faster and retains all information of the data struct.

 The string to use for missing values (NaNs) in the written file can
 be given with the last argument. Notice that if you use SOM_PAK to
 read the files, you need to set the SOM_PAK environment variable
 LVQSOM_MASK_STR accordingly, e.g. to 'NaN' if you use the default
 replacement. For more information, see the SOM_PAK instructions.

Required input arguments

  data        (struct or matrix) data to be written
  filename    (string) output filename

Optional input arguments

  missing     (string) string used to denote missing components (NaNs); 
               default is 'NaN'

Examples

 The basic usage is:
  som_write_data(sData,'system.data')

 To write a data matrix to a file in plain SOM_PAK format, give a
 data matrix as the first argument: 
  som_write_data(D,'system.data')

 By default, all NaNs in the data matrix are written as 'NaN':s. The
 third argument can be used to change this:
  som_write_data(sData,'system.data','+')
  som_write_data(sData,'system.data','missing')

See also