# HG changeset patch
# User Erik Kjellson <erikiiofph7@users.sourceforge.net>
# Date 1350669382 14400
# Node ID 3bf1e0da76b01561eab11a98a9da1b10e87b3237
# Parent  0272bb60408a276b12f459f5087aa4ed39f53121
importdata: new function

diff --git a/scripts/io/importdata.m b/scripts/io/importdata.m
new file mode 100644
--- /dev/null
+++ b/scripts/io/importdata.m
@@ -0,0 +1,265 @@
+## Copyright (C) 2012 Erik Kjellson <erikiiofph7@users.sourceforge.net>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn  {Function File} {@var{A} =} importdata (@var{fileName})
+## @deftypefnx {Function File} {@var{A} =} importdata (@var{fileName}, @var{delimiter})
+## @deftypefnx {Function File} {@var{A} =} importdata (@var{fileName}, @var{delimiter},  @var{headerRows})
+## @deftypefnx {Function File} {[@var{A}, @var{delimiter}] =} importdata (...)
+## @deftypefnx {Function File} {[@var{A}, @var{delimiter}, @var{headerRows}] =} importdata (...)
+## Importing data from file.
+##
+## Importing the contents of file @var{fileName} into workspace.
+##
+## Input parameters:
+## @table @input
+## @item @var{fileName}
+## The file name for the file to import.
+## 
+## @item @var{delimiter}
+## The character separating columns of data. Use @code{\t} for tab. (Only valid for ascii files)
+##
+## @item @var{headerRows}
+## Number of header rows before the data begins. (Only valid for ascii files)
+## @end table
+##
+## Different file types are supported:
+## @itemize
+## @item Ascii table
+##
+## Importing ascii table using the specified number of header rows and the specified delimiter.
+##
+## @item Image file
+##
+## @item Matlab file
+##
+## @item Wav file
+##
+## @end table
+##
+## @seealso{textscan, dlmread, csvread, load}
+## @end deftypefn
+
+## Author: Erik Kjellson <erikiiofph7@users.sourceforge.net>
+## 2012-10-16 First version
+
+
+function [output, delimiter, headerRows] = importdata(varargin)
+
+  # Default values
+  fileName   = '';
+  delimiter  = '';
+  headerRows = -1;
+
+  ##########
+
+  # Check input arguments
+
+  if (nargin < 1)
+    print_usage ();
+  endif
+
+  fileName = varargin{1};
+  # Check that the file name really is a string
+  if not(ischar(fileName))
+    error('importdata: File name needs to be a string.')
+  endif
+  if strcmpi(fileName, '-pastespecial')
+    error('importdata: Option ''-pastespecial'' not implemented.')
+  endif
+
+  if (nargin > 1)
+    delimiter = varargin{2};
+    # Check that the delimiter really is a string
+    if not(ischar(delimiter))
+      error('importdata: Delimiter needs to be a character.')
+    endif
+    if ((length(delimiter) > 1) && not(strcmpi(delimiter, '\t')))
+      error('importdata: Delimiter cannot be longer than 1 character.')
+    endif
+    if strcmpi(delimiter, '\')
+      delimiter = '\\';
+    endif
+  endif
+
+  if (nargin > 2)
+    headerRows = varargin{3};
+    if ((~isnumeric(headerRows)) || (headerRows < 0))
+      error('importdata: Number of header rows needs to be an integer number >= 0.')
+    endif
+  endif
+
+  if (nargin > 3)
+    error('importdata: Too many input arguments.')
+  endif
+
+  ##########
+
+  # Check file format
+  # Get the extension from the file name.
+  [d n fileExt v] = fileparts(fileName);
+  # Make sure file extension is in lower case.
+  fileExt = lower(fileExt);
+
+  switch fileExt
+    case {'.au','.snd'}
+      error(['importdata: Not implemented for file format ''' fileExt '''.'])
+    case '.avi'
+      error(['importdata: Not implemented for file format ''' fileExt '''.'])
+    case {'.bmp', '.cur', '.gif', '.hdf', '.ico', '.jpe', '.jpeg', '.jpg', '.pbm', '.pcx', '.pgm', '.png', '.pnm', '.ppm', '.ras', '.tif', '.tiff', '.xwd'}
+      delimiter  = NaN;
+      headerRows = 0;
+      [output.cdata, output.colormap, output.alpha] = imread(fileName);
+    case '.mat'
+      delimiter  = NaN;
+      headerRows = 0;
+      output = load(fileName);
+    case '.wk1'
+      error(['importdata: Not implemented for file format ''' fileExt '''.'])
+    case {'.xls', '.xlsx'}
+  #FIXME: implement Excel import.
+      error(['importdata: Not implemented for file format ''' fileExt '''.'])
+    case {'.wav', '.wave'}
+      delimiter  = NaN;
+      headerRows = 0;
+      [output.data, output.fs] = wavread(fileName);
+    otherwise
+      # Assume the file is in ascii format.
+      [output, delimiter, headerRows] = importdata_ascii(fileName, delimiter, headerRows);
+  endswitch
+
+  # If there are any empty fields in the output structure, then remove them
+  if (isstruct(output) && (length(output) == 1))
+    fields = fieldnames(output);
+    for i=1:length(fields)
+      if isempty(getfield(output, fields{i}))
+        output = rmfield(output, fields{i});
+      endif
+    endfor
+
+    # If only one field is left, replace the structure with the field, i.e. output = output.onlyFieldLeft
+    # Update the list of fields
+    fields = fieldnames(output);
+    if (length(fields) == 1)
+      output = getfield(output, fields{1});
+    endif
+  endif
+endfunction
+
+
+########################################
+
+function [output, delimiter, headerRows] = importdata_ascii(fileName, delimiter, headerRows)
+
+  # Define the fields in the output structure so that the order will be correct.
+  output.data       = [];
+  output.textdata   = [];
+  output.rowheaders = [];
+  output.colheaders = [];
+
+  # Read file into string and count the number of header rows
+
+  fileContent = fileread(fileName);
+  # The characters need to be in a row vector instead of a column vector to be recognized as a proper string.
+  if (size(fileContent,2) == 1)
+    fileContent = fileContent';
+  endif
+
+  # Split the file into rows (using \r\n or \n as delimiters between rows).
+  fileContentRows = regexp(fileContent, '\r?\n', 'split');
+
+  #FIXME: guess delimiter, if it isn't defined
+  if (isempty(delimiter))
+    error('importdata: Guessing delimiter is not implemented yet, you have to specify it.')
+  endif
+
+  #FIXME: A more intelligent way to count number of header rows. This is needed e.g. when delimiter=' ' and the header contains spaces...
+
+  # If number of header rows is undefined, then count the number of header rows by step through row by row and look for the delimiter.
+  # Assume that the header can't contain any delimiter.
+  if (headerRows < 0)
+    headerRows = 0;
+    for i=1:length(fileContentRows)
+      if (isempty(regexp(fileContentRows{i}, delimiter, 'once')))
+        headerRows++;
+      else
+        # Data part has begun and therefore no more header rows can be found
+        break;
+      endif
+    endfor
+  endif
+
+  # Put the header rows in output.textdata.
+  if (headerRows > 0)
+    output.textdata   = fileContentRows(1:headerRows)';
+  endif
+
+  # If space is the delimiter, then remove spaces in the beginning of each data row.
+  if strcmpi(delimiter, ' ')
+    for i=(headerRows+1):length(fileContentRows)
+      # strtrim does not only remove the leading spaces but also the tailing spaces, but that doesn't really matter.
+      fileContentRows{i} = strtrim(fileContentRows{i});
+    endfor
+  endif
+
+  # Remove empty data rows. Go through them backwards so that you wont get out of bounds.
+  for i=length(fileContentRows):-1:(headerRows+1)
+    if (length(fileContentRows{i}) < 1)
+      fileContentRows = [fileContentRows(1:i-1), fileContentRows(i+1:length(fileContentRows))];
+    endif
+  endfor
+
+  # Count the number of data columns.
+  # If there are different number of columns, use the greatest value.
+  dataColumns = 0;
+  delimiterPattern = delimiter;
+  # If space is the delimiter, then multiple spaces should count as ONE delimiter. Also ignore leading spaces.
+  if (strcmpi(delimiter, ' '))
+    delimiterPattern = ' +';
+  endif
+  for i=(headerRows+1):length(fileContentRows)
+    dataColumns = max(dataColumns, length(regexp(fileContentRows{i}, delimiterPattern, 'split')));
+  endfor
+
+
+  # Go through the data and put it in either output.data or output.textdata depending on if it is numeric or not.
+  output.data = NaN(length(fileContentRows)-headerRows, dataColumns);
+  for i=(headerRows+1):length(fileContentRows)
+    # Only use the row if it contains anything other than white-space characters.
+    if (length(regexp(fileContentRows{i}, '\S','match')) > 0)
+      rowData = regexp(fileContentRows{i}, delimiterPattern, 'split');
+      for j=1:length(rowData)
+        # Try to convert the column to a number, if it works put it in output.data, otherwise in output.textdata
+        if (length(str2num(rowData{j})) > 0)
+          output.data((i-headerRows),j) = str2num(rowData{j});
+        else
+          output.textdata{i,j} = rowData{j};
+        endif
+      endfor
+    endif
+  endfor
+
+  # Check wether rowheaders or colheaders should be used
+  if ((headerRows == dataColumns) && (size(output.textdata,2) == 1))
+    output.rowheaders = output.textdata;
+  elseif (size(output.textdata,2) == dataColumns)
+    output.colheaders = output.textdata(end,:);
+  endif
+
+  # When delimiter = '\t' convert it to a tab, as is done in the Matlab version
+  if (strcmpi(delimiter, '\t'))
+    delimiter = sprintf('\t');
+  endif
+endfunction