Mercurial > hg > octave-nkf
changeset 15546:3bf1e0da76b0
importdata: new function
author | Erik Kjellson <erikiiofph7@users.sourceforge.net> |
---|---|
date | Fri, 19 Oct 2012 13:56:22 -0400 |
parents | 0272bb60408a |
children | 9a455cf96dbe |
files | scripts/io/importdata.m |
diffstat | 1 files changed, 265 insertions(+), 0 deletions(-) [+] |
line wrap: on
line diff
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