% FLOATREAD - Read matrix from float file ssuming four byte floating point number
% Can use FSEEK to read an arbitrary (contiguous) submatrix.
%
% Usage: >> a = floatread(filename,size,'format',offset)
%
% Inputs:
% filename - name of the file
% size - determine the number of float elements to be read and
% the dimensions of the resulting matrix. If the last element
% of 'size' is Inf, the size of the last dimension is determined
% by the file length. If size is 'square,' FLOATREAD attempts
% to read a square 2-D matrix.
%
% Optional inputs:
% 'format' - the option FORMAT argument specifies the storage format as
% defined by FOPEN. Default format ([]) is 'native'.
% offset - either the number of first floats to skip from the beginning of the
% float file, OR a cell array containing the dimensions of the original
% data matrix and a starting position vector in that data matrix.
%
% Example: % Read a [3 10] submatrix of a four-dimensional float matrix
% >> a = floatread('mydata.fdt',[3 10],'native',{[[3 10 4 5],[1,1,3,4]});
% % Note: The 'size' and 'offset' arguments must be compatible both
% % with each other and with the size and ordering of the float file.
%
% Author: Sigurd Enghoff, CNL / Salk Institute, La Jolla, 7/1998
%
% See also: FLOATWRITE, FOPEN
% Copyright (C) Sigurd Enghoff, CNL / Salk Institute, La Jolla, 7/1998
%
% This file is part of EEGLAB, see http://www.eeglab.org
% for the documentation and details.
%
% Redistribution and use in source and binary forms, with or without
% modification, are permitted provided that the following conditions are met:
%
% 1. Redistributions of source code must retain the above copyright notice,
% this list of conditions and the following disclaimer.
%
% 2. Redistributions in binary form must reproduce the above copyright notice,
% this list of conditions and the following disclaimer in the documentation
% and/or other materials provided with the distribution.
%
% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
% THE POSSIBILITY OF SUCH DAMAGE.
% 04-26-99 modified by Sigurd Enghoff to handle variable-sized and
% multi-dimensional data.
% 07-08-99 modified by Sigurd Enghoff, FORMAT argument added.
% 02-08-00 help updated for toolbox inclusion -sm
% 02-14-00 added segment arg -sm
% 08-14-00 added size 'square' option -sm
% 01-25-02 reformated help & license, added links -ad
function A = floatread(fname,Asize,fform,offset)
if nargin<2
help floatread
return
end
if ~exist('fform') || isempty(fform) || fform(1)==0
fform = 'native';
end
if ~exist('offset')
offset = 0;
end
fid = fopen(fname,'rb',fform);
if fid>0
if exist('offset')
if iscell(offset)
if length(offset) ~= 2
error('offset must be a positive integer or a 2-item cell array');
end
datasize = offset{1};
startpos = offset{2};
if length(datasize) ~= length(startpos)
error('offset must be a positive integer or a 2-item cell array');
end
for k=1:length(datasize)
if startpos(k) < 1 || startpos(k) > datasize(k)
error('offset must be a positive integer or a 2-item cell array');
end
end
if length(Asize)> length(datasize)
error('offset must be a positive integer or a 2-item cell array');
end
for k=1:length(Asize)-1
if startpos(k) ~= 1
error('offset must be a positive integer or a 2-item cell array');
end
end
sizedim = length(Asize);
if Asize(sizedim) + startpos(sizedim) - 1 > datasize(sizedim)
error('offset must be a positive integer or a 2-item cell array');
end
for k=1:length(Asize)-1
if Asize(k) ~= datasize(k)
error('offset must be a positive integer or a 2-item cell array');
end
end
offset = 0;
jumpfac = 1;
for k=1:length(startpos)
offset = offset + jumpfac * (startpos(k)-1);
jumpfac = jumpfac * datasize(k);
end
elseif length(offset) > 1
error('offset must be a positive integer or a 2-item cell array');
end
% perform the fseek() operation
% -----------------------------
stts = fseek(fid,4*offset,'bof');
if stts ~= 0
error('floatread(): fseek() error.');
return
end
end
% determine what 'square' means
% -----------------------------
if ischar('Asize')
if iscell(offset)
if length(datasize) ~= 2 || datasize(1) ~= datasize(2)
error('size ''square'' must refer to a square 2-D matrix');
end
Asize = [datsize(1) datasize(2)];
elseif strcmp(Asize,'square')
fseek(fid,0,'eof'); % go to end of file
bytes = ftell(fid); % get byte position
fseek(fid,0,'bof'); % rewind
bytes = bytes/4; % nfloats
froot = sqrt(bytes);
if round(froot)*round(froot) ~= bytes
error('floatread(): filelength is not square.')
else
Asize = [round(froot) round(froot)];
end
end
end
A = fread(fid,prod(Asize),'float');
else
error('floatread() fopen() error.');
return
end
% fprintf(' %d floats read\n',prod(size(A)));
% interpret last element of Asize if 'Inf'
% ----------------------------------------
if Asize(end) == Inf
Asize = Asize(1:end-1);
A = reshape(A,[Asize length(A)/prod(Asize)]);
else
A = reshape(A,Asize);
end
fclose(fid);
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