function [err, V, Info, ErrMessage] = BrikLoad (BrikName, param1, param2)
%
%  OLD USAGE for backward compatibility, see New Usage
%
%   [err, V, Info, ErrMessage] = BrikLoad (BrikName, [form], [MachineFormat])
%
%Purpose:
%   loads an AFNI brik into V
%   
%   
%Input Parameters:
%   BrikName, name of the brik
%   form, 'vector' or 'matrix' this is optional, the default is matrix
%        see .Format help under NEW USAGE
%   MachineFormat is a string such as 'native' or 'ieee-le' (LSB_FIRST) or 'ieee-be' (MSB_FIRST)
%        see .MachineFormat help under NEW USAGE
%
%
%  NEW USAGE
%
%   [err, V, Info, ErrMessage] = BrikLoad (BrikName, [Opt])
%
%Purpose:
%   loads an AFNI brik or a 1D file into V
%   
%   
%Input Parameters:
%   BrikName, name of the brik
%   Opt is an options format with the following optional fields
%   .Format, 'vector' or 'matrix', the default is matrix
%        This determines how the brick data is returned in V.
%        If you choose 'vector' then a N x M x K volume is stored in a 
%        (N * M * K) column vector. If the brick has multiple volumes (4-D)
%        then an N x M x K x J brick is stored in an (N * M * K) x J  matrix.
%        If you use 'vector' option you can change V to matrix format by using
%        M = reshape(V, Info.DATASET_DIMENSIONS(1), Info.DATASET_DIMENSIONS(2),...
%            Info.DATASET_DIMENSIONS(3), Info.DATASET_RANK(2));
%        
%        Note that indexing in matlab is different than in AFNI. Matlab starts indexing at 
%        1 while AFNI starts with 0. So voxel (i,j,k) in AFNI corresponds to voxel (i+1,j+1,k+1) 
%        in matlab. (see example below).
%
%   .MachineFormat is a string such as 'native' or 'ieee-le' (LSB_FIRST) or 'ieee-be' (MSB_FIRST)
%       default is whatever is specified in the .HEAD file.
%       If nothing is specified in the .HEAD file, MSB_FIRST or 'ieee-be' is assumed
%       since most files created with the old versions of AFNI were on the SGIs .
%        You must specify the parameter Opt.Format, to specify Opt.MachineFormat and override the defaults
%       see help fopen for more info 
%
%   .Scale 0/1 if 1, then the scaling factor is applied to the values read from the brik
%        default is 1
%
%   .Slices: vector of slices, 1 based. Default is all slices. 
%            Read the set of slices specified in .Slices (added for FMRISTAT)
%
%   .Frames: vector of frames, 1 based. Default is all frames. 
%            Read the sub-bricks specified in .Frames (added for FMRISTAT)
%   .method: method option for Read_1D if you are using 1D files.
%           see Read_1D -help for more info
% WARNING: If you use .Scale = 0 , you may get bad time series if you have multiple subbriks ! 
%     Each subbrik can have a different scaling factor
%   
%Output Parameters:
%   err : 0 No Problem
%       : 1 Mucho Problems
%   V : the brik data in vector or matrix (X,Y,Z,t) form
%   Info : is a structure containing some Brik infor (from .HEAD file)
%     ErrMessage: An error or warning message
%      
%Key Terms:
%   
%More Info :
%   How to read a brick and display a time series:
%   %read the 3D+time brick
%   [err, V, Info, ErrMessage] = BrikLoad ('ARzs_CW_r5+orig'); 
%   %plot the time course of voxel (29, 33, 3)
%   plot (squeeze(V(30 , 34, 4, :))); %squeeze is used to turn the 1x1x1x160 matrix into a 160x1 vector for the plot function
%   
%   
%
%   see also BrikInfo, Info_1D, WriteBrik
%
%     The core for this function (fread and reshape) is based on 
%     Timothy M. Ellmore's (Laboratory of Brain and Cognition, NIMH)
%     function ReadBRIK 
%     
%     .Slices and .Frames options were added by Dr. Keith Worsley for FMRISTAT
%     http://www.math.mcgill.ca/keith
%     http://www.math.mcgill.ca/keith/fmristat/
%
%     Author : Ziad Saad  Mon Oct 18 14:47:32 CDT 1999 
%     Biomedical Engineering, Marquette University
%     Biophysics Research institute, Medical College of Wisconsin
%
%     Contact: ziad@nih.gov


%Define the function name for easy referencing
FuncName = 'BrikLoad';

%Debug Flag
DBG = 1;

%initailize return variables
err = 1;
V = [];
Info = [];
ErrMessage = '';

switch nargin,
   case 1,
      DoVect = 0;
      Opt.MachineFormat = '';
      Opt.Format = 'matrix';
      Opt.Scale = 1;
      Opt.Slices = [];
      Opt.Frames = [];
      Opt.FileFormat = '';
   case 2,
      if (~isstruct(param1)),
         Opt.Format = param1;
         Opt.MachineFormat = '';
         Opt.Scale = 1;
         Opt.Slices = [];
         Opt.Frames = [];
         Opt.FileFormat = '';
      else
         Opt = param1;
         if (~isfield(Opt,'FileFormat')),   Opt.FileFormat = ''; end
      end
   case 3,
         Opt.Format = param1;
         Opt.MachineFormat = param2;
         Opt.Scale = 1;
         Opt.Slices = [];
         Opt.Frames = []; 
         Opt.FileFormat = '';         
   otherwise,
   err= ErrEval(FuncName,'Err_Bad option');
   return;
end

% Are we dealing with a .1D file ?
is1D = 0;
if (isempty(Opt.FileFormat)), % try to guess 
   [St, xtr] = Remove1DExtension(BrikName);
   if (~isempty(xtr)),
      is1D = 1;
   end
elseif (strcmp(Opt.FileFormat, '1D') || strcmp(Opt.FileFormat, '1d')),
   is1D = 1;
end

if (is1D), % 1D land
   V = []; Info = []; ErrMessage = '';
   Opt.verb = 1;
   if (~isfield(Opt, 'method') || isempty(Opt.method)), Opt.method = 0; end
   [err, V, Info] = Read_1D(BrikName, Opt);
   if (err), 
      ErrMessage = sprintf ('%s: Failed to read %s file', FuncName, BrikName);
      err = ErrEval(FuncName,'Err_1D file could not be read');
      return;
   end
   return;
end

%assume you have a brik format and proceed as usual 
%make sure Opt fields are set OK. That's done for the new usage format
%   if (~isfield(Opt,'') | isempty(Opt.)),   Opt. = ; end
   if (~isfield(Opt,'Format') | isempty(Opt.Format)),   Opt.Format = 'matrix'; end
   if (~isfield(Opt,'MachineFormat') | isempty(Opt.MachineFormat)),   Opt.MachineFormat = ''; end
   if (~isfield(Opt,'Scale') | isempty(Opt.Scale)),   Opt.Scale = 1; end %you can change the default for the new usage here
   if (~isfield(Opt,'Slices') | isempty(Opt.Slices)),   Opt.Slices = []; end 
   if (~isfield(Opt,'Frames') | isempty(Opt.Frames)),   Opt.Frames = []; end 
   if (~isfield(Opt,'FileFormat') | isempty(Opt.FileFormat)),   Opt.FileFormat = ''; end
   

%set the format   
   if (eq_str(Opt.Format,'vector')),
      DoVect = 1;
   elseif(eq_str(Opt.Format,'matrix')),
      DoVect = 0;
   end

%Fix the name of the brik
   %make sure there are no .BRIK or .HEAD   
   vtmp = findstr(BrikName,'.BRIK');
   if (~isempty(vtmp)), %remove .BRIK
      BrikName = BrikName(1:vtmp(1)-1);
   end
   
   vtmp = findstr(BrikName,'.HEAD');
   if (~isempty(vtmp)), %remove .HEAD
      BrikName = BrikName(1:vtmp(1)-1);
   end


   %Now make sure .HEAD and .BRIK are present
   sHead = sprintf('%s.HEAD', BrikName);
   sBRIK = sprintf('%s.BRIK', BrikName);
   if (~filexist(sHead)), 
      ErrMessage = sprintf ('%s: %s not found', FuncName, sHead);
      err = ErrEval(FuncName,'Err_HEAD file not found');
      return;
   end
   if (~filexist(sBRIK)), 
      ErrMessage = sprintf ('%s: %s not found', FuncName, sBRIK);
      err = ErrEval(FuncName,'Err_BRIK file not found');
      return;
   end

   
%get Brik info and setup for slice and frame selectors (for FMRISTAT)
   [err, Info] = BrikInfo(BrikName);

   allslices=1:Info.DATASET_DIMENSIONS(3);
   if  (~isfield(Opt,'Slices') | isempty(Opt.Slices)),   
      Opt.Slices = allslices; 
   end
   isallslices=all(ismember(allslices,Opt.Slices));
   allframes=1:Info.DATASET_RANK(2);
   if  (~isfield(Opt,'Frames') | isempty(Opt.Frames)),   
      Opt.Frames = allframes; 
   end
   isallframes=all(ismember(allframes,Opt.Frames));

   if (~strcmp(Info.ByteOrder,'unspecified')),
      %found byte order specs, make sure it does not conflict with the user option
      if (~isempty(Opt.MachineFormat)),
         %user specified a format
         if (~strcmp(Info.ByteOrder,Opt.MachineFormat)),
            %clash, warn
            ErrEval(FuncName,'Wrn_Machine format specified conflicts with .HEAD info. Proceeding with fread ...');
         end
      else
         Opt.MachineFormat = Info.ByteOrder;
      end
   else
      %did not find ByteOrder in .HEAD, use user option or pick default
      if (isempty(Opt.MachineFormat)),
         Opt.MachineFormat = 'ieee-be';
         ErrEval(FuncName,'Wrn_No Machine Format was specified by user or found in .HEAD file. Using ieee-be (MSB_FIRST)');
      end
   end

%figure out storage type
   itype = unique(Info.BRICK_TYPES);
   if (length(itype) > 1),
      err =  1; ErrMessage = sprintf('Error %s: Not set up to read sub-bricks of multiple sub-types', FuncName); errordlg(ErrMessage);
      return;
   end
   switch itype,
      case 0
         typestr = 'ubit8';
      case 1
         typestr = 'short';
      case 2
         typestr = 'int';
      case 3
         typestr = 'float';
      otherwise
         err = ErrEval(FuncName,'Err_Cannot read this data type');
         return;
   end
   
%read .BRIK file
   BrikName = sprintf('%s.BRIK', BrikName);
   
   fidBRIK = fopen(BrikName, 'rb', Opt.MachineFormat);
   if (fidBRIK < 0),
      err = ErrEval(FuncName,'Err_Could not open .BRIK file');
      return;
   end
   
   numpix=Info.DATASET_DIMENSIONS(1)*Info.DATASET_DIMENSIONS(2);
   numslices=length(Opt.Slices);
   numframes=length(Opt.Frames);

   if isallslices & isallframes
      V = fread(fidBRIK, (Info.DATASET_DIMENSIONS(1) .* Info.DATASET_DIMENSIONS(2) .* Info.DATASET_DIMENSIONS(3) .* Info.DATASET_RANK(2)) , typestr);
   else
      V=zeros(1,numpix*numslices*numframes);
      for k=1:numframes
         frame=Opt.Frames(k);
         if isallslices
            fseek(fidBRIK, numpix*Info.DATASET_DIMENSIONS(3)*(frame-1)*Info.TypeBytes, 'bof');
            istrt=1+numpix*numslices*(k-1);
            istp=istrt-1+numpix*numslices;
            V(istrt:istp)=fread(fidBRIK,numpix*numslices,typestr);
         else
            for j=1:numslices
               slice=Opt.Slices(j);
               fseek(fidBRIK, numpix*(slice-1+Info.DATASET_DIMENSIONS(3)*(frame-1))*Info.TypeBytes, 'bof');
               istrt=1+numpix*(j-1+numslices*(k-1));
               istp=istrt-1+numpix;
               V(istrt:istp)=fread(fidBRIK,numpix,typestr);
            end
         end
      end
   end
   fclose (fidBRIK);

%scale if required
   if (Opt.Scale),
      facs=Info.BRICK_FLOAT_FACS(Opt.Frames);
      iscl = find (facs); %find non zero scales
      NperBrik = Info.DATASET_DIMENSIONS(1) .* Info.DATASET_DIMENSIONS(2) .* numslices;
      if (~isempty(iscl)),
         for j=1:1:length(iscl),
            istrt = 1+ (iscl(j)-1).*NperBrik;
            istp = istrt + NperBrik - 1;
            V(istrt:istp) = V(istrt:istp) .* facs(iscl(j));
         end
      end
   end

%if required, reshape V
	if(~DoVect),
		V = reshape(V, Info.DATASET_DIMENSIONS(1), Info.DATASET_DIMENSIONS(2),...
							numslices, numframes);
	else
		V = reshape(V, Info.DATASET_DIMENSIONS(1).* Info.DATASET_DIMENSIONS(2).* numslices, numframes);
	end

   
err = 0;
return;

%test code
clear all
Opt.Slices=[2 8];
Opt.Frames=[1 2];

BrikName='./r1_time+orig.BRIK';
[err, V, Info, ErrMessage] = BrikLoad(BrikName);
size(V)
figure(1);
k=0;
for i=1:2
   for j=1:2
      k=k+1;
      subplot(2,2,k);
imagesc(V(:,:,Opt.Slices(i),Opt.Frames(j))); 
if (exist('spectral')) colormap(spectral); end
colorbar;
end
end

clear all
Opt.Slices=[2 8];
Opt.Frames=[1 2];


BrikName='./r1_time+orig.BRIK';
[err, V, Info, ErrMessage] = BrikLoad(BrikName, Opt);
figure(2);
k=0;
for i=1:2
   for j=1:2
      k=k+1;
      subplot(2,2,k);
imagesc(V(:,:,i,j)); colormap(spectral); colorbar;
end
end