converts a cell array into a matrix
FORMAT [x] = pr_spm_cat(x,d);
x - cell array
d - dimension over which to concatenate [default - both]
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Empty array elements are replaced by sparse zero partitions
and single 0 entries are expanded to conform to the non-empty
non zero elements.
e.g.:
> x = pr_spm_cat({eye(2) []; 0 [1 1; 1 1]})
> full(x) =
1 0 0 0
0 1 0 0
0 0 1 1
0 0 1 1
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Copyright (C) 2005 Wellcome Department of Imaging Neuroscience
0001 function [x] = pr_spm_cat(x,d) 0002 % converts a cell array into a matrix 0003 % FORMAT [x] = pr_spm_cat(x,d); 0004 % x - cell array 0005 % d - dimension over which to concatenate [default - both] 0006 %__________________________________________________________________________ 0007 % Empty array elements are replaced by sparse zero partitions 0008 % and single 0 entries are expanded to conform to the non-empty 0009 % non zero elements. 0010 % 0011 % e.g.: 0012 % > x = pr_spm_cat({eye(2) []; 0 [1 1; 1 1]}) 0013 % > full(x) = 0014 % 0015 % 1 0 0 0 0016 % 0 1 0 0 0017 % 0 0 1 1 0018 % 0 0 1 1 0019 %__________________________________________________________________________ 0020 % Copyright (C) 2005 Wellcome Department of Imaging Neuroscience 0021 0022 % Karl Friston 0023 % $Id: spm_cat.m 258 2005-10-18 18:21:07Z karl $ 0024 0025 % check x is not already a matrix 0026 %-------------------------------------------------------------------------- 0027 if ~iscell(x), return, end 0028 0029 % if concatenation over a specific dimension 0030 %-------------------------------------------------------------------------- 0031 [n m] = size(x); 0032 if nargin > 1 0033 0034 % concatenate over first dimension 0035 %---------------------------------------------------------------------- 0036 if d == 1 0037 y = cell(1,m); 0038 for i = 1:m 0039 y{i} = pr_spm_cat(x(:,i)); 0040 end 0041 0042 % concatenate over second 0043 %---------------------------------------------------------------------- 0044 elseif d == 2 0045 0046 y = cell(n,1); 0047 for i = 1:n 0048 y{i} = pr_spm_cat(x(i,:)); 0049 end 0050 0051 % only viable for 2-D arrays 0052 %---------------------------------------------------------------------- 0053 else 0054 error('uknown option') 0055 end 0056 x = y; 0057 return 0058 0059 end 0060 0061 % find dimensions to fill in empty partitions 0062 %-------------------------------------------------------------------------- 0063 for i = 1:n 0064 for j = 1:m 0065 if iscell(x{i,j}) 0066 x{i,j} = pr_spm_cat(x{i,j}); 0067 end 0068 [u v] = size(x{i,j}); 0069 I(i,j) = u; 0070 J(i,j) = v; 0071 end 0072 end 0073 I = max(I,[],2); 0074 J = max(J,[],1); 0075 0076 % sparse and empty partitions 0077 %-------------------------------------------------------------------------- 0078 [n m] = size(x); 0079 for i = 1:n 0080 for j = 1:m 0081 if isempty(x{i,j}) 0082 x{i,j} = zeros(I(i),J(j)); 0083 elseif ~x{i,j} 0084 x{i,j} = zeros(I(i),J(j)); 0085 else 0086 x{i,j} = full(x{i,j}); 0087 end 0088 end 0089 end 0090 0091 % concatenate 0092 %-------------------------------------------------------------------------- 0093 for i = 1:n 0094 y{i,1} = cat(2,x{i,:}); 0095 end 0096 x = sparse(cat(1,y{:}));