Adding private num2cell.

kern/private/num2cell.m

@@ -0,0 +1,74 @@
+function c = num2cell(a,dims)
+%NUM2CELL Convert numeric array into cell array.
+%   C = NUM2CELL(A) converts numeric array A into cell array C by placing
+%   each element of A into a separate cell in C. The output array has the
+%   same size and dimensions as the input array. Each cell in C contains
+%   the same numeric value as its respective element in A.
+%
+%   C = NUM2CELL(A, DIM) converts numeric array A into a cell array of
+%   numeric vectors, the dimensions of which depend on the value of the DIM
+%   argument. Return value C contains NUMEL(A)/SIZE(A,DIM) vectors, each of
+%   length SIZE(A, DIM). The DIM input must be an integer with a value from
+%   NDIMS(A) to 1.
+%
+%   C = NUM2CELL(A, [DIM1, DIM2, ...]) converts numeric array A into a cell
+%   array of numeric arrays, the dimensions of which depend on the values
+%   of arguments [DIM1, DIM2, ...]. Given the variables X and Y, where
+%   X=SIZE(A,DIM1) and Y=SIZE(A,DIM2), return value C contains
+%   NUMEL(A)/PROD(X,Y,...) arrays, each of size X-by-Y-by-.... All DIMn
+%   inputs must be an integer with a value from NDIMS(A) to 1.
+%
+%   NUM2CELL works for all array types.
+%
+%   Use CELL2MAT or CAT(DIM,C{:}) to convert back.
+%
+%   See also MAT2CELL, CELL2MAT
+
+%   Clay M. Thompson 3-15-94
+%   Copyright 1984-2022 The MathWorks, Inc.
+
+narginchk(1,2);
+if nargin==1
+    if isa(a, 'function_handle')
+        c = {a};
+        return
+    end
+    c = cell(size(a));
+    for i=1:numel(a)
+        c{i} = a(i);
+    end 
+    return
+end
+
+% Size of input array
+siz = [size(a),ones(1,max(dims)-ndims(a))];
+
+% Create remaining dimensions vector
+rdims = 1:max(ndims(a),max(dims));
+rdims(dims) = []; % Remaining dims
+
+% Size of extracted subarray
+bsize(sort(dims)) = siz(dims);
+bsize(rdims) = 1; % Set remaining dimensions to 1
+
+% Size of output cell
+csize = siz;
+csize(dims) = 1; % Set selected dimensions to 1
+c = cell(csize);
+
+% Permute A so that requested dims are the first few dimensions
+a = permute(a,[dims rdims]); 
+
+% Make offset and index into a
+offset = prod(bsize);
+ndx = 1:prod(bsize);
+try
+    for i=0:prod(csize)-1,
+        c{i+1} = reshape(a(ndx+i*offset),bsize);
+    end
+catch E
+    % This should never happen!
+    error('unexpected:num2cell', ...
+        'Unexpected error in num2cell. size(a): [%s]; dims: [%s]; offset: %d; ndx: [%s];  i: %d; error: %s', ...
+        strjoin(string(size(a))), strjoin(string(dims)), offset, strjoin(string(ndx)), i, getReport(E));
+end