add all the same-sized symbol matrices in a cell array

adding matrices inside cell array

Actually, the same-sized numeric matrices in a cell array can be easily summarized by using

% Create dummy input
c = {[1 2; 3 4], [3 3; 1 1]}
c = 
    [2x2 double]    [2x2 double]
% Elementwise sum across matrices (only if ALL matrices have same size)
sum(cat(3,c{:}),3)
ans =
     4     5
     4     5

However, it does not work for symbol matrices in a cell.

syms x
q = [x,2*x,3*x;sin(x),cos(x),tan(x);exp(x),2^x,log(x)];
c = arrayfun(@(i)q,(1:10)',...
    'UniformOutput' ,false);
sum(cat(3,c{:}),3)

错误使用 symengine
    Arguments must be 2-dimensional.
    出错 sym/privUnaryOp (line 1036)
                Csym = mupadmex(op,args{1}.s,varargin{:});
    出错 sym/sum (line 85)
        s = privUnaryOp(A, 'symobj::prodsumdim', num2str(dim), '_plus');

Here the function is used for this purpose. Although matlab fixed the bug in 2021a and later.

We have

b = symCellSum(a)

And then the answer is obtained

b =
 
[      10*x,      20*x,      30*x]
[ 10*sin(x), 10*cos(x), 10*tan(x)]
[ 10*exp(x),    10*2^x, 10*log(x)]

Enjoy for whose matlab version lower than 2020a