When using MATLAB accumarray, if the subscripts in `'subs'` are not sorted, the accumulating function ‘`fun`‘ should not depend on the order of the values in its input data. Otherwise you would have weird results. To show the input data for the accumulating function, one can define the function as ‘@(x){x}’. This would save the input data for you. For example,

>> val = 101:105;

>> subs = [1; 2; 4; 2; 4]

>> A = accumarray(subs, val, [], @(x){x})A =

[ 101]

[2x1 double]

[]

[2x1 double]