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matlabstructureintersect

operations with structure in matlab


I have a structure 1x300 called struct with 3 fields but I'm using only the third field called way. This field is, for each 300 lines, a vertor of index.

Here an exemple with 3 lines to explain my problem : I woud like to search if the last index of the first line is present in an other vector (line) of the field way.

way
[491751 491750 491749 492772 493795 494819 495843 496867]
[491753 491754 491755 491756]
[492776 493800 494823 495847 496867]

I tried with intersect function :

Inter=intersect(struct(1).way(end), struct.way);

but Matlab returns me an error :

Error using intersect (line 80)
Too many input arguments.

Error in file2 (line 9)
Inter=intersect(struct(1).way(end), struct.way);

I don't understand why I have this error. Any explanations and/or other(s) solution(s)?


Solution

  • Let the data be defined as

    st(1).way = [491751 491750 491749 492772 493795 494819 495843 496867];
    st(2).way = [491753 491754 491755 491756];
    st(3).way = [492776 493800 494823 495847 496867]; % define the data
    sought = st(1).way(end);
    

    If you want to know which vectors contain the desired value: pack all vectors into a cell array and pass that to cellfun with an anonymous function as follows:

    ind = cellfun(@(x) ismember(sought, x), {st.way});
    

    This gives:

    ind =
      1×3 logical array
       1   0   1
    

    If you want to know for each vector the indices of the matching: modify the anonymous function to output a cell with the indices:

    ind = cellfun(@(x) {find(x==sought)}, {st.way});
    

    or equivalently

    ind = cellfun(@(x) find(x==sought), {st.way}, 'UniformOutput', false);
    

    The result is:

    ind =
      1×3 cell array
        [8]    [1×0 double]    [5]
    

    Or, to exclude the reference vector:

    n = 1; % index of vector whose final element is sought
    ind = cellfun(@(x) {find(x==st(n).way(end))}, {st([1:n-1 n+1:end]).way});