如何使我的索引函数更快？

Question

因此，给定一个结构数组 Index，其中包含字段、Word、文档、位置，它需要一个 char 数组的单元数组并将其索引到 Index 中，并记录索引出现的文档的 DocNums。

function Index = InsertDoc(Index, newDoc, DocNum)
    for i = 1:numel(newDoc) 
        contains = any(strcmpi(newDoc(i),[Index.Word]));
        if any(contains);
            curr = find(strcmpi(newDoc(i),[Index.Word]),true);
            Index(curr).Documents{1} = unique([Index(curr).Documents{1},DocNum]);
            if (numel(Index(curr).Documents{1}) ~= numel(Index(curr).Locations))
                Index(curr).Locations{end+1} = [i];
            else
                Index(curr).Locations{end} = [Index(curr).Locations{end},i];
            end

        else 
            curr = numel(Index) + 1;
            Index(curr).Word = [newDoc(i)];
            Index(curr).Documents = {DocNum};
            Index(curr).Locations = {[i]};
        end
    end
end

例如

Doc1 = {'Matlab', 'is', 'awesome'};
Doc2 = {'Programming', 'is', 'very', 'very', 'fun'};
Doc3 = {'I', 'love', 'Matlab','very','much};

someIndex = InitializeIndex;
% InitializeIndex just creates struct array with the given fields and empty cell arrays
someIndex = InsertDoc(someIndex, Doc1, 1);
someIndex = InsertDoc(someIndex, Doc2, 2);
someIndex = InsertDoc(someIndex, Doc3, 3);

结果将是 一些索引（1）

Word: 'Matlab'
Documents: [1 3]
Locations: {[1] [3]}

someIndex(2)

Word: 'is'
Documents: [1 2]
Locations: {[2] [2]}

someIndex(5)

Word: 'very'
Documents: [2 3]
Locations: {[3 4] [4]}

我需要能够使用包含 20000 个元素和各种单词的结构数组来运行它，而现在完成索引需要花费大量的时间。我该如何改进这个算法？

Answer 1

在循环开始之前尝试allocate memory 为您的元胞数组“Index”。