合并第二到最后一列以复制第一列中的重复项 [英] Merge 2nd to last columns for duplicates in 1st column

问题描述

如果A的第一列重复，我想将A的第二列合并到结束列

I want to merge A's 2nd to end column if A's 1st column is duplicate

来自

A = [2 3 1;
     3 4 2;
     2 6 8]

到

B{1}=2 3 1 6   8
B{2}=3 4 2 NaN NaN

或

B = [2 3 1 6    8;
     3 4 2 NaN NaN]

行排序无关紧要.

我的第一个计划是

A=sortrows(A,1); % sort by 1st col

然后根据第一列将A划分为各种矩阵(即，不同的第一列元素使用不同的矩阵)

and then divide A into various matrices according to 1st col (i.e. different matrix for different 1st column element)

然后horzcat每个矩阵的每个2:end元素.

then horzcat each 2:end elements for each matrices.

，然后以某种方式将它们连接到一个对象中.

and then join them into one object in some way.

这只是我的计划或想象力，尽管我不知道这是否可行.

This is simply my plan or imagination though I can't figure out if this is possible.

推荐答案

以下是一种使您入门的方法.它将使用0而不是NaN填充:

Here is a method to get you started. It will pad with 0 instead of NaN though:

B = sortrows(A,1);
C = B(1,:);    

for row = 2:size(B,1)
    if B(row,1) == C(end,1)
        C(end, end+1:end+2) = B(row, 2:3);
    else
        C(end+1, 1:3) = B(row, :);
    end
end

或者您可以使用单元格数组执行相同的操作，而不必完全填充:

Or you could do the same thing using a cell array and not have to pad at all:

B = sortrows(A,1);
C = {B(1,:)};    

for row = 2:size(B,1)
    if B(row,1) == C{end}(1)
        C{end}(end+1:end+2) = B(row, 2:3);
    else
        C{end+1} = B(row, :);
    end
end

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