通过Matlab重新排列

问题描述

A = [a 2 5 8;
     b 4 8 NaN]

其中a和b是1x3行向量.

我需要使用以下内容获取单元格数组B:

I need to get a cell array B with:

B{1}=2 a
B{2}=5 a
B{3}=8 a b
B{4}=4 b

顺序无关紧要.

所以我需要相对于那些1x3行向量a和b逐个元素地放置第4,5,6..th列，而不必考虑NaN.

So I need to put the 4,5,6..th columns element by element with respect to those 1x3 row vectors a and b, disregarding NaN.

我的第一次尝试是unique(A)，但仅此一项并不能消除NaN，也无法正确匹配.

My first try was unique(A), but this alone couldn't eliminate NaN, nor can it match correctly.

也许我还需要获取每个元素(2、5、8、4、8，)排"的索引矩阵，但是我找不到方法.

Perhaps I also need to get the index matrix of at which "row" each element (2,5,8,4,8,), but I couldn't find how.

然后我尝试使用for和if.但是我的电脑无法处理如此大的文件.

I then tried using for and if. But my PC was unable to process this with huge file size.

推荐答案

所以您有一个矩阵A:

A = [a 2 5 8;
     b 4 8 NaN];

我首先将矩阵分为a和b以及其余部分:

I'll first split the matrix into parts consisting of a and b and the rest:

a_and_b = A(:,1:3);
Arest = A(:,4:end);

然后，我们将看到此Arest矩阵中的唯一项，并删除NaN s:

then we'll see what the unique items are in this Arest matrix, and remove the NaNs:

Arest_uniq = unique(Arest);
Arest_uniq = Arest_uniq(~isnan(Arest_uniq));

检查Arest行中Arest_uniq中元素的出现情况:

check the occurences of the elements in Arest_uniq in rows of Arest:

occur_A = arrayfun(@(ii) ismember(Arest_uniq,Arest(ii,:)),1:size(A,1),'uni',false);

由于基于if构造添加a和/或b行不是线性操作，因此我宁愿循环执行.

Because adding those rows a and/or b based on an if-construction isn't a linear operation, I'd rather just do it in a loop.

output = num2cell(Arest_uniq);
for ii=1:numel(output)
    for jj=1:size(A,1)
        if occur_A{jj}(ii)
            output{ii} = [output{ii} a_and_b(jj,:)];
        end
    end
end

请通过步骤进行操作，分步调试，在途中检查变量，最终您将了解所有操作.因此，下次您可以亲自解决问题.

Go through this with step-by-step debugging, inspect variables on the way, and eventually you'll understand what everything does. So next time you can solve your problems yourself on the spot.

这篇关于通过Matlab重新排列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！