如何将数组分成矩阵中的不同行(Matlab) [英] How can I separate an array into different rows in a matrix (Matlab)

问题描述

我正在尝试使用For循环(或实际上任何有效的形式)构造一个NaN矩阵，该矩阵的一部分包含行作为数组

I am trying to construct a NaN matrix that has parts of an array as its rows using For Loops (or really any form that works)

例如:

W = [0 0 0 2 3 2 0 0 4 5 6 6 5 0 0 0 0 8 8 9 8 0 0 0 0 ... ]

每当由零引起的刹车时，我只想迭代数字而不迭代零，以使每当有数字再次被零分隔时，每次都会在我的新矩阵中形成新的一行，结果是:

whenever there is a brake caused by the zeros I want to iterate only the numbers and not the zeros in such that whenever there are numbers again separated by zeroes it forms a new row each time in my new matrix, resulting in:

Matrix = NaN(5) %just big enough to fit everything
Matrix =  [2 3 2 NaN NaN; 4 5 6 6 5;8 8 9 8 NaN] % and so forth

*我一直为此使用Nested For Loop，但仍然遇到错误. 预先谢谢你！

*I've been using a Nested For Loop for this but still getting errors. Thank you in advance!

推荐答案

这是不使用循环的解决方案.

Here is a solution without using loops.

W = [0 0 0 2 3 2 0 0 4 5 6 6 5 0 0 0 0 8 8 9 8 0 0 0 0];
W_idx = logical(W);
lbl = cumsum([diff([false W_idx]) > 0]) .* W_idx;
%lbl = bwlabel(W_idx) %use the image processing toolbox
count = accumarray(lbl(:)+1,1).';
count = count(2:end);
result_idx = (1:max(count)).' <= count ;
result = NaN(size(result_idx));
result(result_idx) = W(W_idx);
result = result.';

结果:

result =

     2     3     2   NaN   NaN
     4     5     6     6     5
     8     8     9     8   NaN

如果您需要数字索引，则可以为时间索引创建一个单独的数组:

If you need indices of numbers you can create a separate array for the time indices:

time_data = 1:25;
time_result = NaN(size(result_idx));
time_result(result_idx) = time_data(W_idx);
time_result = time_result.';

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