Remove NaN from matrix

Question

israel cohen 2024-6-5

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2125796-remove-nan-from-matrix

回答： Voss 2024-6-5

Hi All

this is my code:

% Read the CSV file into a table
Data = readtable(L2);
% Define the desired oridN numbers and phase
desired_oridN = [1, 3, 7, 16, 19, 21, 22, 24, 27, 28];
desired_phase = 'P';
% Initialize cell arrays to store Azimuth values for each oridN
all_azimuths = cell(1, length(desired_oridN));
% Iterate over all rows in the table
for i = 1:height(Data)
    % Check if the current row's oridN is in the desired list
    idx = find(desired_oridN == Data.oridN(i));
    if ~isempty(idx) && strcmp(Data.phase{i}, desired_phase)
        % Store Azimuth value for the corresponding oridN
        all_azimuths{idx} = [all_azimuths{idx}; Data.Azimut(i)];
    end
end
% Convert cell array to matrix
max_length = max(cellfun(@numel, all_azimuths));
azimuth_matrix = NaN(max_length, length(desired_oridN));
for i = 1:length(desired_oridN)
    azimuth_matrix(1:numel(all_azimuths{i}), i) = all_azimuths{i};
end

i get NaN values in each columns because my columns not in the same length and this is ok. How can i evoid this?

Thank you!!

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Voss 2024-6-5

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2125796-remove-nan-from-matrix#answer_1468046

In a matrix, all columns are the same length. That's one of the defining characteristics of matrices. You're not going to be able to have a matrix whose columns are different lengths.

If you want to store column vectors of different lengths in a matrix, then you'll need to use NaNs or some other placeholder value to fill out the columns and make them all the same length in the matrix.

If you want to store column vectors of different lengths without any placeholder values, then store them in a cell array, exactly as you already have in your all_azimuths variable.