replacing rows with values from another matrix

Question

caroline bourn 2021-3-14

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/772888-replacing-rows-with-values-from-another-matrix

评论： caroline bourn 2021-3-17

Hi,

i have 1 3625 x 1 matrix. i have used the following code to flip values based on an index. It gives me a matrix of 1185x1. (as expected)

next =1;
% figure out origin and flip the x and y axis accordingly 
for i=1: length(pts)
    x_values = flip(x(next:pts(i))) % this finds the walks that start at the other side of origin
    next=pts(i);
end 

this gives me the output i expect.

now where i am having trouble is with replacing the values in my previous matrix with these new values....

pts is 1250, 2434, 3624.

the new matrix x_values is from pts 1250 - 2434.

2 个评论
显示无隐藏无

David Hill 2021-3-15

Not enough information to help. Showing sample of input and expected output would help. Your loop is over-riding x_values during each cycle of the loop. What does the pts() array look like?

caroline bourn 2021-3-16

expected.xlsx

pts is [ 1250, 2435, 3624] this is the change in time (indicating a new test)

i know it is over-ridding. i dont want it to... i want the expected output to look like this.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

ANKUR KUMAR 2021-3-16

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/772888-replacing-rows-with-values-from-another-matrix#answer_648817

在 MATLAB Online 中打开

Since you have not attached any speciific data, I am generating random values and indices to change.

clc
clear
original_mat=randi(20,1,100);
new_mat=randi(20,1,30);
index_to_change=45:74;
original_mat(index_to_change)=new_mat;

Hope this helps.

3 个评论
显示 1更早的评论隐藏 1更早的评论

ANKUR KUMAR 2021-3-17

在 MATLAB Online 中打开

clc
clear
[~, ~, raw] = xlsread('expected.xlsx','Sheet1','C1:D3624');
raw(cellfun(@(x) ~isempty(x) && isnumeric(x) && isnan(x),raw)) = {''};
cellVectors = raw(:,2);
raw = raw(:,1);
data = reshape([raw{:}],size(raw));
original_mat = data(:,1);
new_mat = cellVectors(:,1);
clearvars data raw cellVectors;
replace_index=cellfun(@(x) ~isempty(x) & isnumeric(x), new_mat);
original_mat(replace_index)=cell2mat(new_mat(replace_index));
updated_matrix=original_mat;

caroline bourn 2021-3-17

hi thank you for this! much appreciated. the problem is with this code i am writing it to apply to any file i get. the position of index relies on pts which in this particular case is calculated using find change pts. pts is [1250, 2435, 3624]. i also want to stay using text files.....

请先登录，再进行评论。