How to change 0 to 1 and update a matrix

Question

Antonio Grivas 2019-6-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/468230-how-to-change-0-to-1-and-update-a-matrix

回答： Antonio Grivas 2019-6-22

clc
clear all
close all
b1 = [10; 20 ; 30 ; 40];
A = [0 20 0 10 ; 20 0 30 0 ; 0 30 0 10 ; 20 0 10 0];
s = size(b1);
x = randi([0 1],s)
G = [];
[ n m ] = size(x);
for i = 1 : n
    for j = 1 : m
    G(:,i) = x(:,j)
    a = find(G(: , i) == 0 , 1 , 'first')
    [x y] = size(G(:,i))
    for k = 1:y
        G(: , k) = 0;
        G(a , k) = 1
    end
    end
    i = i + 1;
    j = j + 1;
end

This prob wil work only the first time. I want the matrix to take a column, find where the first 0 is and change it to 1. Then proceed to the next line and do the same but keep the first column and not change it to 0s. Final solution must look like

(x changes randomly with 0 and 1 )

G =
   0     0     0
   1     0     0
   0     1     0
   0     0     1

I would appreciate any answer :)

5 个评论
显示 3更早的评论隐藏 3更早的评论

Stephen23 2019-6-21

编辑：Stephen23 2019-6-21

在 MATLAB Online 中打开

@Antonio Grivas: Whenever I run your code it always returns this:

It is unclear how this output relates to your examples.

Please explain the logic of what you are trying to achieve.

Antonio Grivas 2019-6-21

It is completely wrong. I don't know how to make it change the final result whick would be

1

0

1 0

0 1

0 0

1 0 0

0 1 0

0 0 1

0 0 0

1 0 0 0

0 1 0 0

0 0 1 0

0 0 0 1

I send the (without the wrong loop) answer where the program runs correctly only the first time

I suppose that i need a

for i = 1:size(whatever)

whatever(: , i) = 0

whatever(: , a) = 1

end

that sould be put somewhere to keep the previous results and not change it back to

0

and change the position of the 1 after adding a column

If you run it just check only the 1st time before it changes it back to

0

1

0

becomes

0 1

0 0

1 0

0 0

Then for some reason that i cannot see does not continue but gives

0 4

I am trying to be precise if i can to help you

Thank you

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Andrei Bobrov 2019-6-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/468230-how-to-change-0-to-1-and-update-a-matrix#answer_380222

编辑：Andrei Bobrov 2019-6-22

在 MATLAB Online 中打开

n = numel(x1);
y1 = ~x1;
% if MATLAB >= R2016b
k = y1.*eye(n);
% if MATLAB <= R2016a
k = bsxfun(@times,y1,eye(n));
out = [x1, zeros(n,n-1)];
p = find(y1);
out(:,2:numel(p)+1) = k(:,p);