How to create an original matrix by using non zero value indices?

A = [1 0 0 0 1;

1 0 0 0 1 ;

1 0 0 0 0;

1 0 0 0 0;

1 0 0 0 0];

[R1 C1] = size(A); %% Size of A is 5 x 5

[X, Y] = find(A);

P = [X, Y];

P = [ 1 1;

2 1;

3 1;

4 1;

5 1;

1 5;

2 5];

[R2 C2] = size(P); %% Size of P is 7 x 2

How to create an original matrix (A) of the size 5 x 5 by using non zero value indices of variable P of the size 7 x 2 and remaining indices values are zero.

Answer 1

[yanqi liu]

sir, may be use the follows code

clc; clear all; close all;
A = [1       0       0        0          1;
    1      0         0         0         1 ;
    1        0         0         0         0;
    1        0         0         0         0;
    1        0         0         0         0];
%% Size of A is  5 x 5
[R1, C1] = size(A);          
[X, Y] = find(A);
P = [X, Y];
P   =      [ 1     1;
    2     1;
    3      1;
    4      1;
    5      1;
    1       5;
    2      5];
%% Size of P is  7 x 2
[R2 C2] = size(P);          
%% gen matrix
B = zeros(max(P(:,1)), max(P(:,2)));
loc = sub2ind(size(B), P(:,1), P(:,2));
B(loc) = 1;
disp(B)
isequal(A, B)

you can read the book 《计算机视觉与深度学习实战》

     1     0     0     0     1
     1     0     0     0     1
     1     0     0     0     0
     1     0     0     0     0
     1     0     0     0     0


ans =

  logical

   1

>> 

[SUKUMAR NAGINENI]

Dear yanqi liu

Thank you so much sir for your help,

you can read the book 《计算机视觉与深度学习实战 , This textbook link is not available on any website in India. If possible, kindly share the link to the soft copy of the book.

Thanks & regards

Sukumar.