Clear Filters
Clear Filters

A compact way to assign values of a matrix to another matrix

17 views (last 30 days)
How to assign the values of matrix "x" to the matrix "y" in a, possibly, single line of code?
% Input
x = [3 2 2; 4 5 3; 6 5 4; 4 6 5; 5 6 6; 6 6 7];
y = logical([0 0 0; 1 1 1; 1 1 1; 1 1 1; 1 1 1; 1 1 1; 1 1 1]);
% Desired Output
>> y
Invalid use of operator.
y =
0 0 0
3 2 2
4 5 3
6 5 4
4 6 5
5 6 6
6 6 7
% My attempt
>> y(find(y))=x
y =
7×3 logical array
0 0 0
1 1 1
1 1 1
1 1 1
1 1 1
1 1 1
1 1 1
  4 Comments
Stephen23
Stephen23 on 13 Jun 2023
"How to assign the values of matrix "x" to the matrix "y" in a, possibly, single line of code?"
Given that matrix y is of logical type, all non-zero values will be cast into TRUE values. Is that what you want?
Sim
Sim on 13 Jun 2023
@Stephen23, thanks for the comment!! No, I do not want that all non-zero values will be cast into true values. I would like this (I just converted the logical matrix into a numerical matrix):
x = [3 2 2; 4 5 3; 6 5 4; 4 6 5; 5 6 6; 6 6 7];
y = ([0 0 0; 1 1 1; 1 1 1; 1 1 1; 1 1 1; 1 1 1; 1 1 1]);
y(y~=0)=x
y = 7×3
0 0 0 3 2 2 4 5 3 6 5 4 4 6 5 5 6 6 6 6 7

Sign in to comment.

Accepted Answer

Dyuman Joshi
Dyuman Joshi on 13 Jun 2023
Edited: Dyuman Joshi on 13 Jun 2023
Since y is a logical array, any values assigned to it will be converted to corresponding logical value.
Convert y into double and then assign -
%Modified x, x(1,2) is 0.
x = [3 0 2; 4 5 3; 6 5 4; 4 6 5; 5 6 6; 6 6 7];
y = logical([0 0 0; 1 1 1; 1 1 1; 1 1 1; 1 1 1; 1 1 1; 1 1 1]);
%temporary variable
y1 = y;
%assigning to logical
%You can see how assignment is done to logical array
%0 is assigned as 0 and any other value is 1
y1(y1) = x
y1 = 7×3 logical array
0 0 0 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
%convert to double
z = double(y)
z = 7×3
0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
%and assign
z(y)=x
z = 7×3
0 0 0 3 0 2 4 5 3 6 5 4 4 6 5 5 6 6 6 6 7

More Answers (1)

Sim
Sim on 13 Jun 2023
Edited: Sim on 13 Jun 2023
Sorry, stupid question... I had a logical matrix "y" and I got what I wanted, just by assigning a numerical array instead of a logical one:
x = [3 2 2; 4 5 3; 6 5 4; 4 6 5; 5 6 6; 6 6 7];
y = ([0 0 0; 1 1 1; 1 1 1; 1 1 1; 1 1 1; 1 1 1; 1 1 1]);
y(y~=0)=x
y = 7×3
0 0 0 3 2 2 4 5 3 6 5 4 4 6 5 5 6 6 6 6 7

Categories

Find more on Creating and Concatenating Matrices in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!