MATLAB Answers

Assigning a variable to any value in a matrix

141 views (last 30 days)
roram
roram on 27 Apr 2016
Commented: dpb on 27 Apr 2016
Hi,
I am having trouble on a project involving matrices.
An example with simplified but similar code:
Matrix = [0 1 4; 4 1 3];
for x = 1:10
if x + y == 5
My goal is to have y be ANY value in the original matrix, so the if statement is true if x + ANY Matrix Value is equal to 5.
Is this possible without using an extra for loop?
Thanks!

Answers (3)

Star Strider
Star Strider on 27 Apr 2016
Edited: Star Strider on 27 Apr 2016
You came close to answering it yourself. There is an any funciton.
Experiment with this to see if it does what you want:
Matrix = [0 1 4; 4 1 3];
y = Matrix;
for x = 1:10;
logic = any(x + y == 5)
end
EDIT To see the results of the comparison for different values of ‘x’, tweak the code to store the values, and display them in an array:
Matrix = [0 1 4; 4 1 3];
y = Matrix;
for x = 1:10;
logic(x) = nnz(any(x + y == 5));
end
Result = [[1:10]', (logic > 0)']
Result =
1 1
2 1
3 0
4 1
5 1
6 0
7 0
8 0
9 0
10 0

Jon
Jon on 27 Apr 2016
Try this
for x = 1:10
if sum(x + Matrix(:) == 5) > 0
disp(x)
end
end
  2 Comments
dpb
dpb on 27 Apr 2016
There are multiple possible locations...but, use logical array or find or the like--
>> x=1; % define an example x
>> (x+Matrix==5) % logical array
ans =
0 0 1
1 0 0
>> [i j]=find(x+Matrix==5); % return locations
>> disp([i j])
2 1
1 3
>>
Again, need more detail on what your end result is to be to have any real definitive implementation suggestions.

Sign in to comment.


dpb
dpb on 27 Apr 2016
Matrix = [0 1 4; 4 1 3];
for x = 1:10
if any(x+Matrix(:)==5)
...
NB: use of : to treat array as a vector such that any will return a single result.
You could possibly eliminate the loop entirely depending on what the resulting operation is.

Tags

Community Treasure Hunt

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

Start Hunting!