# Limiting range of a matrix

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Kamil Kacer on 26 Dec 2022
Commented: DGM on 26 Dec 2022
I have matrix A = [1 2 3 4 5 6 7 8];
I try to limit the matrix to numbers greater than 3 and less than 6 how do I do it ?
I use this line but it assigns numbers less then 3 to 3 and numbers greater then six to six. Instead i want to eliminate those numbers in matrix which dont belong in this range.
max(min(A,3),6)

Karim on 26 Dec 2022
Edited: Karim on 26 Dec 2022
You can use logical indexing to obtain such a result, see below for a demonstration
A = [1 2 3 4 5 6 7 8];
% define the limits
maxValue = 6;
minValue = 3;
% use logic to find the indexes
idx = A >= maxValue | A <= minValue;
% set the values we don't want to zero
A(idx) = 0
A = 1×8
0 0 0 4 5 0 0 0
it is off course also possible to do this in a single line:
A = [1 2 3 4 5 6 7 8];
A(A>=6 | A<=3) = 0
A = 1×8
0 0 0 4 5 0 0 0
Voss on 26 Dec 2022
Edited: Voss on 26 Dec 2022
cl{m} = c{m}(c{m}>=0.5 | c{m} <= 0.05) ==0;
That's not assigning elements of c{m} to 0; it's comparing certain elements of c{m} to 0, then storing the result (of class logical, i.e., true/false) in cl{m}.
DGM on 26 Dec 2022
Note that zero is also an out-of-range value, so filling the elements with zero doesn't solve the problem of limiting the range of the array.
When someone asks "I want to arbitrarily remove elements from an array" one has to ask what "remove" means, because it's not obvious. You can't just remove any element from an array and retain the shape of the array. If you want to fill the missing elements with some value, the value that you use depends entirely on your needs and the class of the array. So what exactly are your expectations?

Torsten on 26 Dec 2022
A = [1 2 3 4 5 6 7 8];
A(A<3) = 3;
A(A>6) = 6;
A
A = 1×8
3 3 3 4 5 6 6 6