MATLAB: Comparing the array to two variables

arrays and comparing variables

Hello

I'm trying to compare my array values ( numerical ) to two variables. For example i would like any number in my array greater than 2 to be rounded to two, and any number less than 0 rounded to 0. I can't seem to find a simple expression to do this. So i would like to compare all numbers in the array to those two conditions and then round them to their respective closest number. How do i possible go about this?

Best Answer

% Generate random data between -3 and 3 
a = -3;
b = 3;
r = (b-a).*rand(100,1) + a;
r(r>2) = 2 ; % Change numbers greater then 2 
r(r<0) = 0 ;% Change numbers less then 0

Read about find, round, ceil, floor.

Related Solutions

MATLAB: How to do repeating numbers in array

An old fashioned way:

>> V = [1,0,0,0,2,0,0,0,3,0,0,0,0,0,5,0,0,0,0];
>> X = V~=0;
>> U = V(X);
>> U(cumsum(X))
ans =
   1   1   1   1   2   2   2   2   3   3   3   3   3   3   5   5   5   5   5

MATLAB: How to modify a matrix to change the entries >=0 and multiply it by 5 AND to change the entries <0 and add 2 to those entries

Start with "If an entry in B is greater than or equal to zero": You can either run a loop over all elements of B or use "logical indexing":

% Linear indexing:
for k = 1:numel(B)
   if B(k) >= 0
     ...
   end
end

Or two indices for rows and columns:

for r = 1:size(B, 2)
  for c = 1:size(B, 1)
    if B(r, c) >= 0
       ...
    end
  end
end

Or "logical indexing":

index = (B >= 0);
disp(B(index))

Now try to use this to modify B. Use the mentioned terms to search in the documentation and in the internet.

Best Answer

Related Solutions

MATLAB: How to do repeating numbers in array

MATLAB: How to modify a matrix to change the entries >=0 and multiply it by 5 AND to change the entries <0 and add 2 to those entries

Related Question