How to optimize this for loop?

% % % % --------------------
for i=1:size(v0)
   
        if (v0(i)<=2)
            v0(i) = 0;
        else
            if  (v0(i) >= 12 && v0(i) <= 25)
                v0(i) = 12;
            else
                if (v0(i) >= 26)
                v0(i) = 0;
                end
            end
        end
end
% condition for another wind speed
for i=1:size(v0)
    
        if (v1(i)<=2)
            v1(i) = 0;
        else
            if  (v1(i) >= 12 && v1(i) <= 25)
                v1(i) = 12;
            else
                if (v1(i) >= 26)
                v1(i) = 0;
                end
            end
        end
end
% conditon for another wind didrection
for i=1:size(v0)
    
        if (v2(i)<=2)
            v2(i) = 0;
        else
          if  (v2(i) >= 12 && v2(i) <= 25)
                v2(i) = 12;
            else
                if (v2(i) >= 26)
                v2(i) = 0;
                end
            end
        end
end

Answer 1

[Bob Thompson]

v0(v0<=2) = 0;
v0(v0>=26) = 0;
v0(v0>=120) = 12;

Should work for all three, because they're apparently the same with different labels? If they're all the same size I would strongly suggest avoiding using dynamically named variables. You can just concatenate them into a single matrix with another dimension. For example, if they are a single dimension, then they combine to a 2D matrix that you can loop through the second dimension on (not that you have to because you're looking for the same conditions and outputs. Then you only have to use the above code once, instead of three times.