How do you rewrite the nested if statement as a loop?

for i=1:length(x)
    if x(i) >= -1 && x(i) <= -0.9
        count(1) = count(1)+1;
    elseif x(i) >-0.9 && x(i)<-0.8
        count(2) = count(2)+1;
    elseif x(i)>-0.8 && x(i)<-0.7
        count(3) = count(3)+1;
    elseif x(i)>-0.7 && x(i)<-0.6
        count(4) = count(4)+1;
    elseif x(i)>-0.6 && x(i)<-0.5
        count(5) = count(5)+1;
    elseif x(i)>-0.5 && x(i)<-0.4
        count(6) = count(6)+1;
    elseif x(i)>-0.4 && x(i)<-0.3
        count(7) = count(7)+1;
    elseif x(i)>-0.3 && x(i)<-0.2
        count(8) = count(8)+1;
    elseif x(i)>-0.2 && x(i)<-0.1
        count(9) = count(9)+1;
    elseif x(i)>-0.1 && x(i)<0
        count(10) = count(10)+1;
    elseif x(i)>0 && x(i)<0.1
        count(11) = count(11)+1;
    elseif x(i)>0.1 && x(i)<0.2
        count(12) = count(12)+1;
    elseif x(i)>0.2 && x(i)<0.3
        count(13) = count(13)+1;
    elseif x(i)>0.3 && x(i)<0.4
        count(14) = count(14)+1;
    elseif x(i)>0.4 && x(i)<0.5
        count(15) = count(15)+1;
    elseif x(i)>0.5 && x(i)<0.6
        count(16) = count(16)+1;
    elseif x(i)>0.6 && x(i)<0.7
        count(17) = count(17)+1;
    elseif x(i)>0.7 && x(i)<0.8
        count(18) = count(18)+1;
    elseif x(i)>0.8 && x(i)<0.9
        count(19) = count(19)+1;
    elseif x(i)>0.9 && x(i)<=1
        count(20) = count(20)+1;
    end
end

Answer 1

[Adam]

lowLims = -1:0.1:0.9;
highLims = -0.9:0.1:1;

count = sum( x > lowLims & x <= highLims );

should work though I replaced the < with a <= because e.g. 0.1 will not fall into any case. Maybe this is your intention, in which case just put the < back and it should still work.

Use vectorisation instead of a loop when you can, though it is fine to go via a loop first if it is easiest. Certainly you don't ever want a massive structure of it-else statements like yours though that is hard to maintain and liable to bugs as well as being unreadable.