How do I use a for loop on ever element in an array?

I need to use the if and elseif statements to modify the original values in the d array and spit out the new array according to the statements inside. Long story short how do I get an array back from a for loop? a needs to be the modified array.

d =([8 4 0.5 -3]);
for a = 1:length(d)
    if d<0
        d(a) = 2*cosd(d);
    elseif d <= 0 & d <= 1
        d(a) = 5*(d)^(1/3);
    elseif d < 1 & d < 7
        d(a) = ceiling(1/factorial(d));
    elseif d >= 7
        d(a) = 20*log(d)*(log10(d));
    end
end

Answer 1

[Jess Lovering]

I think that the below code is what you are asking about. Your if requirements seem like they may be off, however, so I changed those as well. And there is no function called "ceiling" but I put in ceil which is a rounding up command that you may be looking for.

d =([8 4 0.5 -3]);
for ii = 1:length(d)
    if d(ii)<0
        a(ii) = 2*cosd(d(ii));
    elseif d(ii) >= 0 & d(ii) <= 1
        a(ii) = 5*(d(ii))^(1/3);
    elseif d(ii) > 1 & d(ii) < 7
        a(ii) = ceil(1/factorial(d(ii)));
    elseif d(ii) >= 7
        a(ii) = 20*log(d(ii))*(log10(d(ii)));
    end
end

[Bryce Johnson]

Ah yes thank you very much that did solve it, it came up with the wrong answers but that was not your fault, I wrote the problem down wrong. You did help me get the function working though I appreatie that!