How to use looping

I have a coding like this:

for k=1:length(Depth)

if Depth(k)>0 & Depth(k)<=6

RdFk(k) = -0.0425 .*Depth(k)+1.0333

elseif Depth(k)>6 & Depth(k)<12

RdFk(k) = 0.0006 .*(Depth(k))^2 + 0.0048.*(Depth(k))+0.7865

elseif Depth(k)>=12 & Depth(k)<=15

RdFk(k) = -0.02.*Depth(k) + 1.06

else Depth(k)>16 & Depth(k)<=30

RdFk(k) = -0.0025.*(Depth(k))^2+0.072.*(Depth(k))+0.261

end

end

Why the coding only read the last else (last criteria i.e. RdFk(k) = -0.0025.*(Depth(k))^2+0.072.*(Depth(k))+0.261 ) and pass through other criteria?

Thx

Answer 1

[David Hill]

You might want to eliminate your loop.

RdFk=zeros(size(Depth));
RdFk(Depth>0&Depth<=6)  = -0.0425*Depth(Depth>0&Depth<=6)+1.0333;
RdFk(Depth>6&Depth<=12) =  0.0006*(Depth(Depth>6&Depth<=12)).^2 + 0.0048*(Depth(Depth>6&Depth<=12))+0.7865;
RdFk(Depth>12&Depth<=15) = -0.02*Depth(Depth>12&Depth<=15) + 1.06;
RdFk(Depth>15&Depth<=30) = -0.0025*(Depth(Depth>15&Depth<=30)).^2+0.072*(Depth(Depth>15&Depth<=30))+0.261;

[Skydriver]

I change the zero with ones and it works now

Thank you