# MATLAB: Argggh! My equation isn’t plotting right with a for loop!!!

for loop

Greetings all,
This is probably trivial and overlooking a minor detail, but I have the following code, and I think my problem is that I have to start at zero somewhere:Response_values= 0:0.1:2;phiv=zeros(size(Response_values));for n=1:length(Response_values)    if Response_values(n)<2.1        phiv(n)=(4*n)/((4*n.^2+1).^3/2)    else        phiv(n)=0;    endendplot(Response_values,phiv);
As it is right now, "n" isn't being indexed right, therefore my plot is wrong. I know as of right now it starts at 1 and goes to 21. I wanted the equation to go from 0 to 2 in .1 increments. I know in MATLAB you can't start at an index of zero, so I searched these boards and tried to code the above.
Any help would be appreciated.
Thanks! -J

Response_values= 0:0.1:2;phiv=zeros(size(Response_values));for n=1:length(Response_values)  rValue = Response_values(n);    if rValue < 2.1        phiv(n)=(4*rValue)/((4*rValue.^2+1).^3/2)    else        phiv(n)=0;    endendplot(Response_values,phiv);grid on;xlabel('Response Value', 'FontSize', 20);ylabel('phiv', 'FontSize', 20);