Create a new vector

Hello everyone!

I have a problem but I can solve it. I would like to create a new vector with using if statement in a for loop. The problem is I dont' know how to call the new vector last member in the if statement. I know the first member the new vector. The first member is xn1.

I would like that if the if statement is true than add fn the last member the new vector. If false the new member is equal the last member.

I hope somebody can help me. Thanks a lot!

xn1=0.6;
xs=0.9:0.3:30;
fn=0.5;
fs=0.3;
r1=0.8;
r2=0.4;
xn=[];
for i=1:lenght(xs)
if (xs(i)+fs-r2)>=(xn(i-1)+fn/2)
    % if true xn last member + fn 
    xn(i)=xn(i-1)+fn
else 
    % if false xn not change
     xn(i)=xn(i-1)
end
end

Answer 1

[David Hill]

xn1=0.6;
xs=0.9:0.3:30;
fn=0.5;
fs=0.3;
r1=0.8;
r2=0.4;
xn=0;
for i=1:lenght(xs)
  if (xs(i)+fs-re2)>=(xn(i)+fn/2)%have no idea what re2 is
    xn(i+1)=xn(i)+fn;%cannot index xn(0)
  else 
    xn(i+1)=xn(i);
  end
end

[Zsolt Illés]

I corrected it re2 is r2. Thanks a lot. Now it's working