Error plotting graph, with y behaving similar to step function

Hi, i want to plot a graph where y=t^2 when t>0 and y=5 when t<0 giving that t=[-5:0.1:5]

t=[-5:0.01:5]

for i=length(t)

    if t<0
        y(i)=5;
    else if t>0
            y(i)=t^2;

        end
    end
end

this doesnt seem to work, it gave me an error that y is undefined. What did I do wrong

Answer 1

[Mischa Kim]

You could use something like

 t  = [-5:0.01:5];
 y  = (t.^2).*(t>0) + 5*(t<=0);
 yy = 5*ones(numel(t),1);
 yy(t>0) = t(t>0).^2;
 plot(t,y,t,yy)

showing two different approaches. As for your code, try

 t = [-5:0.01:5];
 for i=1:length(t)     % compute y for all t
    if t(i)<0          % need to compare each component of t 
        y(i) = 5;
    else
        y(i) = t(i)^2; % assign y component-wise 
    end
 end
 plot(t,y)

[Samious]

thanks Kim, :D