how to fix invalid first data argument

n=1;

for ii=1:0.5:9

t(n)=ii;

if ii>=0

y(n)=-3*ii.^2+5;

n=n+1;

elseif ii<0

y(n)=3*ii.^2+5;

n=n+1;

end

end

plot(t,y)

Answer 1

[Star Strider]

Your code runs without error for me.

Note that in your code ‘ii’ is never going to be less than 0, so the entire if block is not necessary.