Your T is a vector, and your Y is a scalar. There is no singular line because it is actually plotting all 5 points as individual line objects. check it out:
figure
Yo= 2012500;
K= 8050000;
r= 0.71;
t= 2;
Y= (K*Yo)./((K-Yo)*exp(-r*t)+Yo);
T= 0:0.5:t;
a= plot(T,Y,'ro')
The above code should plot 5 circular markers.
a will return 5 line objects.
if you ran this:
% here, both arguments are of the same size.
% All I did was repeat Y n number of times equal to the length of T
a= plot(T,repmat(Y,1,numel(T)),'r')
then a will return 1 line object, that is a line.
also, dont put a space between plot and the parentheses.
let me know if this clears your question
