How to start a plot on the same axis at a different value?

Hi guys,

I am trying to plot two different linear equations functions and the sum of the two together. However, I would like to have one of the lines to start from zero when x=2 instead of when x=0. The resultant linear plot of the sum of the two functions that I am seeking should be equal to the function (y) until function (y1) starts at 2 and it would then decrease and become negative (since y1 decreases at a higher rate).

I hope it is clear enough my expalnation of what I am trying to do.

This is the code I have used.

x=0:1:24;

y=2*x;
y1=-4*(x-2);
r=y+y1;

plot(x,y,x,y1,x,r)
grid on
legend('y','y1','r')

Thank you in advance

Answer 1

[David Hill]

x=0:1:24;
y=2*x;
y1=-4*(x-2);
y1(1:2)=0;%y1=0 when x<2 (if you change the x vector you will need to change this
r=y+y1;
plot(x,y,x,y1,x,r)
grid on
legend('y','y1','r')