My plot comes up as a white graph with no line.

My homework is like that,

This is about dynamic voltage stability, I can't code this equation. After that I eliminate T, because it is constant, then just calculate PR. I want to draw t,PR and t,VR graph. But i can't. Please help me.

This question says Vr changes 1-0.9-1-1.05-1 respectively. then calculate Pr for T=1 and T<1,T>1.

Thank you from now.

When I try to plot with this code which is given below, nothing comes up. There are no errors, there's just nothing. I know, I only asking to draw one point at a time, so the plot has no information about which points should be connected. But i am new at Matlab, i can't able to draw graphic, please help me.

Expected graphic is like that,

clear all;
clc;
G=3;

t1=1:5
VR1=1;
PR1=G*VR1^2;


t2=5:15
VR2=0.9;
PR2=G*VR2^2;


t3=15:25;
VR3=1;
PR3=G*VR3^2;


t4=25:35;
VR4=1.05;
PR4=G*VR4^2;


t5=35:40;
VR5=1;
PR5=G*VR5^2;

hold on, plot(t1,VR1)
plot(t2,VR2)
plot(t3,VR3)
plot(t4,VR4)
plot(t5,VR5)
xlabel('t(1/100)'); ylabel('VR'); 
title('PR Değişimi');
grid on

Answer 1

[Image Analyst]

Give it a line style, like

plot(t, PR1, 'b.-', 'LineWidth', 3, 'MarkerSize', 30);

but the real problem is your PR are just scalars, not vectors, so there is not another point to draw the line between. Your PR do not depend on t, just VR, which is another scalar, so your result is a scalar.