My plot is not showing a line? Why?

%Plot of net energy,attractive energy and repulsive energy of a two
%isolated ions seperated by a distance
% r is interatomic distance between the ions
clc; clear;
A=1.436; B=7.32*10^-6; n=8;
r = 0:0.1*10^-9:1*10^-9;
Net_Energy = zeros(length(r),1);
Attractive_Energy = zeros(length(r),1);
Repulsive_Energy = zeros(length(r),1);
for i=1:length(r)
    
  Net_Energy(i) = -A/r(i) + B/r(i)^n;
  Attractive_Energy(i) = -A/r(i);
  Repulsive_Energy(i) = B/(r(i)^n);
  
end

for i=1:length(r)

 plot(r(i),Net_Energy(i),'g')
 hold on
 plot(r(i),Attractive_Energy(i),'g')
 hold on
 plot(r(i)*10^9,Repulsive_Energy(i),'g')
 hold on
end

Answer 1

[Eddie]

Replace this

for i=1:length(r)
plot(r(i)*10^9,Net_Energy(i),'g')
hold on
end

with

f=figure; ax=axes(f); 
plot(ax,r*10^9,Net_Energy,'g');

If you want to plot a line, the data need to be a single input to plot function instead of using a for loop, which would only plot your data points as individual points.

[Frederick Anokye]

I have edit my code check again and comment

[Eddie]

Remove the for loop, use this instead

plot(r,Net_Energy,'g')
hold on %only need to do it once
plot(r,Attractive_Energy,'g')
plot(r*10^9,Repulsive_Energy,'g')

However, the last plot (Repulsive_Energy) won't appear with the other plots in the same region (since ther previous two plots are in region r, while the last one is in region r*10^9. I suspect this is what you want -

plot(r*10^9,Net_Energy,'g')
hold on %only need to do it once
plot(r*10^9,Attractive_Energy,'g')
plot(r*10^9,Repulsive_Energy,'g')

Answer 2

[Walter Roberson]

Remove the plotting loop and use

plot(r*10^9,Net_Energy,'g')

[Frederick Anokye]

Still not working

Answer 3

[Frederick Anokye]

Thanks!

How can I make the lines curvy

[Frederick Anokye]

How can I label the lines

[Walter Roberson]

use semilogy() instead of plot() to make the lines curvy.

To label the lines, use legend()