MATLAB: Cant see the line in the plot

plotproblem

for H=200:100:36000 %For loop created for the Height of the satellite
Gc = 398000.5 %Gravitational Constant times Earth's Mass
Re = 6371 %Radius of Earth
V = sqrt(Gc/(Re+H)) %Formula for calculating the Satellite Speed
hold on %Allows to plot multiple times on the same graph
plot(H, V,'-b') %Plot the Height with respect the Speed
end
ylabel('Orbital Speed (Km/S)'), xlabel('Height (Km)') %Labels on each axis
grid on %Grid added for easier understanding of data
My code works but i dont get the plot line when i run this..

Best Answer

Don't use plot if you are trying to plot each H vs V value. Use Scatter
for H=200:100:36000  
    Height(H) = H;
    Gc = 398000.5;                                                           %Gravitational Constant times Earth's Mass
    Re = 6371;                                                               %Radius of Earth
    V = sqrt(Gc/(Re+H));                                                     %Formula for calculating the Satellite Speed
    scatter(H, V);    
    hold on                                                                 %Allows to plot multiple times on the same graph
                                                                            %Plot the Height with respect the Speed
end
ylabel('Orbital Speed (Km/S)'), xlabel('Height (Km)')                       %Labels on each axis
grid on
A more effifient way, and the better answer is this:
clear all;
figure;
Gc = 398000.5;                                                        
Re = 6371;
cntr = 1;
for H=200:100:36000
    V(cntr) = sqrt(Gc/(Re+H))
    Height(cntr) = H;
    cntr = cntr + 1;
end
plot(Height,V)
ylabel('Orbital Speed (Km/S)');
xlabel('Height (Km)');
grid on;
The problem in your script is that you are plotting a single point, rather than a set of x&y values. Scatter plots a single point better.
The second bit of code is most likely what you are looking for.
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