# plotting multiple coefficients of polynomial function

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Shane Palmer on 20 Jun 2020
Answered: Shane Palmer on 20 Jun 2020
Hello,
I have tried to follow the suggested examples for plotting multiple graphs on one figure of the same function with different coefficients.
I've been unsuccessful in my attempts. I am trying to model my function of omega and eta, but with multiple k values.
I started off trying to setup a for loop, but did not get that to work for me.
I tried to just define my k value multiple times and use the "hold on" command, but the graph just maintained the last value of k and excluded the previous k values.
I know I am missing something simple here, but I am not seeing it.
Here is my code:
syms omega__norm
k = 0.8;
eta__H = omega__norm*k.^2/(omega__norm.^2*(1-k.^2)+1)
fplot(omega__norm,eta__H,[10^-2 10^2])
set(gca,'Xscale','log')
hold off
Again, I would like setup k as a vector of values and plot all of the resulting graphs on a single figure.
Just not seeing how I need to do that properly.

#### 1 Comment

Shane Palmer on 20 Jun 2020
Oh, just figured it out. I needed a for loop like this:
syms omega__norm
for k = 0.5:0.05:0.9
eta__H = omega__norm*k.^2/(omega__norm.^2*(1-k.^2)+1)
fplot(omega__norm,eta__H,[10^-2 10^2])
hold on
end
set(gca,'Xscale','log')
hold off
Thought that I had tried that, but it works now, sorry for the hassle.

Shane Palmer on 20 Jun 2020
See comment above.