For Loop plot range of numbers

Hello,

I'm trying to plot this equation:

Then use gamma as 1.4, 1.3, and 1.2.

And have n_n (eta_n) as a varied range of numbers: [ 1.00 0.975 0.975 0.950 0.925]

But with the code I kept trying to manipulate, I keep getting just one plot, and it's the wrong plot as well. Please, any advise will help.

the graph is supposed to be including all the eta_n. Each of them. Then the varied gammas are seperate. So, I should end up with three graphs, one for each gamma value, each having four curves (eta_n)

The graph is supposed to look like something like this: (if gamma = 1.3)

%gamma 
g1 = 1.4;
g2 = 1.3;
g3 = 1.2;
%eta_n
n = [1.00 0.975 0.975 0.950 0.925];
%pt2/p_inf
p = 100;
%Me
M = linspace(1,10,15);
%Ae/A* for g = 1.4
for N = 1:numel(n)
A_1(n) = ((1./M).*((2/(g1+1)).*(1+((g1-1)./2).*M.^2).^((1/2).*((g1+1)./(g1-1))))).*((1+(1-(1./(n))).*((g1-1)./2).*M.^2).^(-g1/(g1-1)));
hold on
loglog(A_1(n),M);
xlabel('A_e/A*');
ylabel('M_e');
grid on
legend('eta_n=1.00','eta_n=0.975','eta_n=0.950','eta_n=0.925');
end

Answer 1

[Star Strider]

I cannot follow what you are doing.

At the very least, the ‘A_1’ assignment needs to be:

A_1(N,:) = ((1./M).*((2/(g1+1)).*(1+((g1-1)./2).*M.^2).^((1/2).*((g1+1)./(g1-1))))).*((1+(1-(1./(n(N)))).*((g1-1)./2).*M.^2).^(-g1/(g1-1)));

so the entire code becomes:

%gamma
g1 = 1.4;
g2 = 1.3;
g3 = 1.2;
gv = [g1, g2, g3];                                      % Optional, If You Want To Cycle Through Them Later
%eta_n
n = [1.00 0.975 0.975 0.950 0.925];
%pt2/p_inf
p = 100;
%Me
M = linspace(1,10,15);
%Ae/A* for g = 1.4
for N = 1:numel(n)
    A_1(N,:) = ((1./M).*((2/(g1+1)).*(1+((g1-1)./2).*M.^2).^((1/2).*((g1+1)./(g1-1))))).*((1+(1-(1./(n(N)))).*((g1-1)./2).*M.^2).^(-g1/(g1-1)));
    hold on
    loglog(A_1(N,:),M);
    xlabel('A_e/A*');
    ylabel('M_e');
    grid on
    legend('eta_n=1.00','eta_n=0.975','eta_n=0.950','eta_n=0.925');
end

That produces one Warning about the legend entries, and otherwise runs without error.

[Hailey]

Hi,

Your code comes out as the below graph. I had this show up before for me too.

[Hailey]

Look at my question edit, and maybe that could help?

[Star Strider]

I cannot detect any errors in your code (or my edit of it).

There is obviously something ‘over the horizon’ that we can’t see.

I will delete my Answer later, since it does not appear to be one.

Answer 2

[Andrei Bobrov]

g = reshape(1.4:-.1:1.2,1,1,[]);
n = [1.00, 0.975, 0.975, 0.950, 0.925];
M = linspace(1,10,15)';
g1 = g + 1;
g_1 = g - 1;
A = 1./M.*(2./g1.*(1+g_1./2.*M.^2)).^(.5*g1./g_1).*(1+(1-1./n).*g_1/2.*M.^2).^(-g./g_1);

[Hailey]

Hi Andrei,

Where would I submit this edit in my current code? Woud it go before the for loop? Thanks in advance.