loglog plot at high numbers

Hi, I am having trouble plotting something in loglog plot.

I want to make a plot of n vs. T where n goes from 10^16 to 10^38 m^-3 and T goes 1 - 10^5 eV

And I have the equation 7.4 * sqrt (T/n);

How can I do this? I keep playing with the variables but I keep getting that my variable is too large etc.

Answer 1

[John D'Errico]

Must not be possible then. :)

n = 10.^(rand(1,100)*22 + 16);
T = 10.^(rand(1,100)*5);

loglog(T,n,'o')

[Benjamin Cowen]

but how do i plot it with my equation?

Answer 2

[Walter Roberson]

The equation 7.4 * sqrt (T/n) involves both of your input variables n and T, so you are effectively asking for a 3D plot rather than a 2D plot.

n = logspace(16, 38);
T = logspace(0, 5);
[Gn, GT] = ndgrid(n,T);
eqn = 7.4 * sqrt(GT./Gn);
surf(Gn, GT, eqn, 'edgecolor', 'none');
set(gca, 'XScale', 'log', 'YScale', 'log', 'ZScale', 'log')

but you will not find the coloring to be interesting because coloring is based upon the original values not upon log() of the values. You might prefer

surf(Gn, GT, log(eqn), 'edgecolor', 'none');
set(gca, 'XScale', 'log', 'YScale', 'log', 'ZScale', 'linear')