• Nov 20th 2009, 11:57 AM
elninio
I have no experience with this sort of problem.

I've only ever made simple graphs before. This one requires special computer software.

For now, the problem is simple...

I have derived a formula for a simple model of a star:

\$\displaystyle P=P_0 (r/r_0)^a\$ ; \$\displaystyle T=T_0 (r/r_0)^b\$

I need to make a graph of a vs b.

This is where I'm begging you to help me. What (free) program could I use? Could anyone provide instructions on how to graph this with the program?

I thank you very very much in advance!
• Nov 20th 2009, 12:42 PM
CaptainBlack
Quote:

Originally Posted by elninio
I have no experience with this sort of problem.

I've only ever made simple graphs before. This one requires special computer software.

For now, the problem is simple...

I have derived a formula for a simple model of a star:

\$\displaystyle P=P_0 (r/r_0)^a\$ ; \$\displaystyle T=T_0 (r/r_0)^b\$

I need to make a graph of a vs b.

This is where I'm begging you to help me. What (free) program could I use? Could anyone provide instructions on how to graph this with the program?

I thank you very very much in advance!

Plot what against what? Are you sure you want a against b?

CB
• Nov 20th 2009, 12:46 PM
elninio
Positive. In these equations, r is radius, and r0, P0, and T0 are all positive constants. This is keeping in mind that the temperature, pressure, and density all decrease with radius.

After I graph it, I'll have to point out three regions of the graph (convectively stable, unstable and non-physical)