For this lesson you will need:
Solar mass stars are fine, but get a little boring after a while. Let's make a whole set of models that we can use if we want to look at the evolution of other stars.
Let's take a look at the data file. It looks like this:
This file differs from the previous one in that we have changed a few of the input parameters. As we've already evolved our star down to the main sequence, we now set NCH=2 as we don't need to reset the composition. In addition, we've also changed IX (the third number to the right of NCH) to zero. This allows energy to be generated without hydrogen being used up as we want the models we create to still be on the ZAMS. We've also changed the frequency at which the code saves detailed models to modout, by setting NSAVE=50 (the penultimate nubmer on the third line). It is important to do this as we're going to want to use the output models as input for future runs and we want to get a reasonable spread in masses. And now for the important bit -- we've also set RMG to 1.00E-5 (in the middle of the fourth line from the botttom). This will add mass to the model. It is important to check that the timestep times RMG isn't too great (i.e. is less than about 0.1 in practice) otherwise the code will not converge as it tries to add too much mass in one go. If necessary, you can reduce either RMG, or the timestep in the modin.
If you run the above, you should be able to create a set of models up to about 150 solar masses in a few hundred timesteps. You can keep track of the progress of the models either by plotting out the 6th column of the plot as you go, or by looking at the out file, where the second number in the first column gives the mass at the current timestep.