Question and Answers - Web Log

Let's assume everyone has the code installed. I also assume that everyone knows how to get to the directory EZ_3_6_3.

Change to directory 'src':

cd src

Open file dispatch.f:

emacs dispatch.f

You need to change this file so it looks as follows:

    PROGRAM dispatch
    USE demo1
    USE demo2
    USE ez_example
    CALL Do_Example
    END PROGRAM dispatch

Save and close it

Open ez_example.f:

    emacs ez_example.f &

In there you find the lines to change metalicity and the mass:

For z = 0.02:

    metals_dir = '../metals/z02' ! metallicity -- use z0001, z0003, z001, z004, z01, z02, or z03

Change the mass:

    mass = 25D0  ! initial mass -- anything from 0.3 to 100

Change the output frequency to make nicer plots, and suppress repeated header

Add the lines

    head_cnt = 100000
    summary_cnt = 1

after the line

    CALL Init_Do_One_Utils(mass)

After you did the changes save and go to the directory 'make'. Type:

    make

Now it should compile everything.

When it's done go to the directory 'run' and type:

    ./EZ

You see an output on your screen. To redirect this output to a textfile:

    ./EZ > textfile.txt

This textfile contains a table of values which you will use to plot the evolution of the star.

if you'd like to see the output while copying it into he text file, you can use the `tee` command by “pipelining” the output as input to the `tee` command using `|`

    ./EZ | tee textfile.txt

Repeat for z = 0.001:

    metals_dir = '../metals/z001' ! metallicity -- use z0001, z0003, z001, z004, z01, z02, or z03

Stay in the directory where your textfile.txt is.

Open textfile.txt to see which values are in which column.

    emacs textfile.txt &

Open the plotting program gnuplot:

    gnuplot

To plot, type:

    set terminal jpeg
    set output "stemperature.jpeg"
    set xrange [*:*]
    set yrange [*:*]
    set xlabel "Log age (yr)"
    set ylabel "Log surface temperature (K)"
    plot '0.02.txt' using 7:6 with lines, '0.001.txt' using 7:6 with lines
    reset

In this case, '0.02.txt' is the textfile for z = 0.02 and '0.001.txt' for z = 0.001. 'using 7:6' specifies which columns you want to plot. Column 7 corresponds to the age and column 6 to the surface temperature. For other plots change the 6 to whatever column you want to plot over time.

You will find the plot 'stemperature.jpeg' in the directory you are in.

I think I've found where to turn off the CNO cycle: line 246 of src/star_controls.f.

–Mark Zastrow

In ez_nuclear_data.f you can find how the different reactions are named. You can then edit them in ez_nuclear.f

So for example to turn off the He3 + He3 reaction, change R33 = RHB*RRT(2)/2D0 into R33 = 0 !RHB*RRT(2)/2D0

–Andrea