======= Question and Answers - Web Log =======


===== How do I start? =====

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

===== 1st Problem: =====


**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



===== How do I plot? =====

**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.**


====Class project 1, Problem 2====
I think I've found where to turn off the CNO cycle: line 246 of src/star_controls.f.

===== Does anyone know how to turn off the CN, ON, or pp-chain cycles? =====

--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