FARGO

Benchmarking

Frederic Masset — 2010-10-22T03:54:48Z

Here are quoted a few speed up ratios between GFARGO, and the standard, double precision FARGO code on one CPU core. These speed up ratios are obtained in the limit of a large mesh. In the case of the comparison problem of de Val-Borro et al. (2006), the small size of the mesh (384*128) yields somewhat smaller ratios. The CPU code, for these benchmarks, is always compiled with gcc, with the -O3 and -ffast-math options.
The standard test of a Neptune mass planet embedded in an inviscid disk (...) - GFARGO

Interactive commands

Frederic Masset — 2010-10-22T03:54:32Z

You can press the following keys while running the windowed version (built with make win) to change the code's behavior:
key 'd' : plot the density field
key 'r' : plot the radial velocity field
key 't' : plot the azimuthal velocity field (residual with respect to Keplerian velocity).
key 'v' : plot the vortensity field
Space bar key : pause / restart
key 'u' : toggle update.
key 'f' : toggle fullscreen
key 'c' : toggle Cartesian / polar representation (disabled in fullscreen mode) (...) - GFARGO

FAQ

Frederic Masset — 2010-10-22T03:54:19Z

Is there a difference with the output format of the CPU version ?
There are two main differences:
the hydrodynamics fields, that are written in raw format, are now written in single precision rather than double precision. They occupy half the disk space that they would occupy with the CPU version. Under IDL, they should be read in arrays defined with fltarr, rather than dblarr.
The azimuthal velocity (written to the files gasvtheta*.dat) is now the residual velocity with respect to (...) - GFARGO

Overview

Frederic Masset — 2010-10-22T03:54:01Z

The GPU version of FARGO (GFARGO) is written in C and C for CUDA. It runs only on NVIDIA's graphics cards. It should be regarded essentially as a "proof of concept". It corresponds to the standard, isothermal version of FARGO, although not all the functionnalities of the CPU version have been translated to CUDA. Namely, the following features are absent from the GPU version:
Gas accretion onto the planets
MPI communications. This version is therefore mono-GPU only.
The -e command line (...) - GFARGO

Download

Frederic Masset — 2010-10-22T03:53:46Z

Important note 1
Whereas the installation of the standard version of FARGO is a breeze, the installation of GFARGO (FARGO for GPU) is significantly more tricky. You should make sure that you first know how to install and run the standard CPU version, as the directories structure and output format is essentially the same. The installation of the standard CPU version is explained here.
Important note 2
Before you can install GFARGO, you must install the three packages provided by NVIDIA, (...) - GFARGO

IDL tools : rep.pro

Jules Casoli — 2009-09-28T15:22:47Z

The routine rep.pro is used to display the data, with a lot of options. Start by typing : rep,dir="out2",noutput=5,"density" which should display the density field over the whole disc, in a polar (r,phi) representation, at the fifth output (hence, 5 orbits in you ran the template2.par file provided) : As rep.pro internally calls open.pro, you can change density to whatever you like (pressure, vortensity, etc.). For a detailed list of the possibilities of this command, you should consult (...) - IDL

IDL tools : open.pro

Jules Casoli — 2009-09-28T15:22:40Z

This routine opens the gas*.dat file created by FARGO, to produce arrays containing any desired quantity, such as density, pressure, temperature, entropy, vorticity, etc.
To open the output files produced during output #1, type, for example : open,dir="out2",noutput=1,density=d1,vrad=vr1 tvscl,vr1
dir, and noutput being sticky, if you now want to open other quantities, you can just type : open,vorticity=v1,radii=rad,azimuths=az radii and azimuths being arrays containing the radial and (...) - IDL

IDL tools : tqf.pro

Jules Casoli — 2009-09-28T15:22:08Z

This routine plots the torque output by FARGO, as a function of time (in orbits). You can call it from the exact directory where the data is (i.e. " /your_fargo_dir/out2"). For example, from your fargo directory, issue : cd,"out2" tqf You should see this : As we don't want to have to type cd each time we want an other torque plot, we can place ourselves in our FARGO directory, from where we still can call tqf : cd,".." tqf,dir="out2" If you want another torque on top of this, from another (...) - IDL

IDL tools

Jules Casoli — 2009-09-28T15:00:02Z

News 2010-12 : Some cleanup has been made. You can see the (small) changes here.
A set of tool is available for opening and displaying easily the files output by FARGO in IDL. GDL users, see the note
Download and install You can download it here. To install, simply uncompress it in your FARGO directory. This should create an "idl" directory, containing 10 routines. Include this directory in IDL's path, by editing the startup file (defined by the environment variable IDL_STARTUP)
(To do so, (...) - IDL

First run

Aurélien Crida — 2009-01-16T15:47:33Z

To start your first run, after compiling, enter the following command line in the parent directory of the in/, out/, and src/ directories : ./fargo2D1D in/template.par
This makes the simulation of a Jupiter mass planet initially on a circular orbit at r=1, in a disk extending from 0.04 to 20. The 2D grid extends from 0.35 to 2.5 (but the rings between 0.35 and 0.4 and between 2.45 and 2.5 are ghosts). The rest is covered by the 1D grid. The resolution is $\delta r=0.01$
The aspect ratio is (...) - FARGO-2D1D