RAMSES Halo finder - what are folks using?

[Rick Sarmento]

What halo finders are folks using with large RAMSES cosmological simulations. I find the included HOP finder crashes when hop and regroup generate files at 4.1GB ... which I suspect is a limit. [It's actually poshalo that crashes on the 'tag' file generated by regroup.]

I've also tried to compile rockstar without success... it appears to want some older rpc/type.h and rpc/xdr.h includes that I can't seem to find on the supercomputer I'm using. A version of pFoF I have also seems to die with MPI errors after reading in the particle files. 

Anyway, what are folks using?

Rick

[Corentin CADIOU]

Hey Rick,

I’ve had some experience in the past using rockstar, adaptahop (https://ascl.net/1305.004) and ahf.

Regarding rockstar, it is indeed annoying to get working. I have now packaged it in anaconda, which means you can install it easily using conda install -c conda-forge rockstar-galaxies. This should make rockstar-galaxies available in your path!

If you install a recent version of yt-astro-analysis, rockstar is now installed alongside and you can run the finders directly using yt. That’s actually what people in the AGORA collaboration have been using.

For AHF, you need to convert the RAMSES dataset into a Gadget-like format. If you’re interested, I can provide some scripts to achieve this.

I hope that helps,
Best,
Corentin

--
You received this message because you are subscribed to the Google Groups "ramses_users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ramses_users...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/ramses_users/cbea1289-f4f8-43fa-9dd1-705a7bc32c57n%40googlegroups.com.

-- 
Dr. Corentin Cadiou
Post Doctoral Research Assistant
Lund University
mobile: +33.6.43.18.66.83

[Romain Teyssier]

Hi Rick,

You can also try and use the Ramses clump finder called PHEW (see Wiki on BitBucket).

It does a good job at finding halos and subhalos with some caveats.

Romain

[Rick Sarmento]

Thanks so much Corentin,  

Sure: I'd love to adapt your scripts to get RAMSES -> Gadet for AHF. I'll prob have to make some mods to the conversion since I've added 2 extra scalar fields to the particles in RAMSES ... (the follow 'metal' in the output file so it's usually pretty easy to tell a piece of code to ignore them). 

So -- I'm not sure I can use the yt version unmodified (I know yt can deal with extra scalars in RAMSES output, but can the integrated halo finder?!!??!).

I'll also like to try and build/install rockstar. Again -- I'll prob have to download, modify and then install the version you have packaged up to work with my tweaked version of RAMSES.

Thx again!

Rick

[Rick Sarmento]

Hi Romain,

Thanks -- yeah I should have looked into clumpfinder before running my simulation for 2+ weeks. LOL ... I'll check the docs but I believe I'd have to re-run the simulation, correct?

Best,

Rick

[Romain Teyssier]

You can restart and turn on the clump finder for the next snapshots.

To view this discussion on the web visit https://groups.google.com/d/msgid/ramses_users/5c2d63bf-0621-4bcf-9611-6badc9c91f83n%40googlegroups.com.

[Rick Sarmento]

Oh ok... so it'll find 'clumps' going forward! Good to know.

Thanks Romain.... Cheers,

Rick