CosmoBox - CAMB and CosmoMC ready to go

[Antony Lewis]

CosmoBox is a fully configured virtual machine, with everything you need to build and debug in Fortran 90, set up to go with CAMB and CosmoMC:




See http://cosmologist.info/CosmoBox/

Comes set up for full integrated visual debugging using Photran: no more write statements!

I'd be interested in thoughts and feedback. Esp. if anyone wants to do a comparison of CosmoMC runs embedded in the box compared to running natively (the virtualization overhead for CAMB is small, less than 10% on my machine). Note however that gfortran is usually around 20% slower than ifort.

Might also be useful to add some further software, e.g. gui Octave, gsl, or even WMAP.

[Savvas Nesseris]

I haven't tried it yet, but I think it's a good idea.

However, wouldn't it be better if CosmoBox was a live distro that one could run of a USB stick or portable hard drive?

This way you can avoid the virtualization overhead which is critical for a resource intensive program like cosmomc.

Cheers,
Savvas

[Antony Lewis]

Thanks for the suggestion. At the moment this is mainly aimed at development, where you are unlikely to want to re-boot to switch programs. In seamless mode you can use programs on the box much like any other program installed natively on your computer.

The virtualization overhead for CPU use is actually very low (modern chips have hardware virtualization), though I haven't tried a direct comparison of CosmoMC+MPI inside the box compared to running natively.

But the main point is that virtualization is what makes it hardware independent - if you try to produce native bootable images in general you'd have to do it for every possible hardware configuration you want to boot on; the idea of the virtual machine is to abstract the physical hardware so that one box will run on almost anything without any additional configuration (driver installation, etc).

[Henry Lin]

Hi Antony,
Perhaps commonly used preconfigured makefiles (for example wmap likelihood) should be included in Cosmobox to save time for users installing them.

[Sheng Li]

Hi Antony,
Perhaps commonly used preconfigured makefiles (for example wmap likelihood) should be included in Cosmobox to save time for users installing them.

Let me say sth.

Makefile used for compiling likelihood is almost the same as it is used for camb or mcmc program. You can copy them and comment out some lines, say

DR71RG

or
others out layers.

Simply, users can just update their compilers and MKL libraries. And all of these are used in your Makefile for both camb and CosmoMC program.

If i missed sth, ask antony.