iCosmo Source Code

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
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Adam Amara
Posts: 18
Joined: September 25 2004
Affiliation: ETH
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iCosmo Source Code

Post by Adam Amara » October 06 2008

The Source code for iCosmo is publicly available on the web and can be reached through the iCosmo website (http://www.icosmo.org). The source code is in IDL and the package is designed to be modular and extendable and can calculate all (or at least most) of the cosmological quantities relevant at low redshifts (z~< 10). Help documents and videos are also available.

As an example, the code is able to calculate cosmic shear (weak lensing) powerspectra as well Fisher matrix predictions for future surveys. These lensing calculations have been rigorously tested against many other codes.

Comments and discussion are very welcome.

Boud Roukema
Posts: 84
Joined: February 24 2005
Affiliation: Torun Centre for Astronomy, University of Nicolaus Copernicus
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iCosmo Source Code

Post by Boud Roukema » November 17 2008

If you want people to be able to contribute to your code and use it as a freely cooperating community without legal problems, I would suggest at least two things:

(1) Add a licence to the package, e.g. see gnu.org/licenses/licenses.html for a discussion of some of the various possible free (GPL compatible or GPL non-compatible) and non-free licences, e.g. GPL would be the obvious licence, but it's something to discuss among participants and decide on. If you say nothing about licensing, that does not make it public domain. By default, the authors hold a conventional copyright on their contributions. In principle, nobody is allowed to redistribute original or improved versions of icosmo unless they specifically contact all of you (the authors) and get your agreement every time. Just because it's on the web doesn't make it "public domain".

(2) You've presented your package to be used with a non-free software package called "IDL". This, for example, makes it potentially illegal (at least in the USA, maybe not in the EU) for people to write their own programs which read or write IDL "save/restore" files, at least according to the wikipedia entry on IDL: IDL Save/Restore files embody unpublished proprietary information about the IDL program. Reverse engineering of this file is therefore forbidden under the terms of the IDL End User License Agreement. ... Non-RSI supplied software that reads or writes files in the IDL Save/Restore must have a license from Research Systems explicitly granting the right to do so. ...

If you want to free people from this sort of constraint and encourage normal scientific collaboration, I would suggest that you test your program using the GNU Data Language (GDL). GDL is protected under the GPL, so anybody can essentially do just about anything with it they like (use it, modify it, redistribute it, distribute modified copies) on the condition that they give the same freedoms to other users, i.e. they keep the same licence. My guess is that it wouldn't take much effort to check, and in the long term, there's more of a chance that this would become a community tool.
The Source code for iCosmo is publicly available on the web...
As it stands at the moment, a more precise description is that your package is publicly available but non-free and recommends the use of a non-free programming package.

Adam Amara
Posts: 18
Joined: September 25 2004
Affiliation: ETH
Contact:

iCosmo Source Code

Post by Adam Amara » November 25 2008

The source code is publicly available through the iCosmo site. For those with access to an IDL license, please enjoy.

For people without access to an IDL license we will be continually updating the website interface to give you maximum flexibility. We are also working on a GDL compatible version, but this may take some time and any help on this will be welcome.

thanks,

Adam

Boud Roukema
Posts: 84
Joined: February 24 2005
Affiliation: Torun Centre for Astronomy, University of Nicolaus Copernicus
Contact:

Re: iCosmo Source Code

Post by Boud Roukema » December 01 2008

Adam Amara wrote:The source code is publicly available through the iCosmo site. For those with access to an IDL license, please enjoy.
I interpret that to mean that you have good intentions (of which I have no doubt :), but that doesn't seem to give any authorisation for modification or redistribution or redistribution of modified copies. The latter three rights are key elements (numbers 1, 2 and 3) of the notion of free (as in speech) software.
For people without access to an IDL license we will be continually updating the website interface to give you maximum flexibility. We are also working on a GDL compatible version, but this may take some time and any help on this will be welcome.
Cool. :)

However, I would expect you might have more chance of people contributing corrections if you made the licence clearer. i'm not making any promises to contribute, but if i'm not even allowed to modify my own copy of the code (which is the case at the present, given the absence of any clear licence), it would be rather difficult for me to test any modifications, and with the lack of a right to redistribute modified copies, I might not even be allowed to give you back my modified version!

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