[Objcryst-announce] ObjCryst++ 1.02 available
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vincefn
From: Vincent Favre-N. <vi...@us...> - 2001-12-01 10:39:57
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A new version of ObjCryst++ is available. ObjCryst++ is an object-oriented crystallographic computing library. It allows easy definitions of high-level objects such as Crystal, atomic scattering power, Scatterers (Atoms, molecules using ZMatrix, Polyhedra), scattering data objects (PowderPattern with background and multiple crystalline phases, basic SingleCrystal data), as well as Global Optimization algorithms. Optionaly, it can provide a cross-platform Graphical User Interface for all objects ; this has been used for the Fox program. By using inheritance for scatterer and scattering data objects, the library ensures its expandability to new type of scatterer description, and scattering experiments. Plus, all objects are 'optimization-ready': all objects in the library automatically declare structural parameters (atom positions, temperature factors, profile widths, bond angles...) and "costfunctions" (such as R, Rw for diffraction data, antibump cost function for Crystals...) in a generic way. The advantage of such an approach is that instead of having an all-knowing algorithm at the top, which must know and understand the purpose of all parameters, all objects (Crystals, Atoms, molecules, ScatteringPowers, ScatteringData) define their parameters in the same way: thus any parametrization change in (say) a temperature factor will automatically be taken into account by the algorithm. All objects can also declare "cost functions" (eg R, Rw, Antibump,...) in the same generic way and any combination of these cost functions can be used by global opptimization algorithms. Currently available are Simulated Annealing and Parallel Tempering. The library also features an optional graphical user interface for all objects using the cross-platform library wxWindows, with a display of structural parameters for all objects, powder patterns, and interactive 3D view (using OpenGL) of crystal structures. For a demonstration of these features you can try the Fox program. The entire project was written in ISO c++ and requires a recent compiler. It has been tested under Linux (using gcc 2.95.3+) and windows (using the free Borland compiler bcc 5.5). This library, is open-source and is available from SourceForge : http://objcryst.sourceforge.net and on the CCP14 mirrors (thanks to Lachlan Cranswick): http://www.ccp14.ac.uk/ccp/web-mirrors/objcryst/ http://ccp14.sims.nrc.ca/ccp/web-mirrors/objcryst/ http://ccp14.semo.edu/ccp/web-mirrors/objcryst/ The library has been developped in the Laboratory of Crystallography in Geneva, and development is going on (currently with major modifications for the algorithms objects) after my move to the ESRF. It is possible to access the latest source code by using the CVS repository on SourceForge. -- Vincent Favre-Nicolin ESRF http://v.favrenicolin.free.fr/ |