Metadata-Version: 1.1
Name: xrt
Version: 0.9.2
Summary: Ray tracing in x-ray regime, primarily meant for modeling synchrotron beamlines and beamline elements
Home-page: http://pythonhosted.org/xrt
Author: ('Konstantin Klementiev', 'Roman Chernikov')
Author-email: first DOT last AT gmail DOT com
License: MIT License
Description: 
        Package xrt (XRayTracer) is a python software library for ray tracing in
        x-ray regime. It is primarily meant for modeling synchrotron beamlines and
        beamline elements.
        
        Why another ray tracing program?
        --------------------------------
        
        Indeed, there are several good programs for ray tracing, like `Shadow`, `Ray`,
        `McXtrace`. These have been extremely useful in modeling synchrotron beamlines
        and/or individual beamline components. However, they all have the following
        drawbacks:
        
        * Limited graphical output, where the images are composed of dots representing
          individual rays. A color map, if ever implemented, can encode a physical
          property *not* weighted with intensity (unless it is intensity itself).
        
        * The choice of surface shapes is very limited. Closed shapes, like wave-guides
          or capillaries, are not possible.
        
        * Multiple reflections at a single surface, as it happens in a multi-bounce
          capillary, are not possible.
        
        * Non-sequential optical elements, as poly-capillaries or multi-mirror arrays,
          are not possible.
        
        * There are many restrictive limitations on energy range and energy mesh
          points, spatial mesh size etc.
        
        * The execution cannot be parallelized (except may be in `McXtrace`).
        
        The above issues are resolved in xrt.
        
        Features of xrt
        ---------------
        
        * *Publication quality graphics*. 1D and 2D position histograms are
          *simultaneously* coded by hue and brightness. Typically, colors represent
          energy and brightness represents beam intensity. The user may select other
          quantities to be encoded by colors: angular and positional distributions,
          various polarization properties, beam categories, number of reflections,
          incidence angle etc. Brightness can also encode partial flux for a selected
          polarization and incident or absorbed power. Publication quality plots are
          provided by `matplotlib` with image formats PNG, PostScript, PDF, SVG.
        
        * *Unlimited number of rays*. The colored histograms are *cumulative*. The
          accumulation can be stopped and resumed.
        
        * *Parallel execution*. xrt can be run in parallel in several
          threads or processes (can be opted), which accelerates the execution on
          multi-core computers. It can run on an external server (supercomputer), also
          without X window system (X11) support.
        
        * *Scripting in Python*. xrt can be run within Python scripts to generate a
          series of images under changing geometrical or physical parameters. The image
          brightness and 1D histograms can be normalized to the global maximum
          throughout the series.
        
        * *Sources*. xrt can have several light sources. For example, an ID beamline
          has 3 sources: one ID and two BM. This feature allows exploring the influence
          of out-of-focus sources.
        
        * Synchrotron sources. Bending magnet, wiggler,
          undulator and elliptic undulator are calculated internally within xrt. There
          is also a legacy approach to sampling synchrotron sources using the codes
          `ws` and `urgent` which are parts of XOP package. Please look the section
          `Comparison of synchrotron source codes` for the comparison between the
          implementations. If the photon source is one of the synchrotron sources, the
          total flux in the beam is reported not just in number of rays but in physical
          units of ph/s. The total power or absorbed power can be opted instead of flux
          and is reported in W. The power density can be visualized by isolines.
          Tapering of the magnetic gap has been added (0.9.2). Undulators can now be
          calculated on GPU, with a high gain in computation speed (0.9.2).
        
        * *Shapes*. There are several predefined shapes of optical elements implemented
          as python classes. The inheritance mechanism simplifies creation of other
          shapes. The user specifies methods for the surface and the surface normal.
          For asymmetric crystals, the normal to the atomic planes can be additionally
          given. The surface and the normals are defined either in local (x, y)
          coordinates or in user-defined parametric coordinates. Parametric
          representation enables closed shapes like capillaries. The methods of finding
          the intersections of rays with the surface are very robust and can cope with
          pathological cases like sharp surface kinks. Any surface can be combined with
          a (differently and variably oriented) crystal structure and/or (variable)
          grating vector. Surfaces can be faceted.
        
        * *Energy dispersive elements*. Implemented are crystals in dynamical
          diffraction,
          gratings (so far, without efficiency calculations), Fresnel zone plates and
          Bragg-Fresnel optics. Crystals can work in Bragg or Laue cases, in reflection
          or in transmission. The two-field polarization phenomena are fully preserved,
          also within the Darwin diffraction plateau, thus enabling the ray tracing of
          crystal-based phase retarders. As compared to XOP/Shadow, xrt works correctly
          for asymmetric crystals in transmission regime.
        
        * *Materials*. The material properties are incorporated using three
          different tabulations of the
          scattering factors, with differently wide and differently dense energy
          meshes. Refraction index and absorption coefficient are calculated from the
          scattering factors. Two-surface bodies, like plates or refractive lenses,
          are treated with both refraction and absorption.
        
        * *Multiple reflections*. xrt can trace multiple reflections in a single
          optical element. This is useful, for example in 'whispering gallery' optics
          or in Montel or Wolter mirrors. Here, very handy is the histogramming over
          the number of reflections, incidence angle and elevation over the surface.
        
        * *Non-sequential optics*. xrt can trace non-sequential optics where different
          parts of the incoming beam meet different surfaces. Examples of such optics
          are poly-capillaries and Wolter mirrors.
        
        * *Global coordinate system*. The optical elements are positioned in a global
          coordinate system. This is convenient for modeling a real synchrotron
          beamline. The coordinates in this system can be directly taken from a CAD
          library. The optical surfaces are defined in local systems for the user's
          convenience.
        
        * *Beam categories*. xrt discriminates rays by several categories: `good`,
          `out`, `over` and `dead`. This distinction simplifies the adjustment of
          entrance and exit slits. An alarm is triggered if the fraction of dead rays
          exceeds a specified level.
        
        * *Portability*. xrt runs on Windows and Unix-like platforms, wherever you can
          run python.
        
        * *Examples*. xrt comes with many examples; see the gallery.
        
        Dependencies
        ------------
        The histogramming is done by means of `numpy`; `matplotlib` is used
        for plotting. If you use calculations on GPU (so far, only for calculating
        undulators), you need AMD/NVIDIA drivers, Intel SDK for OpenCL, a CPU only
        OpenCL runtime, pytools and pyopencl.
        
        Python 3
        --------
        The code can be fully automatically converted to Python 3 with ``2to3`` at its
        default options.
Platform: OS Independent
Classifier: Development Status :: 5 - Production/Stable
Classifier: Intended Audience :: Science/Research
Classifier: Natural Language :: English
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 3
Classifier: License :: OSI Approved :: MIT License
Classifier: Topic :: Scientific/Engineering :: Physics
Classifier: Topic :: Scientific/Engineering :: Visualization
