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precession: Synthesize precession image

"precession" can calculate precession pictures from a series of ".kcd" images. The resulting synthetic image can be manipulated using ndisp.

Usage

precession [options] [plane definition]... [.x or .rmat file] <imagefilenames>

Plane definitions should be in the form of "0kl", "h0l" or "hk0", where any floating point number can be given in the place of the 0 (i.e. "-8kl" or "h7l" or "0.5kl"). The direction indicated by the first letter will be horizontal in the image. Any number of plane definitions can be given on the command line (more than one precession image can be made in one run), but more images take more memory.

One ".rmat" or ".x" file can be specified on the command line to retrieve the unit cell orientation. If none is specified, a recent one will be chosen from the current directory.

Different image file types are recognized from their names. If no images are given, image files starting with the letters s and t are used. If the rotation angle per frame of the images is large (larger than e.g. 1.0 degrees), the "impression" of the precession image may suffer.

The program accepts all options for controlling the way the unit cell is treated, plus:

thick=thickness: Set the (half) thickness of the plane to "thickness". Default=0.1. If thickness is e.g. 0.2, a 0kl plane will show a projection of the slice -0.2,k,l through +0.2,k,l.
imsize=pixels: Set the square size of the synthetic image in pixels. Default imsize=550.
resolution=res: Set the resolution at the edge of the synthetic 0th-order image. The default is determined by the diffracting power of the crystal, or, if that has not been determined, 0.77 Angstrom (full copper sphere). The scale is set independent of which layer is pictured, such that comparisons can be made between images.

Bugs

Making a precession image can take very long (3-5 seconds per KCD image).

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Next: peakat: Show single peak properties