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Manuscript Title: Slit height smearing correction in small angle X-ray scattering IV: computation of the correction function for an arbitrary slit transmission function.
Authors: M. Deutsch
Program title: GTSPLINE
Catalogue identifier: AASD_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 18(1979)149
Programming language: Fortran.
Computer: IBM 370/168.
Operating system: OS/VS2.
RAM: 27K words
Word size: 32
Peripherals: disc.
Keywords: Crystallography, X-ray, Scattering, Diffraction, Smearing, Slit, Small-angle.
Classification: 8.

Nature of problem:
The author's previously published program for correcting slit height smeared data measured in small angle X-ray scattering experiments requires the use of a correction function g(t), which is related to the slit transmission function f(t). The present program calculates the required correction function for an arbitrary slit function, given its numerical values.

Solution method:
A piecewise cubic spline function is fitted to the measured values of the slit transmission function. The fit parameters define an analytically calculated transform of the slit function F^, similar to usual Laplace transform. F^ is then Laplace-inverted numerically to give a set of discrete values of the correction function g(ti), i=1,...,n. Finally, another spline function is fitted to these values, yielding a continuous representation of the desired correction function g(t).

Restrictions:
Only 100 measured values of the slit transmission function are allowed in the present version.

Running time:
About 160 s for 75 transmission function values.