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 [Licence| Download | New Version Template] acub_v1_0.gz(5 Kbytes) CORRECTION SUMMARY Manuscript Title: FREINT: an integration routine calculating Fresnel diffraction. Authors: W.J. Gruschel Program title: FREINT Catalogue identifier: ACUB_v1_0Distribution format: gz Journal reference: Comput. Phys. Commun. 16(1979)175 Programming language: Fortran. Computer: HONEYWELL BULL 66/60. Operating system: GCOS. RAM: 15K words Word size: 36 Keywords: Optics, Electron microscopy, Fresnel diffraction, Integral transforms. Classification: 18. Revision history: Type Tit le Reference correction 000ACORRECTION 27/11/78 See below Nature of problem:FREINT evaluates the integral A(x) exp(i q (x'-x)**2) dx [i= (-1)**1/2, x = xi,xf] occurring in optical transfer theory. By application of this integral the wave amplitude A(t+d;x') at a plane z = t+d can be calculated on some premises from the amplitude field A(t;x), e.g. in electron microscopy if an object is imaged in a defocussed mode (catchword : Fresnel diffraction). A(x) is given by a complex vector. Solution method:FREINT performs quadratic interpolation of the function A(x) given by N data points (xk, Ak) (Ak complex) in any double interval (xk, xk+2), if h1 = xk+1-xk equals hu = xk+2-xk+1. If not, linear interpolation is chosen. From the interpolatory coefficients the sub-integral values are calculated according to analytical rules and are added up to the final integral value. Restrictions:The integral transformation will be performed for any complex vector, the dimension N of which is greater than or equal to 2 and is limited at the upper end only by limitations of storage. The parameter q must not equal zero. Running time:The execution times depend on N. On the Honeywell Bull 66/60 a vector of length 37 takes approximately 0.05 s, if the abscissae points are equally spaced. Manuscript Title: Unpublished correction to FREINT: an integration routine calculating Fresnel diffraction. Authors: W.J. Gruschel Program title: 000ACORRECTION 27/11/78 Catalogue identifier: ACUB_v1_0Distribution format: gz Classification: 18.
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