5c30a7ea7b
- Added calculation of UB from 3 reflections to ubcalc - Added calculation of lattice constants from UB to ubcalc - Some fixes in stdscan in order to make the scripted scan work
77 lines
2.7 KiB
C
77 lines
2.7 KiB
C
/**
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* This is a library for calculating UB matrices for four circle diffraction.
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* The algorithm and setting definitions is from:
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* Busing & Levy, Acta Cryst. (1967), 22, 457ff
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*
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* Implemented:
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* - UB from cell cell constants and two reflections.
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* - Brute force index search
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*
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* Mark Koennecke, march 2005
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*/
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#ifndef SICSUBFOUR
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#define SICSUBFOUR
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#include <stdio.h>
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#include "matrix/matrix.h"
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#include "cell.h"
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/**
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* error codes: also see cell.h
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*/
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#define UBNOMEMORY -200
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#define INVALID_LAMBDA -201
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#define NOTRIGHTHANDED -202
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/**
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* a reflection data structure holding the indices h,k,l and
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* the magic four circle angles two_theta, om, chi and phi.
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*/
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typedef struct{
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double h,k,l;
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double s2t,om,chi,phi;
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}reflection;
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/**
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* calculate a UB matrix from cell constants and two reflections
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* @param direct The direct cell constants
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* @param r1 The first reflection.
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* @param r2 The second reflection.
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* @param errCode an error indicator if things go wrong.
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* @return The resulting UB matrix or NULL on errors
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*/
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MATRIX calcUBFromCellAndReflections(lattice direct, reflection r1, reflection r2, int *errCode);
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/**
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* calculate the UB matrix from three reflections. The three reflections must not be
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* coplanar and must reflect a right handed
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* @param r1 The first reflection
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* @param r2 The second reflection
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* @param r3 The third reflection.
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* @param errCode a code indictang errors which happened.
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* @return A UB matrix on success or NULL on errors. Then errcode will indicate
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* the type of teh error.
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*/
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MATRIX calcUBFromThreeReflections(reflection r1, reflection r2, reflection r3,
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double lambda, int *errCode);
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/**
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* a data structure holding an indexing suggestion
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*/
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typedef struct {
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double h, k, l; /* suggested index */
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double t2obs, t2calc, t2diff; /* 2 theta observed and calculated and the difference */
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}refIndex, *prefIndex;
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/**
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* search for possible indexes matching the two theta value given. This is a brute force search
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* @param direct The lattice constants of the crystal
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* @param lambda The wavelength used
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* @param two_theta The two theta value of the reflection
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* @param max_deviation maximum allowed diviation of calculated two thetas from tw-Theta given
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* @param limit Index limit for the search
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* @param index Preallocated array for storing index suggestions. The procedure will
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* sort the entries in this array according to the difference in two theta
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* @param maxIndex The number of entries allowed for index.
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* @return The number of indexes in index or a negative error code when an error
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* occurs.
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*/
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int searchIndex(lattice direct, double lambda, double two_theta, double max_deviation,
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int limit, refIndex index[], int maxIndex);
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#endif
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