/**
 * This is a library for calculating UB matrices for four circle diffraction.
 * The algorithm and setting definitions is from:
 *            Busing & Levy, Acta Cryst. (1967), 22, 457ff 
 *
 * This initial version only supports the calculation of the UB matrix from
 * cell constants and two reflections.
 *
 * Mark Koennecke, march 2005
 */
#ifndef SICSUBFOUR
#define SICSUBFOUR

#include <stdio.h>
#include "matrix/matrix.h"
#include "cell.h"

/**
 * error codes: also see cell.h
 */
#define UBNOMEMORY -200

/**
 * a reflection data structure holding the indices h,k,l and
 * the magic four circle angles two_theta, om, chi and phi.
 */
typedef struct{
  double h,k,l;
  double s2t,om,chi,phi;
}reflection;
/**
 * calculate a UB matrix from cell constants and two reflections
 * @param direct The direct cell constants
 * @param r1 The first reflection.
 * @param r2 The second reflection.
 * @param errCode an error indicator if things go wrong.
 * @return The resulting UB matrix or NULL on errors
 */
MATRIX calcUBFromCellAndReflections(lattice direct, reflection r1, reflection r2, int *errCode);
#endif