115 lines
3.0 KiB
C
115 lines
3.0 KiB
C
/*---------------------------------------------------------------------------
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C r y s t
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This is a library of crystallographic utility routines for four
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circle diffractometers. It deals with all sorts of rotations and
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stuff. This is based on code originally developed by John Allibon
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at ILL and reimplemented in C using a matrix-library.
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Mark Koennecke, July 2000
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----------------------------------------------------------------------------*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <assert.h>
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#include <math.h>
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#include "matrix/matrix.h"
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#include "cryst.h"
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#define PIR 57.30
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/*-------------------------------------------------------------------------
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chimat, calculate chi rotation matrix. The input angle is in degrees.
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The setting is Busing & Levy.
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--------------------------------------------------------------------------*/
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MATRIX chimat(double dAngle)
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{
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MATRIX res;
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double dChi;
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res = mat_creat(3, 3, ZERO_MATRIX);
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dChi = dAngle / PIR;
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res[0][0] = cos(dChi);
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res[0][2] = sin(dChi);
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res[1][1] = 1.;
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res[2][0] = -res[0][2];
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res[2][2] = res[0][0];
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return res;
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}
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/*-------------------------------------------------------------------------
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phimat, calculate phi rotation matrix. The input angle is in degrees.
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The setting is Busing & Levy.
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--------------------------------------------------------------------------*/
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MATRIX phimat(double dAngle)
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{
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MATRIX res;
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double dPhi;
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res = mat_creat(3, 3, ZERO_MATRIX);
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dPhi = dAngle / PIR;
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res[0][0] = cos(dPhi);
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res[0][1] = sin(dChi);
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res[2][2] = 1.;
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res[1][0] = -res[0][1];
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res[1][1] = res[0][0];
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return res;
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}
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/*-------------------------------------------------------------------------
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psimat, calculate psi rotation matrix. The input angle is in degrees.
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The setting is Busing & Levy.
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--------------------------------------------------------------------------*/
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MATRIX psimat(double dAngle)
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{
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MATRIX res;
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double dPsi;
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res = mat_creat(3, 3, ZERO_MATRIX);
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dPsi = dAngle / PIR;
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res[0][0] = 1.;
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res[1][1] = cos(dPsi);
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res[1][2] = -sin(dPsi);
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res[2][1] = -res[1][2];
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res[2][2] = res[1][1];
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return res;
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}
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/*-------------------------------------------------------------------------
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diffFromAngles calculates the diffraction vector from two theta, omega
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chi and phi. The angled need not be bissecting but it is assumed that
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the diffraction vector is in the equatorial plane.
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--------------------------------------------------------------------------*/
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MATRIX diffFromAngles(double wave, double tth, double om,
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double chi, double phi)
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{
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MATRIX res, rot, dum, z;
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double dTh;
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dTh = (tth / 2.) / PIR;
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res = mat_creat(3, 1, ZERO_MATRIX);
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res[0][0] = (2. * sin(dTh) * cos(dTh)) / wave;
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res[1][0] = (-2. * sin(dTh) * sin(dTh)) / wave;
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/* undo omega rotation */
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rot = phimat(om);
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dum = mat_tran(rot);
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mat_free(rot);
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z = mat_mul(dum, res);
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mat_free(dum);
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mat_free(res);
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/* result is now z */
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}
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