spec - Local Sector 7 web page

19.FOURC> prdef czdef cz ’if ($# != 6) {print "Usage: cz h0 k0 l0 h1 k1 l1"exit}Z[0]=$1; Z[1]=$2; Z[2]=$3; Z[3]=$4; Z[4]=$5; Z[5]=$6calcZprintf("Chi = %g Phi = %g\n", A[chi], A[phi])waitmove; get_angles; calcHKL’20.FOURC>Least-Squares Refinement of Lattice Parameter sIn the previous sections, the procedure described for determining the orientationmatrix required a knowledge of the lattice parameters of the crystal and the positionof two reflections. When such information is unknown, the orientation matrix can befit to an unlimited number of observed peak positions using a least-squaresprocedure. 7 Lattice parameters derived from the fitted orientation matrix can then becalculated, although such lattice parameters are not constrained to exhibit any symmetrywhatsoever.In spec’s implementation of least square refinement, three macros are used to createafile that contains the observed peak positions. That file is eventually run as a commandfile, and the least squares analysis is performed.The reflex_beg macro initializes the reflections file:7 J. Matthews and R. L. Walker, Mathematical Methods of Physics, (Benjamin, Menlo Park, 1970), p. 391.180 FOUR-CIRCLE REFERENCE INTERIM WORK-IN-PROGRESS (8/16/01) NOT FOR GENERAL DISTRIBUTION