centerSpecimen

(method of ODF)

rotatates an odf with specime symmetry into its symmetry axes

centerSpecimen(odf,center) trys to find the normal vectors of orthorhombic symmetry for the x mirror and y mirror plane and calculates an rotation needed to rotate the odf back into these mirror planes. the routine starts with an lookaround grid for a given center (default xvector) to find a starting value for newton iteration.

Syntax

[odf,r,v1,v2] = centerSpecimen(odf,center,'param1',val1,'param2',val2)

Input

odf

ODF

center

look arround center for a suiteable start value (default xvector)

param,val Parameters and values that control centerSpecimen
Parameter Description
'delta'

stepsize for evaluating the gradient

'itermax'

maximum number of newton iterations (default 5)

'SO3Grid'

a SO3Grid the ODF is evaluatete on

'maxpolar'

specifies the opening angle for the initial search grid around input center

'resolution'

specifies the resolution for the initial search grid

'silent'

dont verbose number of initial axes and the newton iteration

'plot'

plot objective function around center as axis distribution

'fourier'

use fourier coefficents as objective function

mples rting with an synthetic odf with orthorhombic symmetry

  CS = crystalSymmetry('cubic')
            SS = specimenSymmetry('orthorhombic')
            h = [Miller(0,0,1),Miller(0,1,1),Miller(1,1,1)];
            r = [ rotation('euler', 90*degree,35*degree,30*degree) ...
            rotation('euler', 90*degree,35*degree,0*degree)]
  sr = SS*r;
            odf = unimodalODF(sr,CS);

define a rotational displacement

  r2 = rotation('euler', 6*degree,4*degree,0*degree)
            odf = rotate(odf,r2);
  plotPDF(odf,h,'antipodal');
now retrive the rotation back
  [odr,r,v1,v2] = centerSpecimen(odf);
            plotPDF(odr,h,'antipodal')

Output

odf

rotated ODF

r

its rotation rotate(odf_out,r) = odf_in

v1,v2

normal vector of the mirrorplans