Pole Figure Data (The Class PoleFigure)

This section describes the class PoleFigure and gives an overview over the functionality MTEX offers to analyze pole figure data.

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Class Description
Import pole figure data
Plot pole figure data
Manipulate pole digure data
Calculate an ODF from pole digure data
Simulate pole figure data
Complete Function list

Class Description

The general workflow to deal with pole figure data in MTEX is as follows.

Import pole figure data

The most comfortable way to import pole figure data into MTEX is to use the import wizard, which can be started by the command

import_wizard

If the data are in a format supported by MTEX the import wizard generates a script which imports the data. More information about the import wizard and a list of supported file formats can be found here. A typical script generated by the import wizard looks a follows.

% specify scrystal and specimen symmetry
cs = crystalSymmetry('-3m',[1.4,1.4,1.5]);

% specify file names
fname = {...
  fullfile(mtexDataPath,'PoleFigure','dubna','Q(10-10)_amp.cnv'),...
  fullfile(mtexDataPath,'PoleFigure','dubna','Q(10-11)(01-11)_amp.cnv'),...
  fullfile(mtexDataPath,'PoleFigure','dubna','Q(11-22)_amp.cnv')};

% specify crystal directions
h = {Miller(1,0,-1,0,cs),[Miller(0,1,-1,1,cs),Miller(1,0,-1,1,cs)],Miller(1,1,-2,2,cs)};

% specify structure coefficients
c = {1,[0.52 ,1.23],1};

% import pole figure data
pf = loadPoleFigure(fname,h,cs,'superposition',c)

% After running the script the variable *pf* is created which contains all
% information about the pole figure data.
 
pf = PoleFigure  
  crystal symmetry : -3m1, X||a*, Y||b, Z||c*
  specimen symmetry: 1
 
  h = (10-10), r = 72 x 19 points
  h = (01-11)(10-11), r = 72 x 19 points
  h = (11-22), r = 72 x 19 points

Plot pole figure data

Pole figures are plotted using the plot command. It plottes a singe colored dot for any data point contained in the pole figure. There are many options to specify the way pole figures are plotted in MTEX. Have a look at the plotting section for more informations.

figure
plot(pf)

Manipulate pole digure data

MTEX offers a large collection of operations to analyze and manipulate pole figure data, e.g.

An exhausive introduction how to modify pole figure data can be found here As an example, if one wants to remove all intensities with polar angle bewtween 74 and 81 degree one can do

pf(pf.r.theta >= 74*degree & pf.r.theta <= 81*degree) = [];
plot(pf)

Calculate an ODF from pole digure data

Calculating an ODF from pole figure data can be done using the command calcODF. A precise decription of the underlying algortihm as well as of the options can be found here

odf = calcODF(pf,'zero_range','silent')
plotPDF(odf,h,'superposition',c,'antipodal')
applying zero range method to (10-10)............ - reduction: 4298 / 19848
applying zero range method to (01-11)(10-11)............ - reduction: 4298 / 19848
applying zero range method to (11-22)............ - reduction: 3338 / 19848
 
odf = ODF  
  crystal symmetry : -3m1, X||a*, Y||b, Z||c*
  specimen symmetry: 1
 
  Radially symmetric portion:
    kernel: de la Vallee Poussin, halfwidth 5°
    center: 3338 orientations, resolution: 5°
    weight: 1
 

Simulate pole figure data

Simulating pole figure data from a given ODF has been proven to be usefull to analyze the stability of the ODF estimation process. There is an example demostrating how to determine the number of pole figures to estimate the ODF up to a given error. The MTEX command to simulate pole figure is calcPoleFigure, e.g.

cs = crystalSymmetry('m-3m')
pf = calcPoleFigure(SantaFe,Miller(1,0,0,cs),regularS2Grid)
plot(pf)
 
cs = crystalSymmetry  
 
  symmetry: m-3m   
  a, b, c : 1, 1, 1
 
 
pf = PoleFigure  
  crystal symmetry : m-3m
  specimen symmetry: 222
 
  h = (100), r = 72 x 37 points

Complete Function list

ImportPoleFigureDataImporting Pole Figure Data
ModifyPoleFigureDataModify Pole Figure Data
PlotPoleFiguresPlotting of Pole Figures
PoleFigure2odfODF Estimation from Pole Figure Data
PoleFigureAnalysisPole Figure Analysis
PoleFigureAnalysisIntroFirst Steps
PoleFigureSimulation_demoSimulating Pole Figure data
ghost_demoGhost Effect Analysis