Importing Vectors

Directional data usually arrives as a text file with one direction per line - a table of coordinates, or of the two spherical angles. vector3d.load reads such a file once it is told what the columns hold.

plottingConvention.default('y↑→x');

Reading a File

The example file below has two columns, the polar angle and the azimuth angle, both in degree, under a line of headings.

fname = fullfile(mtexDataPath,'vector3d','vectors.txt');

v = vector3d.load(fname,'ColumnNames',{'polar angle','azimuth angle'})

v = vector3d (y↑→x)
 size: 1000 × 1

The column names are what makes the file readable, and they are what decides how the numbers are interpreted. The recognised names are

Angles are read as degree unless the option 'radians' says otherwise. Columns in a different order, or extra columns that are not wanted, are handled by naming their positions.

v = vector3d.load(fname,'ColumnNames',{'polar angle','azimuth angle'},...
  'columns',[1 2]);

Looking at the Result

A thousand directions are too many to read off a table, so the first thing to do with them is a plot. A scatter plot shows the individual directions,

scatter(v,'upper')

and a contour plot shows where they accumulate.

contourf(v,'upper')

The two views answer different questions: the scatter plot says where a measurement exists, the contour plot says where the data is dense. Turning the list into a proper function on the sphere is the subject of Density Estimation.

Next

Writing directions back to a file is Export. Crystal directions read from a file carry a crystal symmetry as well and are imported as Miller indices.