Launching Analysis

Steps:

(1) Check that you have an appropriate Matlab install. You need to have:

Matlab 2018a (or above);

Parallel Computing Toolbox;

Global Optimisation Toolbox;

(2) Download AstroEBSD, either from the git - or from a zip.

(3) Unzip to a folder on your PC, likely '/Documents/Matlab/'

(4) Load matlab, and browse to the install folder. You will need to run 'start_astroEBSD.m' as this will add the appropriate folders to your path.

(5) Browse to the folder 'decks' and open 'Input_Deck_single.m'. This is a small deck that will let you run analysis of a single pattern. Navigate to line 7 and change: 'Astro_FP= 'C:\Users\bbrit\Documents\MATLAB\AstroEBSD'; %please change this to your astro file path (HINT - you can type 'cd' in the command window to find your current path)

(6) Run 'Input_Deck_single.m'. A new window will pop up - "Pattern Analysis Settings" - this provides you a chance to see how each of the steps are working in processing your pattern. Click the 'index' button to index your first pattern. You will see that the pattern is indexed with almost 1 degree of misorientation, but that the overlay of bands is good. This is because the pattern centre needs refining. Click 'Search PC' and a genetic algorithm will run which enables the pattern centre to be optimised. This will take a few moments (you can see progress in your command window). Once the new pattern centre is searched and found (closer to [0.525, 0.316, 0.635]) the pattern will index with a lower MAE.

(7) When you are happy with this indexing, you can close the window (click 'close'). And the code will progress. A new figure with your index pattern will be presented and the Workspace will be updated with new variables. A saved 'mat' file of this indexing will be stored in the 'AstroEBSD\outputs' folder too (with timestamp).

The structure EBSP_single is interesting to explore, it has the following fields: PatternIn = input pattern. ebsp_cor = corrected pattern. PatternInfo.size = pixel sizes of the pattern. Peak_Centre = Radon locations of the localised peaks (rho, theta). Peak_Set_All = All the peak information, with column data. R_EBSD = radon transform of the EBSP. R_Edge = edge transform (used for peak localisation). R_rho = rho values. R_theta = theta values. nhat_gnom = nhat vectors in the gnomonic frame rotdata = a structure with the indexed rotation data, includes the orientation matrix in the detector, sample, the Euler angles, the MAE (in radians) and the max number of bands. PatternGeometry is a structure with significant information about the pattern settings (i.e. the Gnomonic frame). Phase has the phase name used for indexing (found in AstroEBSD/phases). PC_err = unknown variable.

Congratulations - you have indexed your first pattern!

Next you may want to move onto map indexing or folder indexing.