Sometimes, you might want to compare the orientations of grains between two collections, to make sure that they are the same, for instance.

A typical case when you perform this operation is during training. If you generated a synthetic dataset and indexed this data, you will want to make sure that the grains you indexed actually existed at start.

This operation is performed using the timelessGrainComparison script, which is part of the TIMEleSS tools.

Here is the output of the help command

 
timelessGrainComparison --help
usage: timelessGrainComparison [options] file1 file2

Compare grains between 2 files This is part of the TIMEleSS project
http://timeless.texture.rocks

positional arguments:
  file1                 first grain file, used as a reference (gff or
                        GrainSpotter output file, based on extension)
  file2                 second grain file, matched against the previous file
                        (gff or GrainSpotter output file, based on extension)

optional arguments:
  -h, --help            show this help message and exit
  -c {1,2,3,4,5,6,7}, --crystal_system {1,2,3,4,5,6,7}
                        Crystal system. Can be one of the following 1:
                        Triclinic 2: Monoclinic 3: Orthorhombic 4: Tetragonal
                        5: Trigonal 6: Hexagonal 7: Cubic
  -o OUTPUT_STEM, --output_stem OUTPUT_STEM
                        Stem for output files. Default is comp
  -m MISORIENTATION, --misorientation MISORIENTATION
                        Misorientation below which two grains are considered
                        identical, in degrees. Default is 2.0

As an illustration, will will work with synthetic data on stishovite. The following file, simu_stishovite_10grain2.gff , is the result of a PolyXSim simulation for stishovite. It includes the orientations of 10 stishovite grains, randomly oriented.

The author ran a GrainSpotter indexing and generated a GrainSpotter log file: stishovite_10grain2.log.

We want to make sure that the grains indexed by GrainSpotter are the same than those we had in the simulation. In other words, we want to test that our indexing makes sense.

The grain comparison is run as follow

timelessGrainComparison -c 4 -o test-stish simu_stishovite_10grain2.gff stishovite_10grain2.log

We use a tetragonal symmetry (c is set to 4), output files will start with test-stish, the reference grains are found in simu_stishovite_10grain2.gff and we are checking whether the grains in stishovite_10grain2.log are correct.

timelessGrainComparison can read gff or GrainSpotter log files. What matters is the order in which you provide the files. The first file is the reference, the second file will be checked.