fracextract & grainextract

Hi Robert,

fracextract uses similar syntax to dump2vtk. A typical fracextract commandline is:

fracextract -i snapshot -o fractures.vtu -vtk -rot -t 0 251 1000

Sometimes it is useful to get a full listing of the fracture times, locations etc. This is obtained by removing the '-vtk' argument above e.g.

fracextract -i snapshot -o fractures.txt -rot -t 0 251 1000

grainextract is quite different from the other two tools (fracextract and dump2vtk). It works on individual snapshots rather than a range of snapshots. It also has a wide range of output options. Two of the most common usages are the following:

1) add grain mass and grain ID to snapshot VTK files:
A) generate a grains list (identifying which particles belong to each grain/fragment) at timestep number 10000:
grainextract -i snapshot_t=10000_0.txt -list grains.list

B) generate VTK files using dump2vtk, providing the grains list as an argument:
dump2vtk -i snapshot -o snaps_ -rot -t 0 251 1000 -list grains.list

2) generate a list of grain masses (useful for constructing fragment size-distributions) at timestep number 10000:
grainextract -i snapshot_t=10000_0.txt -om grainMass_t=10K.txt

A full listing of the various grainextract options is provided in Tools/ExtractGrains/main.cpp of the source code. From that file:

Options:
   -i FILENAME : input file name
   -oc FILENAME : output nr. or particles per grain
   -list FILENAME : output list of particle id/ grain id pairs
   -om FILENAME : output mass of grains
   -dm FILENAME BASE CUMULATIVE(0/1) : output grain mass distribution
   -dd FILENAME BASE CUMULATIVE(0/1) : output grain diameter distribution
   -ds FILENAME BASE SMIN: "sieve" distribution
   -p PERC: get sieve size (diameter) for x-th mass percentile
   -vtk FILENAME MINMASS : write out grains above a minimal mass as vtk-xml files
   -tag MINTAG : ignore particles with tag<MINTAG
   -tagrange MINTAG MAXTAG : include only particles with MINTAG <= tag <= MAXTAG
   -diff FILENAME_1 FILENAME_2 : difference between to snapshots (req. -rmass or -fvtk)
   -rmass FILENAME : in combination with -diff, write relative size of largest fragment
   -rmf FILENAME COUNT : in combination with -diff, write the sizes of all fragments, return nr. of fragments written
   -minmass MINMASS : with -rmf, writes only fragments of grains with m>MINMASS
   -fvtk FILENAME EXP :
   -fv : write new grain id as fake vector field
   -profile FILENAME YMIN YMAX NBIN write y-profile of equiv. diameter
   -mprofile FILENAME YMIN YMAX NBIN SIZE_LIMIT write y-profile of matrix fraction
   -grid FILENAME XMIN XMAX YMIN YMAX ZMIN ZMAX CELLDIM
   -crossxy POS FILENAME W H FS : cross section in x-y plane, FS: 1 to filter singles, 0 not to filter
   -crossxz POS FILENAME W H FS : cross section in x-z plane
   -crossyz POS FILENAME W H FS : cross section in x-z plane
   -ppm : if cross section, save as PPM
   -abrasion FILENAME : output splitting/abrasion generated area. FILENAME: original (time step 0) data
   -btag TAG : only consider bonds with tag TAG
   -ocp FILENAME : write list of grain id / grain center position

Note that some of these options require the input simulation to have a specific model setup or require grainextract to be executed multiple times with different output options. If you are interested to use some of these options, I suggest you post another question to this thread so the relevant expert can reply. I mostly just use the two use cases described above.

Cheers,

Dion