12 Neper 3.2.0
• ‘graingrowth’ or ‘gg’ for grain-growth statistical properties, which correspond to a wider
grain size distribution and higher grain sphericities than in a Voronoi tessellation (it actually
is an alias for ‘diameq:lognormal(1,0.35),sphericity:lognormal(0.145,0.03,1-x)’,
see below); the ‘graingrowth(mean)’ and ‘gg(mean)’ variants can be used to provide an
absolute mean grain size, mean (in which case -n from_morpho must be used, see below);
• ‘centroidal’ for a centroidal tessellation
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(it actually is an alias for ‘centroid:seed’,
see below);
• ‘cube(N)’ / ‘square(N)’ for a regular tessellation into cubic / square cells, where ‘N’ is
the number of cells along a direction, or ‘cube(N1,N2,N3)’ / ‘square(N1,N2)’ for a regular
tessellation into cubic / square cells, where ‘N1’, ‘N2’ and ‘N3’ are the number of cells along
the different directions.
• ‘lamellar(w=w,v=v)’ for a lamellar morphology. Argument ‘w=w’ is mandatory and argu-
ment ‘v=v’ is optional. Argument ‘w=w’ enables to specify the absolute lamella width w. For
specifying several widths, combine them with ‘:’. In the case of a multiscale tessellation, for
specifying cell-by-cell width values, use the syntax ‘file(file_name)’ where file_name is
the name of a multiscale cell file containing the list of widths (see Section B.3 [Multiscale
Cell File], page 68). Argument ‘v=v’ enables to specify the lamella plane normals v. For
randomly-distributed normals taken from a uniform distribution, use ‘random’. For a direc-
tion of the parent crystal, use ‘crysdir(dir_x,dir_y,dir_z)’, where (dir x, dir y, dir z) is
the crystal direction. For specifying cell-by-cell normals, use the syntax ‘file(file_name)’
where file_name is the name of a multiscale cell file containing the list of lamella plane
normals (see Section B.3 [Multiscale Cell File], page 68).
(ii) Custom morphological properties can be defined by providing as argument the cell prop-
erty and its value, combined with the ‘:’ separator. The available properties are:
• ‘size’ for the size (volume in 3D and area in 2D) and ‘diameq’ for the equivalent diameter;
• ‘sphericity’ for the sphericity;
• ‘centroid’ for the centroid;
• ‘centroidtol’ for the centroid with a tolerance — centroids with a tolerance higher than
1000 times the minimum tolerance are disregarded;
• ‘centroidsize’ for combined centroid and size, and ‘centroiddiameq’ for combined cen-
troid and equivalent diameter;
• ‘tesr’ for cells of a raster tessellation.
Sizes, diameqs and sphericities can be defined by statistical distributions or on a per-cell
basis, while centroids can be defined only on a per-cell basis. The statistical distributions can
be: a Dirac distribution, ‘dirac(mean)’, a normal distribution, ‘normal(mean,sig)’, log-
normal distributions, ‘lognormal(mean,sig)’ or ‘lognormal(mean,sig,1-x)’ (which means
the variable is (1 − the cell property)), or a sum of distributions of increasing averages, for
example, ‘0.3*normal(mean1,sig1)+0.7*normal(mean2,sig2)’. If the number of cells is
defined (see option -n), the size or diameq distribution is scaled to get the specified num-
ber of cells; otherwise, i.e. -n is set to ‘from_morpho’, the number of cells is determined
from the size or diameq distribution. An interval of possible values can also be provided
using ‘interval(min,max)’. A unique value can be assigned to all cells using ‘value’, where
‘value’ is the value. Cell-by-cell values can be provided using ‘file(file_name)’, where
‘file_name’ is the name of the file containing the cell values (see Section B.4 [Position File],
page 68, for ‘centroid’; add a tolerance to each position for ‘centroidtol’). For ‘centroid’,
provide ‘seed’ to get a centroidal tessellation. For ‘tesr’, ‘file_name’ is the name of the
raster tessellation file. If -n is set to ‘from_morpho’, the number of cells is set to the number
of cells of the raster tessellation.
To specify several properties, combine them with ‘,’ (centroids and sizes/equivalent diame-
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centroidal is not recommended as it does not correspond to a morphological property per se; size and/or
sphericity properties should be used instead.