s4vs.1 (2540B)
1 .\" Copyright (C) 2015-2018, 2021, 2024 |Méso|Star> (contact@meso-star.com) 2 .\" 3 .\" This program is free software: you can redistribute it and/or modify 4 .\" it under the terms of the GNU General Public License as published by 5 .\" the Free Software Foundation, either version 3 of the License, or 6 .\" (at your option) any later version. 7 .\" 8 .\" This program is distributed in the hope that it will be useful, 9 .\" but WITHOUT ANY WARRANTY; without even the implied warranty of 10 .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 .\" GNU General Public License for more details. 12 .\" 13 .\" You should have received a copy of the GNU General Public License 14 .\" along with this program. If not, see <http://www.gnu.org/licenses/>. 15 .Dd October 13, 2024 16 .Dt S4VS 1 17 .Os 18 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" 19 .Sh NAME 20 .Nm s4vs 21 .Nd invariant property of diffuse random walks 22 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" 23 .Sh SYNOPSIS 24 .Nm 25 .Op Fl n Ar realisations_count 26 .Op Fl s Ar scattering_coeff 27 .Op Ar file 28 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" 29 .Sh DESCRIPTION 30 .Nm 31 statically calculates the average length of diffused paths in the volume 32 bounded by the input geometry. 33 The calculated value is an invariant property of diffuse random walks: 34 it is equal to 4V/S, where V is the volume of the geometry and S its 35 surface area. 36 .Pp 37 The input geometry is assumed to be polygonal, in Obj format, with 38 normals pointing to the interior of the volume according to the 39 left-hand convention. 40 If the file is not defined, the input geometry is read from the standard 41 input. 42 .Pp 43 The options are as follows: 44 .Bl -tag -width Ds 45 .It Fl n Ar realisations_count 46 Number of Monte Carlo realisations. 47 Default is 10000. 48 .It Fl s Ar scattering_coeff 49 Scattering coefficient of the medium within the geometry. 50 The default value is 0, i.e. the medium does not diffuse. 51 .El 52 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" 53 .Sh EXAMPLES 54 Estimate the average length of diffusive random walks in 55 .Pa bunny.obj 56 whose internal medium has a scattering coefficient of 10. 57 Use 1,000,000 Monte Carlo realisations: 58 .Bd -literal -offset Ds 59 s4vs -n 1000000 -s 10 bunny.obj 60 .Ed 61 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" 62 .Sh SEE ALSO 63 .Rs 64 .%A Stéphane Blanco 65 .%A Richard Fourner 66 .%T \&An invariant property of diffuse random walks 67 .%J Europhysics Letters 68 .%V 61 69 .%N 2 70 .%D 2003 71 .%U https://doi.org/10.1209/epl/i2003-00208-x 72 .Re