mkgeo_ugrid(1rheolef)

📦
version 7.2 · 4 versions
, in debian trixie, ubuntu noble, ubuntu questing

💖 mkgeo_ugrid — bestie edition 💖

okay so this is mkgeo_ugrid, a lil tool from the rheolef-7.2 era (yes, the manual page is mkgeo_ugrid(1rheolef)), and it makes you an unstructured mesh of a parallelepiped. no cap. it's giving "I don't wanna hand-write a gmsh input file" energy and honestly? iconic.

✨ SYNOPSIS ✨

mkgeo_ugrid [options] n

🌸 EXAMPLE 🌸

mkgeo_ugrid -t 10 > square-10.geo
geo square-10.geo

so the command above literally builds a triangle-based, 2d unstructured mesh of the unit square. slay.

🦋 DESCRIPTION 🦋

this command is the vibe when you're testing programs on simple geometries. how you call it is basically the same as mkgeo_grid(1). under the hood it calls gmsh as the unstructured mesh generator — which means you get to skip the whole "prepare an input file for a mesh generator" side quest. we love a shortcut. 🫶

the optional n argument is an integer that says how many subdivisions you want in each direction. and if you just don't say anything? default is n=10. cute. the mesh file goes to standard output, so redirect it or pipe it, bestie.

this command supports literally every possible element type: edges, triangles, rectangles, tetrahedra, prisms and hexahedra. and yeah, it also does mixed 2D with triangles and quadrangles:

mkgeo_ugrid -tq 10 | geo -

and mixed 3D with tetraedra, prisms and/or hexahedra:

mkgeo_ugrid -TP  10 | geo -paraview -
mkgeo_ugrid -PH  10 | geo -paraview -
mkgeo_ugrid -TPH 10 | geo -paraview -

periodt. 💅

🔥 ELEMENT TYPE OPTION 🔥

pick your fighter:

  • -e — 1d mesh using edges.
  • -t — 2d mesh using triangles.
  • -q — 2d mesh using quadrangles (rectangles).
  • -T — 3d mesh using tetrahedra.
  • -P — 3d mesh using prisms.
  • -H — 3d mesh using hexahedra.
  • -tq — 2d mesh using both triangles and quadrangles.
  • -TP, -PH, -TPH — 3d mixed mesh combining tetrahedra, prisms and/or hexahedra.

🎀 THE GEOMETRY 🎀

  • -a float
  • -b float
  • -c float
  • -d float
  • -f float
  • -g float

the geometry can be literally any [a,b] segment, [a,b]x[c,d] rectangle, or [a,b]x[c,d]x[f,g] parallelepiped. by default a=c=f=0 and b=d=g=1, so yeah — the unit boxes are what you get unless you say otherwise. 💜

🌈 BOUNDARY DOMAINS 🌈

  • -[no]sides — the boundary sides are represented by domains: left, right, top, bottom, front and back.
  • -[no]boundary — this option defines a domain named boundary that groups all the sides together. one big happy family fr fr.

🧚 REGIONS 🧚

  • -[no]region — the whole domain gets split into two subdomains: east and west. also, the separating domain is named interface in the mesh. this option is used for testing computations with subdomains (e.g. transmission problem; see usersguide). main character energy for real.

⭐ CORNERS ⭐

  • -[no]corner — the corners (four in 2D and eight in 3D) are defined as OD-domains. this could be useful for some special boundary conditions. tiny but mighty. ✨

💫 COORDINATE SYSTEM OPTIONS 💫

  • -cartesian
  • -rz
  • -zr

specifies the coordinate system. the default is cartesian, while -rz and -zr denote some axisymmetric coordinate systems. reminder bestie: most of Rheolef codes are coordinate-system independent, and the coordinate system is specified in the geometry file .geo. iykyk.

👑 THE MESH ORDER 👑

this option is related to curved boundaries. since boundaries here are flat, this option has no practical effect and is provided for test purpose only. so don't come for me, it's just vibes.

  • -order int — the polynomial approximation mesh order, as defined by gmsh. this option enables a possible curved boundary, when applying a suitable nonlinear transformation to the mesh. default is order=1.

🛠️ IMPLEMENTATION 🛠️

this documentation has been generated from file main/sbin/mkgeo_ugrid.sh. that's the source of truth, babes.

💜 AUTHOR 💜

Pierre Saramito <Pierre.Saramito@imag.fr>

Copyright (C) 2000-2018 Pierre Saramito <Pierre.Saramito@imag.fr> GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

ok and that's the whole page, bestie 💖 go mesh something cute. sending you the biggest rheolef Version 7.2 energy from the mkgeo_ugrid(1rheolef) group chat — mwah, bye! 🎀🦋✨
📦 where this page comes from