field(1rheolef)

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

✨ field — bestie edition ✨

okay so this is field from rheolef-7.2, section 1rheolef of the manual, and it's literally the glow-up tool for your finite element data. sit down, grab a strawberry 🍓, we're plotting fields today.

🌸 NAME 🌸

field — plot a field (rheolef-7.2) 💅

🎀 SYNOPSIS 🎀

field [options] file[.field[.gz]]

🦋 DESCRIPTION 🦋

It reads a finite element field from a file and outputs it. That's the whole vibe. Read, output, slay. ✨

🍓 EXAMPLE 🍓

field square.field
field square.field -bw
field box.field

like... three commands, three moods. iconic.

🌈 INPUT FILE SPECIFICATION 🌈

  • filename — this is the name of the file that has your input field in it. that's it, that's the job.
  • - — read the field from standard input instead of from a file. very main character, very mysterious, nobody knows where it came from 💀
  • -name — when your field comes in from standard input, the file base name is lowkey unknowable, so it defaults to 'output'. this option lets you change that default. super useful when you're dealing with output formats (graphic stuff, format conversion) that create auxiliary files based on this name. 🎀
  • -Idir and -I dir — add dir to the Rheolef file search path. this is the one you want when your mesh .geo and your .field files are living in different directories (long distance relationship 😭). this mechanism initializes a search path given by the environment variable RHEOPATH. and if RHEOPATH isn't set? default value is the current directory. periodt.
  • -mark string, -catch string, -catchmark string — jump across the file to the specified string. label start at the beginning of a line, preceded by a # mark (see catchmark(3)). iykyk.

💖 OUTPUT FILE FORMAT OPTIONS 💖

  • -field, -text — output the field on the standard output stream in Rheolef ascii (field or geo) text file format. plain, honest, reliable.
  • -gmsh — output field on standard output stream in .gmsh file format.
  • -gmsh-pos — output field on standard output stream in .gmsh-pos file format, suitable for mesh adaptation purpose. she adapts. 💅
  • -bamg-bb — output field on standard output stream in bamg-bb text file format, suitable for mesh adaptation purpose.
  • -image-format string — for image or video capture. the supported argument are .jpg, .png, .tif and .bmp. this option should be combined with the paraview render. the output file is basename.png where basename is the name of the mesh, or can be set with the -name option. 📸
  • -resolution int int — for the resolution of an image or a video capture. the argument is a couple of sizes, separated by a white space. this option can be used together with the -image-format for any of the bitmap image formats. this option requires the paraview render.

🔍 GETTING INFORMATION 🔍

  • -min, -max — print the min (resp. max) value of the scalar field and then exit. no small talk, just facts.
  • -get-geo — print the name of the mesh associated to the field and exit.

👑 RENDER OPTIONS 👑

  • -gnuplot — use the gnuplot tool. this is the default in one dimension. 1D girlies rise up ✨
  • -paraview — use the paraview tool. this is the default for two- and tri-dimensional geometries.

🎨 RENDERING OPTIONS 🎨

  • -color, -gray, -black-and-white, -bw — use (color / gray scale / black and white) rendering. color rendering is the default. 🌈
  • -[no]showlabel — show or hide title, color bar and various annotations. default is to show labels.
  • -label string — set the label to show for the represented value. this supersedes the default value.
  • -[no]elevation — for two dimensional field, represent values as elevation in the third dimension. the default is no elevation.
  • -scale float — applies a multiplicative factor to the field. this is useful e.g. in conjunction with the elevation option. the default value is 1.
  • -[no]stereo — rendering mode suitable for red-blue anaglyph 3D stereoscopic glasses. this option is only available with paraview. put the glasses on bestie 🕶️✨
  • -[no]fill — isoline intervals are filled with color. this is the default. when -nofill, draw isolines by using lines.
  • -[no]volume — for 3D data, render values using a colored translucid volume. this option requires the paraview code.
  • -[no]cut — cut by a specified plane. the cutting plane is specified by its origin point and normal vector. this option requires the paraview code. 🔪 (affectionately)
  • -origin float [float [float]] — set the origin of the cutting plane. default is (0.5, 0.5, 0.5).
  • -normal float [float [float]] — set the normal of the cutting plane. default is (1, 0, 0).
  • -isovalue [float] and -iso [float] — draw 2d isoline or 3d isosurface. when the optional float is not provided, a median value is used. this option requires the paraview code.
  • -noisovalue — do not draw isosurface. this is the default.
  • -n-iso int — for 2D visualizations, the isovalue table contains regularly spaced values from fmin to fmax, the bounds of the field.

@addindex vorticity @addindex stream function

  • -n-iso-negative int — the isovalue table is split into negatives and positives values. assume there is n_iso=15 isolines: if 4 is requested by this option, then, there will be 4 negatives isolines, regularly spaced from fmin to 0 and 11=15-4 positive isolines, regularly spaced from 0 to fmax. this option is useful when plotting e.g. vorticity or stream functions, where the sign of the field is representative. math but make it aesthetic 💅

@addindex projection @addindex approximation P1

  • -proj approx and -proj — convert all selected fields to approximation approx by using a L2 projection. when argument is omitted, P1 approximation is assumed.
  • -lumped-proj — force P1 approximation for L2 projection and use a lumped mass matrix for it.
  • -round [float] — round the input up to the specified precision. this option, combined with -field, leads to a round filter. useful for non-regression test purpose, in order to compare numerical results between files with a limited precision, since the full double precision is machine-dependent. she's precise but not that precise 🎀
  • -subdivide int — when using a high order geometry, the number of points per edge used to draw a curved element. default value is the mesh order.
  • -deformation, -velocity — render vector-valued fields as deformed mesh using paraview or gnuplot. this is the default vector field representation. when velocity, render vector-valued fields as arrows using paraview instead. 🏹

🧚 COMPONENT EXTRACTION AND DOMAIN REDUCTION 🧚

  • -comp int and -comp string — extract the i-th component of a vector-valued field. for a tensor-valued field, indexing components as 00, 01, 11... is supported.
  • -domain name — reduce the visualization to the specified domain name. shrink the scope, keep the drama.

💜 OTHERS OPTIONS 💜

  • -[no]verbose — print messages related to graphic files created and command system calls (this is the default).
  • -[no]clean — clear temporary graphic files (this is the default).
  • -[no]execute — execute graphic command (this is the default). the -noexecute variant is useful in conjunction with the -verbose and -noclean options in order to modify some render options by hand. DIY era 🛠️

⭐ FIELD FILE FORMAT ⭐

It contains a header and a list values at degrees of freedom. the header contains the field keyword followed by a line containing a format version number (presently 1), the number of degrees of freedom (i.e. the number of values listed), the mesh file name without the .geo extension, the approximation (e.g. P1, P2, etc), and finally the list of values:

A sample field file write

field
1 4
square
P1
0.0
1.0
2.0
3.0

See also geo(1) for the .geo mesh file format.

🔥 EXAMPLES 🔥

The following command send to vtk the cuted 2d plane of the 3d field:

field cube.field -cut -normal 0 1 0 -origin 0.5 0.5 0.5 -vtk

Next, let us generate the cuted 2d field and its associated mesh:

field cube.field -cut -normal 0 1 0 -origin 0.5 0.5 0.5 -text > cube-cut.field

For drawing the isosurface:

field cube.field -isovalue 0.5

Finally, let us generate the isosurface as a 3d surface mesh in the .geo file format:

field cube.field -isovalue 0.5 -text > isosurf.geo

This file is then suitable for others treatments. handing it off like a baton 🫶

🛠️ IMPLEMENTATION 🛠️

This documentation has been generated from file main/bin/field.cc

💖 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 real talk for one sec: there is NO WARRANTY, to the extent permitted by law. not a vibe, just the law. 🫡

rheolef — Version 7.2, and that's the whole field(1rheolef) page bestie. go plot something gorgeous, you ate 💅✨🦋

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