Technical notes

Short notes (about 4 pages) on methods and features of NGSolve. Each note lives in docs/technotes/<number>_<name>/<name>.tex together with its figures. The PDF and HTML versions are not stored in the repository, they are built with the documentation (make technotes, needs latexmk for the PDF and pandoc for the HTML page).

2026-01 High-order de Rham sequences on mixed meshes (PDF)

Joachim Schöberl. The spaces H1, HCurl, HDiv and L2 on triangles, quads, tets, prisms and hexes: order convention, the type1 and RT flags, degrees of freedom, and the exact sequences they form.

2026-02 The TDNNS method for elasticity (PDF)

Astrid Pechstein, Michael Neunteufel, Joachim Schöberl. Tangential-displacement normal-normal-stress elements: formulation, hybridization, and the space-creation syntax (CreateStressSpace, CreateMultiplierSpace).

2026-03 Mass conserving mixed stress (MCS) methods (PDF)

Philip Lederer, Xaver Mooslechner, Jay Gopalakrishnan, Christopher Lackner, Joachim Schöberl. Spaces and hybrid formulation of the MCS method for Stokes flow, and the space-creation syntax (CreateStressSpace, CreateMultiplierSpace, CreateDivergenceSpace).

2026-04 Nonlinear HHJ shell with frictional contact (PDF)

Michael Neunteufel, Joachim Schöberl. A falling sheet draped over a moving sphere: nonlinear Hellan-Herrmann-Johnson shell, contact and friction, time stepping.

2026-05 Ordering for saddle point matrices in SparseCholesky (PDF)

Joachim Schöberl. Zero diagonal entries and dense rows (NumberSpace) in the minimum degree ordering: the wait rule, the placement of constraints, the flags late, densefac, lastdofs and waitfrac of Inverse, and the measured fill.

Adding a note

Take the next number <year>-<running number>, create docs/technotes/<number>_<name>/<name>.tex, put figures next to it, write the number into its \date line, and add an entry above that links to <number>_<name>.html and <number>_<name>.pdf.

The HTML page is made from the same source by tex2html.py and pandoc. Check it in a browser, pandoc knows less LaTeX than LaTeX:

  • figures included as PDF need a PNG or SVG of the same name next to them;

  • lines starting with %html are read for the HTML page only, use them to redefine macros pandoc cannot handle (TikZ pictures, \\ in a macro);

  • put braces around macro arguments in formulas (\tilde{\Pp}).