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# Version 4.5: new features

## Release, binaries packages

• Since the version 4.5, the FreeFEM binary packages provides with a compiled PETSc library.

• FreeFEM is now interfaced with ParMmg.

## New meshes and FEM border

After Surface FEM, Line FEM is possible with a new mesh type meshL, P0 P1 P2 P1dc FE, basic FEM, mesh generation. This new development allows to treat a 1d problem, such as a problem described on a 3d curve.

Abstract about Line FEM in FreeFEM.

• new meshL type, refer to the section The type meshL in 3 dimension

• new type of surface mesh: meshL

• the functionalities on the meshL type, it is necessary to load the plugin ”msh3”.

• generator of meshL segment, define multi border and buildmesh function.

• basic transformation are avalaible: movemesh, trunc, extract, checkmesh, change, AddLayers, glue of meshL.

It is possible to build the underlying meshL from a meshS with the function buildBdMesh: ThS=buildBdMesh(ThS) builds the boundary domain associated to the meshS ThS and extract it by the command meshL ThL=ThS. Gamma.

• new finite element space with curve finite element type

• FESpace P0 P1, P2, P1dc Lagrange finite elements and possible to add a custumed finite element with the classical method (like a plugin).

• as in the standard 2d, 3d, surface 3d case, the variational problem associated to surface PDE can be defined by using the keywords

• problem

• varf to access to matrix and RHS vector

• available operators are int1d, on and the operator int0d to define a Neumann boundary condition

• visualisation tools

• plot with plot of ffglut, medit meshes meshL and solutions

• 2d or 3d view, with in 3d the option to visualize the elememt Normals at element (touch ‘T’) and the deformed domain according to it (touch ‘2’).