GFem language documentation -- 3.9.6 Precise

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### 3.9.6 Precise

This keyword warns Gfem that precise quadrature formula must be used. Hence array-functions are discretized as piecewise linear discontinuous functions on the triangulation. Then all integrals are computed with 3 inner Gauss points slightly inside each triangle.

This option consumes more memory (3nt instead of ns per functions, i.e. 9 times more approximately, but still it is nothing compared with the memory that a matrix of the linear system of a PDE requires) because each array-function is stored by 3 values on each triangles.

It is a good idea to use it in conjunction with `convect` and/or discontinuous nonlinear terms.