Mercurial > repos > public > sbplib_julia
diff docs/src/manifolds_charts_atlases.md @ 2003:524a52f190d7 feature/sbp_operators/laplace_curvilinear
Merge feature/grids/geometry_functions
author | Jonatan Werpers <jonatan@werpers.com> |
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date | Tue, 29 Apr 2025 09:03:05 +0200 |
parents | d89f7a1a6f37 |
children |
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--- a/docs/src/manifolds_charts_atlases.md Tue Feb 11 09:03:04 2025 +0100 +++ b/docs/src/manifolds_charts_atlases.md Tue Apr 29 09:03:05 2025 +0200 @@ -1,18 +1,25 @@ # Manifolds, Charts, and Atlases To construct grids on more complicated geometries we use manifolds described -by one or more charts. The charts describe a mapping from some parameter space -to the geometry that we are interested in. If there are more than one chart -for a given geometry this collection of charts and their connection is -described by and atlas. +by one or more charts. The charts describe a mapping from a logical parameter +space to the geometry that we are interested in. If there are more than one +chart for a given geometry this collection of charts and how they are +connected is described by an atlas. + +We consider a mapping from the logical coordidinates ``\xi \in \Xi`` to the +physical coordinates ``x \in \Omega``. A `Chart` describes the mapping by a +`ParameterSpace` respresenting ``\Xi`` and some mapping object that takes +arguments ``\xi \in \Xi`` and returns coordinates ``x\in\Omega``. The mapping +object can either be a function or some other callable object. For the construction of differential and difference operators on a manifold -with a chart the library needs to know the Jacobian of the mapping as a -function of coordinates in the logical parameter space. Internally, -Diffinitive.jl uses a local Jacobian function, `Grids.jacobian(f, ξ)`. For -geometry objects provided by the library this function should have fast and -efficient implementations. If you are creating your own mapping functions you -can implement `Grids.jacobian` for your function or type, for example +with a chart the library needs to know the Jacobian, +``\frac{\partial x}{\partial \xi}``, of the mapping as a function of +coordinates in the logical parameter space. Internally, Diffinitive.jl uses a +local Jacobian function, `Grids.jacobian(f, ξ)`. For geometry objects provided +by the library this function should have fast and efficient implementations. +If you are creating your own mapping functions you must implement +`Grids.jacobian` for your function or type, for example ```julia f(x) = 2x @@ -32,5 +39,3 @@ using ForwardDiff Grids.jacobian(f,x) = ForwardDiff.jacobian(f,x) ``` - -<!-- What more needs to be said here? --/>