MATLA的转mike

%MZMESHANALYSE Analyse and improve mesh. % % mzMeshAnalyse analyses a mesh and highlights elements which gives the % mesh a "bad" quality. The user can zoom in on the worse element or % toggle between the 20 worse elements in the mesh. And the user can edit % and modify the mesh in order to improve on the quality. % % Usage: % mzMeshAnalyse() % mzMeshAnalyse(meshfilename) % mzMeshAnalyse(meshfilename,s) % % Inputs: % meshfilename : filename of mesh file. Leave out or use [] to open % a file selection dialog % s : Initial constant surface elevation, % optional, default s=0 % % The quality of the mesh is measured in three different ways: % 1) Simulation timestep (dt) based on a CFL condition (sqrt(g*h)). % Using this measure, the user can decrease simulation runtime, often % by only editing a few number of elements, significant amount of % time is saved. % 2) Smallest angle of elements. Elements with small angles give more % inaccurate results and should be avoided. % 3) Smallest area of elements. Small elements close to larger elements % can give more inaccurate results % % Note that the plot title contains status information of the current % edit mode, and current quality measure values. 3 values of the current % quality measure are presented on the form % % smallest [1 5 20]th dt : [3.35 3.74 4.74]s (original 2.37s) % % By pressing 'p' the values in percentage are shown on the form % % smallest [1 5 20]th dt: [70.7 63.2 49.9]% of original 2.37s % % This means that the original minimum dt before editing the mesh was % 2.37, and the current worse, 5th worse and 20th worse dt is 3.35, 3.74, % and 4.74 respectively, which is 70.7, 63.2 or 49.9 percent of the % original minimum time step. If correcting the 4 (or 19) worse elements % of the current mesh, the minimum dt increases from 3.35 to 3.74 (or % 4.74). When the difference between the three values in the vector is % small, further modifications will only have a minor effect on % simulation time. % % The dt calculated here relate closely to the dt that is used in the % MikeZero engines. This dt is only static and does not add effect of % current speed on the dt limitations. % % You can zoom in to the "bad" elements and manually edit the mesh. % 1) Collapse a face: Select a face, and the two end-nodes of the face % is collapsed to one node at the center of the face. % 2) Collapse an element: Select an element, and the element nodes are % collapsed to one node at the center of the element. % 3) Create a quad from two neighbouring triangles, by deleting the face % in between the two. % 4) Delete a node: Mesh is updated accordingly. % 5) Mode a node % 6) Add a node % Whenever editing the mesh, it is the users responsibility that the mesh % is still valid and is a good quality mesh. With this tool you can % modify the mesh such that it is no longer valid for simulations, or % will give inaccurate results. % % In the plot there are 3 different indicators on bad elements, when % the measure is dt. % 1) A mark at one node indicates that the position/existence of this % node limits the timestep. The node is a candidate for being % moved/deleted. % 2) A mark on a face (and its end-nodes) indicate that the % length/existence of this face limits the timestep. The face is a % candidate for a collapse. % 3) A mark at the center of the element indicates that no special % features where found that limits the timestep, apart from the size % of the element and its total water depth. You may try to collapse % the element. % % Several shortcuts can be used (when focus is on the mesh figure) % % Keys controlling zoom % 'g' : Global view % 'v' : Zoom to worse element % 'b' : Zoom toggling between the 20 worse elements % 'i' : Zoom in (not global view) % 'o' : Zoom out (not global view) % % Keys controlling measure % '1' : Use dt as measure % '2' : Use smallest angle as measure % '3' : Use element area as measure % 'p' : Toggle between absolute measure and percentage of original % % Keys controlling edit mode % 'f' : Collapse face % 'e' : Collapse element % 'q' : Create quad from two triangles sharing a face % 'd' : Delete node % 'm' : Move node % 'a' : Add node % 'z' : Undo last action (at most 10 actions can be undone) % 's' : Save mesh using new file name (modXX_originalfilename) % % Other keys % 'h' : Print help text to Matlab console % 'y' : Plot histograms of mesh properties % 'c' : Toggle color/black-white mesh (color is less performant) % % Note: If using the figure toolbar, e.g., for zooming, you need to % unselect the tool on the toolbar before the shortcuts will work again. % % Due to performance issues in the Matlab plotting routines, for larger % meshes, only a fraction of the internal elements are plotted. All % element on the boundary are plotted. Also all "bad" elements and their % neighbours are plotted. % % Based on the concepts and initial analysis code presented in Lambkin, % D.O. (2007) 'Optimising mesh design in MIKE FM'. DHI website and In: % Dix, J.K., Lambkin, D.O. and Cazenave, P.W. (2008) 'Development of a % Regional Sediment Mobility Model for Submerged Archaeological Sites'. % English Heritage ALSF project 5224. % Copyright, DHI, 2007-11-09. Author: JGR