GrillasForma de armar una grilla sin utilizar la interface Mohid Gis. NUMBER_OF_SEGMENTS NODES representar) RESOLUTION COORD_TIP: 1 2 3 4 5 6 7 -> -> -> -> -> -> -> : 3 Cantidad de segmentos a partir la grilla : 0.(origen) 25000 75000 150000 (cantidad de unidades a : 1000 300 300 1000 (tamaño de las celdas) Geographic UTM Military Portugal Simple Geography Grid Coordinates Circular NLRD which indicated the type of coordinates used. Note that these keywords are case sensitive. I write the keywords and blocks the grid file must contain: ILB_IUB Minimum I and Maximum I Values. The first value is always zero in both directions. 1) and 3) can be created with MohidGIS. which indicate the origin of the lower left corner of the grid. This information is stored in blocks. You can make 3 kinds od grids: 1) Regular Constant spacing. LONGITUDE Longitude of the lower left corner of the bathymetry. JLB_JUB Minimum I and Maximum I Values. You can find more details. Go to Items. GRID_ANGLE Counter-clock mesh rotation relative to the north.. Although it is a little bit outdated. These two integer variables define the number of points along the X-axis of the grid item. ZONE Zone of the UTM system where the bathymetry is located. and Curvilinear Grids). LATITUDE Latitude of the lower left corner of the bathymetry. . The values are read from left to right corner in the XX axis and from bottom to top in the YY axis. 3) Curvilinear. Still. Each value must be stored in a single line. the part on Grids is still actualized..New.. This value must be of the kind integer.The grid file can be generated in various ways. The data is stored inside a block defined by the following keywords: <BeginXX> and <EndXX> for the XX axis and <BeginYY> and <EndYY> for the YY axis. on the help file that comes in the Mohid Installation package (it is called MohidHelp.. and select the one you want to create. These two integer variables define the number of points along the Y-axis of the grid item. if the spacing is not constant. see under MohidGIS). COORDTYPE A flag. Please check the MohidGIS forum topics (Digital Terrain Tool. being the following values cumulative. The base point is the origin of the bathymetry. The following integer values are accepted: 1: Geographic coordinates 2: UTM coordinates 3: Portuguese military coordinates 4: Simplified geographic coordinates 5: Metric Coordinates referred to the origin of the grid ORIGIN Two real values. one for each direction. 2) Regular Non-Constant spacing.chm. CONSTANT_SPACING_X Boolean defining if the spacing in the XX axis is constant CONSTANT_SPACING_Y Boolean defining if the spacing in the YY axis is constant DX Constant spacing distance in XX axis DY Constant spacing distance in YY axis The grid spacing section contains information about the grid spacing in the XX and YY axis. The easiest is doing it with Mohid GIS. 000000 FILL_VALUE : -99.dat COMENT1 COMENT2 : File generated by : Mohid Digital Terrain Creator ILB_IUB : 1 45 JLB_JUB : 1 5 COORD_TIP : 5 ORIGIN : -69.00000 <BeginXX> 0.0000000E+00 3.000000 9.0000000E+00 LATITUDE : 42.76209 GRID_ANGLE : 0.30000 -47. Formato del archivo de datos de la batimetría interpolada a la grilla. la escritura del archivo ascii correspondiente se hace siguiendo las flechas dibujadas en la figura anterior.000000 6. nombre.000000 .Grillas Simples Para las grillas simple con o sin celdas de tamaño variable.00000 LONGITUDE : -8. HOW TO USE GRIDGEN? 1) Add a Polygon to your project You need to add to your project the polygon that will be the boundary of your meshing domain .400000 1.200000 <EndYY> <BeginGridData2D> 1.0000 celda: 1 1. Thank you for your interest.156251 celda: 2 0. In order to have it you must download the latest version of MOHID (version 4.200000 1.000000 celda: 1 1.950001 celda: 2 1.5000000 celda: 1 -999.000000 2. a grid generator that produces nice structured curvilinear meshes.1) and install it. The program can be downloaded in the MOHID download area.600000 1. INSTALL AND DOWNLOAD The grid generator comes with MOHID GIS.250000 celda: 1 0.00000 <EndXX> <BeginYY> 0.8000000 1.4000000 0.800000 2.000000 1.9374937 celda: 2 <EndGridData2D> 1 2 3 4 5 1 2 3 4 Armado de Grillas Curvilineas Indeed we have just finished implementing GRIDGEN.000000 celda: 1 2.12.2000000 0.499993 celda: 2 1.0000000E+00 0.6000000 0.00000 15. Otherwise the program gives an error. For that. A 'R' should appear near the vertex . picture: upper domain on the second example). A esos puntos los colocamos 1.) 4)Generate the grid Go to "DataItems->New". 3) Define Corners Next step is to define the corners of the polygon. A second click will turn it into a left turn ('R' turn to 'L').if it doesn't. One left click on a vertex turns it into a right turn. To define corners go to "Action->Polygons->Corners Definition". You always have to mark at least 4 right turn corners and this corresponds to a simple polygon. si queremos que sean R y -1 si L. . check size of font in polygon properties as explained before. choose 'properties' and then check the 'render vertices' checkbox. And so on. For a complex polygon one should decompose the domain in many sub-domains. Check the "Curvilinear Grid" option and OK. Your polygon should have at least 4 right turns and the sum of right turns minus the sum of left turns should always be 4. right-click your polygon in the dataitem list. (Otra manera de definir los corners es ir al archivo ASCII del polígono y agregar una tercera columna con todos ceros excepto en los puntos que queremos sean vértices. Corners are used to pave a domain in simpler sub-domains for meshing.The topology of any meshed sub-domain is a four edges polygon and it is defined with 2 left turns and 2 right turns (cf. A third click will turn the vertex to a non-corner vertex (the letter dissapears). So you need to activate 'render vertices' to manipulate the vertices of the polygon. Verify that the size of the font associated to the polygon is in agreement with the scales you are using (otherwise you might see nothing).2) Render Vertices In order to 'prepare' your polygon for meshing you will need to define corners (this will be explained later). NPPE is the Number of Points Per Edge. Errores Cuando los vertices de la grilla no son los correctos el error que arroja el programa es el que se muestra en la figura a continuación. En el ejemplo que está graficado en esa misma figura se puede ver que el polígono que se utilizará para formar la malla tiene 4 vértices R y uno L. NY and NPPE and then OK. . It is the minimum number of grid vertices you will have between two consecutive vertices of your boundary. The program hasn't been tested a lot for the moment. NX and NY are the number of intervals of your grid in the X and Y direction respectively. so we would appreciate any feedback on it.Choose values for NX. Por lo que la suma nR-mL=4R-L=3 (dónde n=cantidad de vértices con R y m=cantidad de vértices con L) y esta debe ser 4.