www.gusucode.com > map 案例源码 matlab代码程序 > map/DefineGeolocatedDataGridExample.m
%% Define Geolocated Data Grid % To define a geolocated data grid, you must define three variables: a % matrix of indices or values assocaited with th mapped region, a matrix % giving cell-by-cell latitude coordinates, and a matrix giving % cell-by-cell longitude coordinates. %% % Load a MAT-file containing an irregularly shaped geolocated data grid % called mapmtx. load mapmtx %% % View the variables created from this MAT-file. Two geolocated data grids % are in this data set, each requiring three variables. The values % contained in |map1| correspond to the latitude and longitude coordinates, % respectively, in |lt1| and |lg1|. Notice that all three matrices are the % same size. Similarly, |map2|, |lt2|, and |lg2| together form a second % geolocated data grid. These data sets were extracted from the |topo| data % grid shown in previous examples. Neither of these maps is regular, % because their columns do not run north to south. whos %% % Display the grids one after another to see their geography. close all axesm mercator gridm on framem on h1=surfm(lt1,lg1,map1); h2=surfm(lt2,lg2,map2); %% % Showing coastlines will help to orient you to these skewed grids. Notice % that neither |topo| matrix is a regular rectangle. One % looks like a diamond geographically, the other like a trapezoid. he % trapezoid is displayed in two pieces because it crosses the edge of the % map. These shapes can be thought of as the geographic organization of the % data, just as rectangles are for regular data grids. But, just as for % regular data grids, this organizational logic does not mean that displays % of these maps are necessarily a specific shape. load coastlines plotm(coastlat,coastlon,'r') %% % Now change the view to a polyconic projection with an origin at 0°N, % 90°E. As the polyconic projection is limited to a 150° range in % longitude, those portions of the maps outside this region are % automatically trimmed. setm(gca,'MapProjection','polycon','Origin',[0 90 0])