Meteoinfolab Script Example: Inpolygon

The Inpollygon function is used to determine whether the data with coordinates (x/y) is in one or a set of polygons (Polygon), and the returned result is a value of 1 if the polygon is made, otherwise the value is-1. The following example shows the use of a shape file and the Inpolygon function to generate this 0, 1 data. Need to download the latest Meteoinfo version (1.2.6R1): http://yun.baidu.com/share/link?shareid=669776748&uk=51062435

1, generate a lattice point data (2-dimensional array), you can use the Zeros function:
A = Zeros ((50,80), dtype= ' int ')
The resulting array A is a 2-dimensional array of 50*80 with a value of 0.

2. Generate the coordinates of the lattice data (x/y), the Arange1 function generates a 1-dimensional array, and three parameters are the starting value, the number, and the step size, respectively.

3. Read the shape file and return a layer M_china.

4. Use the Inpolygon function of array A to generate a new array b,b the value of the points within the polygon is 1, the other is-1.

5, change the B-1 to 0.

6. Use the Savegrid method of array B to save array B and its coordinate information in a surfer ASCII grid format file.

7, drawing, this is to test it. The 1 in array B is indicated by a red dot, and 0 is shown with a gray dot.

Script Program:

#Create a 50*80 2D arrayA = Zeros ((50,80), dtype='int')#Create x/y vectorx = Arange1 (60, 80, 1) y= Arange1 (10, 50, 1)#Read shape FileM_china = Shaperead ('d:/temp/map/china.shp')#Inpolygon function, In:1, out:-1b =A.inpolygon (x, y, M_china)#Change-1 to 0B[b==-1] =0#Save to a surfer ASCII grid data filefn ='D:/temp/test/sdata.dat'B.savegrid (x, Y, fn)#Plotaxesm () geoshow (M_china) SS= Makesymbolspec (' Point', {'value'70A'Color':'Lightgray','size': 2,'Edge': False}, {'value': 1,'Color':'Red','size': 2,'Edge': False}) Layer= Scatterm (x, y, B, Symbolspec=ss)

Meteoinfolab Script Example: Inpolygon