如何检查坐标网格中是否存在坐标对(纬度，经度)? [英] How to check if a coordinate pair (lat,lon) exists in a coordinate grid?

问题描述

我有一种算法，可以在满足某些条件时使用地理坐标来计算形状.该算法将输出纬度列表和经度列表，如下所示.因此lat [0]和lon [0]将代表一个坐标对.我想创建一个纬度和经度图形状的布尔数组，如果算法输出中存在相应的坐标点，则索引将为真.我有netcdf文件中的原始纬度和经度信息，但是如何制作一个可以与算法输出进行比较的2d坐标点数组，然后使用匹配索引来创建此布尔数组?

I have an algorithm that computes shapes using geographic coordinates when certain conditions are satisfied. The algorithm outputs a latitude list and a longitude list like seen below. So lat[0] and lon[0] would represent a coordinate pair. I want to create a boolean array in the shape of a latitude and longitude map where the indices would be true if a corresponding coordinate point exists in the algorithm output. I have the original latitude and longitude information from the netcdf file, but how do I make a 2d array of coordinate points that can be compared against the algorithm output, and then use the matching indices to make this boolean array?

我尝试将纬度和经度合并为一个数组. len(lat)= 81，len(lon)= 480 ，我需要一个(81,480)数组.我认为我必须使用numpy where函数来确定坐标对匹配的位置.

I've tried combining the latitude and longitude into a single array. len(lat) = 81, len(lon) = 480 and I need an array of (81,480). I figure I would have to use an numpy where function to determine where the coordinate pairs match.

lat_alg = [-47.25 -47.25 -47.25 -48.   -48.   -48.   -48.   -48.   -48.   -48.
 -48.   -48.75 -48.75 -48.75 -48.75 -48.75 -48.75 -49.5  -49.5  -49.5
 -49.5  -50.25 -50.25 -50.25]
lon_alg = [225.75 226.5  227.25 226.5  227.25 228.   228.75 229.5  230.25 231.
 231.75 228.   228.75 229.5  230.25 231.   231.75 229.5  230.25 231.
 231.75 230.25 231.   231.75]

我创建的布尔数组是... ar_tracker = np.zeros((len(lat)，len(lon)))

The boolean array I create is ... ar_tracker = np.zeros((len(lat),len(lon)))

我希望输出为1，坐标匹配.

and I want the output to be 1 where the coordinates match.

推荐答案

为了完全确定该对是否存在，建议您建立一个元组列表，其中每个元组都包含一对(纬度，经度).例如:

In order to be totally sure about if the pair exists, I suggest you build a list of tuples where each tuple contains a pair (lat,lon). For example:

def Mesh(X,Y):
    A=[]
    for x,y in zip(X,Y):
        A.append((x,y))

    return A

Coord=Mesh(lat_alg,lon_alg)

然后，如果您知道网格分辨率，则可以按以下步骤轻松检查对:

Then, if you know your grid resolution, you can easily check a pair as follows:

coord=(-49.5,230.25)

if coord in Coord:
    print('True')
else:
    print('False')

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