Скачать или смотреть How to Find the Closest Geographical Point Using R

Discover how to effectively find the closest geographical points, such as banks in a particular year, using R's spatial capabilities. Learn simple methods and coding examples that make the process easier.
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This video is based on the question https://stackoverflow.com/q/64322082/ asked by the user 'LouisEcon' ( https://stackoverflow.com/u/13999164/ ) and on the answer https://stackoverflow.com/a/64992775/ provided by the user 'LouisEcon' ( https://stackoverflow.com/u/13999164/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Find the Closest Geographical Point Using R: A Step-by-Step Guide

When working with geographical data in R, you may face questions about finding the closest point within a specified group. For instance, if you have several bank locations across different years and need to determine the nearest bank to a specific branch, the task can become a bit complex. This guide aims to provide a clear solution to this problem.

Understanding the Challenge

You have a dataset that contains various bank locations identified by their year, geometry, name, and location. Your goal is to find out the nearest bank to a specific bank within the same year. In some cases, multiple banks may be located in the same physical location, meaning that the closest distance between them would be zero.

Sample Data Overview

Here's a snapshot of the data structure we are dealing with:

YearGeometryBankLocation1838POINT (759859.6 -728345)Bank of MobileMobile1838POINT (779861.1 -445454.7)Bank of the State of AlabamaTuscaloosa1838POINT (819114.6 -285180.1)Bank of the State of Alabama, branchDecatur1841POINT (819114.6 -285180.1)Bank of the State of Alabama, branchDecatur............The Solution: Finding the Nearest Banks

To tackle the problem, follow these organized steps in R using spatial functions. Here’s a reproducible example of the steps used to find the closest geographical points.

Step 1: Prepare Your Data

Ensure that your dataset is formatted correctly as a spatial dataframe. Using the sf package in R, your data should include geometry data.

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Use Spatial Functions to Find Nearest Points

Utilize the st_nn function, which stands for "spatial nearest neighbor." Here's the code to find the 10 closest points for each year:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Combine Results

Once you have determined the nearest neighbors for each year, you can combine all the datasets into one for analysis:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

By following these structured steps, you can efficiently find the closest geographical points in your dataset. This method provides flexibility to work with various spatial data configurations, making it a valuable tool for any geospatial analysis.

Now you can quickly address questions like, "What is the closest bank to the 'Bank of the State of Alabama, branch' in Decatur for the years 1838, 1841, and 1842?"

With R’s powerful spatial capabilities, handling such queries becomes straightforward!