{"id":3426,"date":"2021-10-28T12:29:51","date_gmt":"2021-10-27T23:29:51","guid":{"rendered":"http:\/\/blogs.lincoln.ac.nz\/gis\/?p=3426"},"modified":"2023-05-07T02:49:37","modified_gmt":"2023-05-07T02:49:37","slug":"near-and-deer","status":"publish","type":"post","link":"https:\/\/blogs.lincoln.ac.nz\/gis\/near-and-deer\/","title":{"rendered":"Near and Deer Ones"},"content":{"rendered":"

In this post we look at addressing a spatial problem, coming up with an approach and implementing the solution.\u00a0 (Spoiler alert – it worked, but not as it was supposed to.)\u00a0<\/em><\/p>\n

We often get emails here at GIS Central asking for a bit of assistance with things spatial.\u00a0 One never knows what will come through the Inbox and I’m almost always up for a challenge.\u00a0 Why, just the other day we got this:<\/p>\n

“Hi Crile,<\/span><\/p>\n

I am looking for assistance with ArcGIS and was wondering if you may know a thing or two which could help me.”<\/span><\/p>\n

(Ed. They always start off so nice…)<\/em><\/p>\n

“I have 10 individuals with 50 days\u2019 worth of hourly locations (some data points will be missing.)<\/span><\/p>\n

I want to split the data for each individual into 2 day sliding windows, e.g day 1&2, 2&3, 3&4 \u2026 etc.<\/span><\/p>\n

For each two day window, I want to calculate the distance between each location and the first location recorded in that window.<\/span><\/p>\n

Do you know of possible steps in ArcGIS I might undertake to achieve this?”<\/span><\/p>\n

We always aim to please and on the face of it, this certainly sounded feasible (these individuals are deer, by the way).\u00a0 With the idea of “beginning with the end in mind<\/a>“, I began formulating an approach.\u00a0 At this point I think the main output will be a table (CSV or Excel) with a column of distances away from one point, broken down into these sliding time windows.\u00a0 We’re talking about distances between dear locations so the Near<\/a> tool comes to mind immediately – that’s exactly what it’s designed to do.\u00a0 I’m also anticipating that I\u00a0may have to think about how to structure the data to do this most efficiently.\u00a0 With 10 animals and 50 days worth of data I’m already beginning to wonder if this is a manual job or if I’ll need\/want to automate it somehow (either with ModelBuilder<\/a> or Python<\/a>).<\/p>\n

With a very rough plan in mind, the next thing might be to have a look at the data – so I asked for something to work with and was sent a CSV file of the data:<\/p>\n

\"\"<\/a><\/p>\n

A few things to notice about these data:<\/p>\n