radiusExtractXY: Extract raster data within a window
In jacpete/jpfxns2: Second Interation of JP Functions - Purdue Edition

Description Usage Arguments Details Value Creation notes

Raster package was missing a function to easily extract data within a window. This is accomplished by using a radius instead of a true window. These are wrappers for the windowExtract() function that does the heavy lifting.

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radiusExtractXY(lon, lat, ras, radius = 1)

radiusExtractData(cellID, rasData, radius = 1)

`lon, lat`	Input locations that you are extracting from.
`ras`	raster* object that the data is being pulled from
`radius`	numeric. radius used to define extractWindow
`rasData`	data.frame object that contains the correct headers ('x', 'y', (valcolumns)). Will need to seperate out this function and create a class for it.

radiusExtractXY() extracts data directly from a raster using lat long coordinates.

radiusExtractData() is an optomized version that works better if the raster you are extracting from never changes and you are using it for multiple points. It uses an input data.frame of the raster values that you can create once and then extracts data by cellID.

Returns a data.frame with the raster values extracted at the current radius.

First created on 2019-Mar-6 in the Lab4inR.R and select.window.R scripts in my IBM class folder of the purdueResearch git. They were developed using base code found at http://rfunctions.blogspot.com/2017/08/extracting-data-from-rasters-using.html?view=classic. It uses another function windowExtract() to do the main work.

jacpete/jpfxns2 documentation built on May 10, 2020, 9:15 p.m.