--- title: "FeatureCollection" output: rmarkdown::html_vignette vignette: > %\VignetteIndexEntry{FeatureCollection} %\VignetteEngine{knitr::rmarkdown} %\VignetteEncoding{UTF-8} --- ```{r, include = FALSE} knitr::opts_chunk$set( collapse = TRUE, comment = "#>", eval = FALSE ) ``` `rgeeExtra` serves as a wrapper for the Python package named `eeExtra`. The creation of `eeExtra` was driven by a need to consolidate various third-party GEE Javascript and Python packages and projects found on GitHub in the same programming language and style, avoiding dependencies. `rgeeExtra` ensures a seamless integration of `eeExtra` within the R ecosystem ```{r setup} library(rgeeExtra) library(rgee) ee_Initialize() # Initialize the Google Earth Engine API connection extra_Initialize() # Load the extended functionalities of rgeeExtra ``` ## **Features for `ee$FeatureCollection`** `ee$FeatureCollection` objects represent geographic features which are fundamental to spatial analyses. Enhanced manipulation of these objects in R can significantly streamline workflows. ### **1. Subsetting** The `[[` method enables extraction or modification of specific elements within an `ee$FeatureCollection` by index. This function is essential for segmenting and managing subsets of features in Earth Engine for targeted geographic analysis. ```{r} # Load and select the first two features from 'TIGER/2016/Roads' collection. fc_tiger <- ee$FeatureCollection('TIGER/2016/Roads') fc_tiger_subset <- fc_tiger[[1:2]] # Center and display the selected features on the map. Map$centerObject(fc_tiger_subset) Map$addLayer(fc_tiger_subset) ```
### **2. Names** The `names` function for `ee$FeatureCollection` retrieves the names of properties, providing a clear overview of attributes within Earth Engine's feature collections for effective data management and analysis. ```{r} # Load the 'WRI/GPPD/power_plants' Feature Collection from Earth Engine. fc <- ee$FeatureCollection('WRI/GPPD/power_plants') # List the methods and properties available for the feature collection. methodsProperties <- names(fc) # Output includes methods like "aggregate_array", "filter", "map", and properties like "args", "name". ```