GetCDLStat {CropScapeR}

Request summary statistics of the CDL data

Description

A function that requests summary statistics of the CDL data for any Area of Interests (AOI) in a given year from the CropScape. This function implements the GetCDLStat services provided by the CropScape https://nassgeodata.gmu.edu/CropScape.

Usage

GetCDLStat(aoi = NULL, year = NULL, type = NULL, crs = NULL, tol_time = 20)

Arguments

aoi

Area of interest. Can be a 5-digit FIPS code of a county, 2-digit FIPS code of a state, four corner points or an sf object that defines a rectangle (or a box) area, multiple coordinates that defines a polygon, or a URL of an compressed ESRI shapefile.

year

Year of data. Should be a 4-digit numeric value.

type

Type of the selected AOI. 'f' for state or county, 'b' for box area, 'ps' for polygon, 's' for ESRI shapefile.

crs

Coordinate system. NULL if use the default coordinate system (i.e., Albers projection); Use '+init=epsg:4326' for longitude/latitude.

tol_time

Number of seconds to wait for a response until giving up. Default is 20 seconds.

Details

The usage of this function is similar to the GetCDLData function. Please see the help page of the GetCDLData function for details. Note that the aoi cannot be a single point here.

Value

The function returns a data frame that reports summary statistics of the CDL data for an AOI in a given year.

Examples

# Example 1. Retrieve data for the Champaign county in Illinois (FIPS = 17109) in 2018.
data <- GetCDLStat(aoi = 17019, year = 2018, type = 'f')
head(data, n = 5) # Show top 5 rows of retrieved data

# Example 2. Retrieve data for a polygon (a triangle) defined by three points in 2018.
data <- GetCDLStat(aoi = c(175207,2219600,175207,2235525,213693,2219600), year = 2018, type = 'ps')
head(data, n = 5)

# Example 3. Retrieve data for a rectangle box defined by three corner points in 2018.
data <- GetCDLStat(aoi = c(130783,2203171,153923,2217961), year = '2018', type = 'b')
head(data, n = 5)