readNWISSample: Import NWIS Sample Data for EGRET analysis
Description
Imports data from NWIS web service.
A list of parameter and statistic codes can be found here: https://help.waterdata.usgs.gov/codes-and-parameters
For raw data, use readNWISqw from the dataRetrieval package.
This function will retrieve the raw data, and compress it (summing constituents) if
more than 1 parameter code is supplied. See
section 3.2.4 of the vignette for more details.