makeWaterYear: Make Water Year Column

In MGBT: Multiple Grubbs-Beck Low-Outlier Test

Make Water Year Column

Description

Make water year, year, month, and day columns from the date stamp of a U.S. Geological Survey peak-streamflow data retrieval from the National Water Information System (NWIS) (U.S. Geological Survey, 2019) in an R data.frame into separate columns of the input data.frame. Note that NWIS (through dataRetrieval package) will insert padded zeros for missing month and years with in the peak-streamflow data when the variable type conversion is false (see Examples). This function will changes those zeros in the separated columns to missing.

Usage

makeWaterYear(x, datestr="peak_dt")

Arguments

x	A data.frame having a default column titled peak_dt that is in a character format. No other information in x is consulted or otherwise used. A feature of of the function is that x could also be simply a vector of characters in the basic "YYYY-MM-DD", "YYYY-MM", or "YYYY" structure for the conversions; and
datestr	The column name containing the date on which to parse for creation of new columns. The default is aligned with USGS peak-streamflow data.

Value

The x is returned containing only these columns (if x is is.character) or with the addition of these columns:

year_va	The calendar year extracted from peak_dt;
month_va	The optional month extracted from peak_dt;
day_va	The optional day extracted from peak_dt; and
water_yr	The water year, which is not equal to year_va if month_va is greater than or equal to 10 (October).

Author(s)

W.H. Asquith

References

U.S. Geological Survey, 2019, USGS water data for the Nation: U.S. Geological Survey National Water Information System database, accessed October 11, 2019, at \Sexpr[results=rd]{tools:::Rd_expr_doi("10.5066/F7P55KJN")}.

See Also

splitPeakCodes, plotPeaks

Examples

print(makeWaterYear(c("1888-07-00", "1889", "1889-11", "1891-03-04")))
#        date year_va month_va day_va water_yr
#1 1888-07-00    1888        7     NA     1888
#2       1889    1889       NA     NA     1889
#3    1889-11    1889       11     NA     1890
#4 1891-03-04    1891        3      4     1891

## Not run: 
  # The dataRetrieval package is not required by MGBT algorithms.
  PK <- dataRetrieval::readNWISpeak("08167000", convertType=FALSE)
  PK <- makeWaterYear(PK) # Note: The convertType=FALSE is critical.
  names(PK) # See that the columns are there and see that there are padded
  # zeros for missing days for "1869-07-00" and "1936-09-00" and the
  # day_va column will have NAs in lieu of 0s in these examples
## End(Not run)

MGBT documentation built on Oct. 5, 2026, 9:07 a.m.