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Subsets PRISM folders on the disk

Source: R/prism_archive_subset.R
prism_archive_subset.Rd

prism_archive_subset() subsets the PRISM folders stored on disk by type, temporal period, and date. It looks through all of the PRISM data that have been downloaded in the prism archive (prism_get_dl_dir()) and returns the subset based on the specified type, temp_period, and dates.

Usage

prism_archive_subset(
  type,
  temp_period,
  years = NULL,
  mon = NULL,
  minDate = NULL,
  maxDate = NULL,
  dates = NULL,
  resolution = NULL
)

Arguments

type

The type of data you want to subset. Must be "ppt", "tmean", "tmin", "tmax", "tdmean", "vpdmin", or "vpdmax".

temp_period

The temporal period to subset. Must be "annual", "monthly", "daily", "monthly normals", or "annual normals".

years

Valid numeric year, or vector of years.

mon

Valid numeric month, or vector of months.

minDate

Date to start subsetting daily data. Must be specified in a valid iso-8601 (e.g. YYYY-MM-DD) format. May be provided as either a character or base::Date class.

maxDate

Date to end subsetting daily data. Must be specified in a valid iso-8601 (e.g. YYYY-MM-DD) format. May be provided as either a character or base::Date class.

dates

A vector of daily dates to subset. Must be specified in a valid iso-8601 (e.g. YYYY-MM-DD) format. May be provided as either a character or base::Date class.

resolution

The spatial resolution of the data, must be either "4km" or "800m". Should only be specified for temp_period of "normals".

Value

A character vector of the folders that meet the type and temporal period specified. character(0) is returned if no folders are found that meet the specifications.

Details

temp_period must be specified so the function can distinguish between wanting annual data or wanting monthly data for a specified year. For example prism_archive_subset("tmean", "annual", years = 2012) would provide only one folder: the annual average temperature for 2012. However, prism_archive_subset("tmean", "monthly", years = 2012) would provide 12 folders: each monthly tmean folder for 2012.

temp_period, years, and mon can be combined in various different ways to obtain different groupings of data. years, mon, and the daily specifiers (minDate/maxDate or dates) are optional. Not specifying any of those would result in getting all annual, monthly, or daily data.

minDate/maxDate or dates should only be specified for a temp_period of "daily". Additionally, only dates, or minDate and maxDate, should be specified, but all three should not be specified. Nor should the daily arguments be combined with years and/or mon. For example, if daily folders are desired, then specify years and/or mon to get all days for those years and months or specify the specific dates using minDate/maxDate or dates

See also

prism_archive_ls()

Examples

if (FALSE) {
# get all annual tmin
prism_archive_subset("tmin", "annual")
# get only 2000-2015 annual tmin
prism_subset_folder("tmin", "annual", years = 2000-2015)

# get monthly precipitation for 2000-2010
prism_archive_subset("ppt", "monthly", years = 2000-2010)
# get only June-August monthly precip data for 2000-2010
prism_archive_subset("ppt", "monthly", years = 2000-2010, mon = 6:8)

# get all daily tmax for July-August in 2010
prism_archive_subset("tmax", "daily", years = 2010, mon = 7:8)
# same as:
prism_archive_subset(
  "tmax", 
  "daily", 
  minDate = "2010-07-01", 
  maxDate = "2010-08-31"
)

# get the 4km 30-year average precip for January and February
prism_archive_subset("ppt", "monthly normals", mon = 1:2, resolution = "4km")
}