metadata: Create or modify the metadata for a load model.
In McDowellLab/loadflex: Models and Tools for Watershed Flux Estimates

Description Usage Arguments Details Value See Also Examples

metadata creates a new metadata object (see metadata-class) from scratch.

updateMetadata modifies an existing metadata object.

metadata(constituent, flow, load.rate = "", dates, conc.units, flow.units,
  load.units, load.rate.units, station = "", custom = NULL,
  validate = TRUE, consti.name = "", site.name = "", site.id = "",
  lat = NA, lon = NA, basin.area = NA, flow.site.name = site.name,
  flow.site.id = site.id, flow.lat = lat, flow.lon = lon,
  flow.basin.area = basin.area, basin.area.units = "km^2")

updateMetadata(metadata, new.metadata = NA, ..., validate = TRUE)

`constituent`	character. The name of the solute or suspended material whose load is to be modeled. Also the name of the data.frame column describing that solute or material.
`flow`	character. The name of the data.frame column describing flow (discharge)
`load.rate`	character. The name of the data.frame column, if it exists, describing instantaneous load
`dates`	character. The name of the data.frame column describing date and/or time
`conc.units`	character. The units in which concentration is both input and exported.
`flow.units`	character. The units in which flow is both input and exported.
`load.units`	character. The units in which load (flux) is both input and exported.
`load.rate.units`	character. The units in which load (flux) is reported by predict.loadModel().
`station`	deprecated. character. A description of the sampling station or site. It's now recommended to use `site.name` and/or `site.id` instead.
`custom`	ANY. Empty by default, but may be modified to store any additional data the user wants to track.
`validate`	logical. If TRUE, validObject() must pass for the object to return.
`consti.name`	character. Consituent long name, for use in plots and reports
`site.name`	character. A description of the station or site where the concentration of the constituent was measured. This argument or `site.id` is a better place for a site identifier than the `station` argument, which is deprecated.
`site.id`	character Station ID for the site where the concentration of the constituent was measured.
`lat`	numeric Station latitude where concentration (and possibly also discharge) was measured.
`lon`	numeric Station longitude where concentration (and possibly also discharge) was measured.
`basin.area`	numeric Area of the drainage basin contributing water to the site where concentrations were measured.
`flow.site.name`	character Long name of the station where flow was monitored, if different from where concentration was monitored (as in `site.name`).
`flow.site.id`	character Station ID of the station where flow was monitored, if different from where concentration was monitored (as in `site.id`).
`flow.lat`	numeric Latitude of the station where flow was monitored, if different from where concentration was monitored (as in `site.lat`).
`flow.lon`	numeric Longitude of the station where flow was monitored, if different from where concentration was monitored (as in `site.lon`).
`flow.basin.area`	numeric Area of the drainage basin contributing water to the site where flow was monitored, if different from where concentration was monitored (as in `basin.area`).
`basin.area.units`	character Units of the values in `basin.area` and `flow.basin.area` (must be the same for both). Basin areas are used to compute yields as loads per contributing (basin) area.
`metadata`	the metadata object to update.
`new.metadata`	Optional object of class "metadata". If new.metadata is not NA, all elements of `...` will be ignored and metadata will be updated with any non-empty elements of new.metadata.
`...`	named arguments describing metadata elements to be modified; the names may be any of those accepted by `metadata()`.

By default, newly created metadata objects are checked for validity. This check may be bypassed by setting validate=FALSE. However, except where the user is only interested in using metadata objects in isolation (i.e., outside a load model), this option will rarely be appropriate.

Valid units options, loadflex style

Models used in loadflex require metadata with units in a standardized form. For any model not produced using rloadest functions, this standardized format is a space-separated list of text units with exponents denoted with "^". Valid examples include "mg L^-1", "ft^3 s^-1", "kg", and "colonies d^-1". Here is the full set of possibilites, separated by units type:

flow.units take the form VOLUME TIME^-1.

VOLUME: m^3, ft^3, dL, L
TIME: s, d, y

conc.units take the form MASS/VOLUME or COUNT/VOLUME.

MASS: ng, ug, mg, g, kg, Mg, lb, ton
COUNT: colonies, million_colonies
VOLUME: m^3, ft^3, dL, L

load.units take the form MASS or COUNT.

MASS: ng, ug, mg, g, kg, Mg, lb, ton
COUNT: colonies, million_colonies

load.rate.units take the form MASS/TIME or COUNT/TIME.

MASS: ng, ug, mg, g, kg, Mg, lb, ton
COUNT: colonies, million_colonies
TIME: s, d, y

#' basin.area.units take the form AREA.

AREA: m^2, ha, km^2, ft^2, ac, mi^2

For compatibility with rloadest models, metadata and updateMetadata also accept all those units accepted by rloadest (see next section).

Valid units options, rloadest style

Units passed to rloadest take the form "X/Y" or "X per Y" or an abbreviation and accept a limited number of numerators and denominators. Any valid rloadest units will be translated to valid loadflex units when supplied to loadReg2, metadata or updateMetadata. These rloadest-style units are currently accepted:

flow.units take the form VOLUME/TIME, VOLUME per TIME, or ABV.

VOLUME: cubic meter, cubic meters, m^3, cubic foot, cubic feet, ft^3, 100mL, dL, liter, l, L
TIME: second, sec, day, d, year, yr, y
ABV: cms, cfs

conc.units take the form MASS/VOLUME or COUNT/VOLUME.

MASS: nanograms, micrograms, milligrams, grams, kilograms, metric tons, ng, ug, mg, g, kg, Mg, tons, pounds, lbs, lb
COUNT: col, colonies, million colonies
VOLUME: cubic meter, cubic meters, m^3, cubic foot, cubic feet, ft^3, 100mL, dL, liter, l, L

load.units take the form MASS or COUNT.

MASS: nanograms, micrograms, milligrams, grams, kilograms, metric tons, ng, ug, mg, g, kg, Mg, tons, pounds, lbs, lb
COUNT: col, colonies, million colonies

load.rate.units are derived as load.units per day.

metadata returns a new metadata object with the specified entries.

updateMetadata returns a new metadata object that combines the values in the initial metadata with EITHER the non-empty elements of new.metadata OR the elements specified in ..., depending on whether new.metadata is provided.

Other metadata: metadata-getters

md <- metadata(constituent="NO3", flow="DISCHARGE", 
  dates="DATE", conc.units="mg L^-1", flow.units="cfs", load.units="kg", 
  load.rate.units="kg d^-1", site.name="Lamprey River, NH",
  site.id="1073500", custom=list(data_source="USGS NWIS, waterdata.usgs.gov"))
md1 <- metadata(constituent="NO3", flow="DISCHARGE", 
  dates="DATE", conc.units="mg L^-1", flow.units="cfs", load.units="kg", 
  load.rate.units="kg d^-1", site.name="Lamprey River, NH")
md2 <- updateMetadata(md1, site.id="1073500", 
  custom=list(data_source="USGS NWIS, waterdata.usgs.gov"))