standard: Get standard table

Description

Download data from the standard ("febr-padrao") table of the Free Brazilian Repository for Open Soil Data

febr, http://www.ufsm.br/febr. This includes codes and names of variable, measurement units, number of decimal places, type of data, and description of analytical methods. This is used to standardize the data contained in a dataset when downloading it via layer or observation.

Usage

standard(table, variable, unit, precision, expr)

Arguments

table

(optional) Character string indicating a table, i.e. the layer table, "camada", or the observation table, "observacao".

variable

(optional) Character vector indicating one or more variables. Accepts both specific identification codes, e.g. "ferro_oxalato_icpoes" and "carbono_cromo_30min150_mohr", as well as general identification codes, e.g. "ferro" and "carbono".

unit

(optional) Character vector indicating one or more measurement units. For example, "g/kg", "g/cm^3", and "cmolc/kg".

precision

(optional) Integer vector indicating one or more number of decimal places.

expr

(optional) Character string to be parsed and evaluated as a regular expression. For example, "campo_precisao > 0". Usage requires some knowledge of the structure of the standard table.

Value

A data frame with standards for selected variable(s).

References

Teixeira, P. C., Donagemma, G. K., Fontana, A., Teixeira, W. G. (2017) Manual de M<U+00E9>todos de An<U+00E1>lise de Solo. Bras<U+00ED>lia: Embrapa.

Examples

Run this code

# NOT RUN {
res <- standard(variable = "ferro")
head(res)
# }