create_attribute: Create Attribute

In CVPIA-OSC/EMLaide: Provides functions for building EML metadata for EDI's data repository

Create Attribute

Description

Create an attribute element according to EML standards.

Usage

create_attribute(
  attribute_name,
  attribute_definition,
  measurement_scale,
  attribute_label = NULL,
  domain = NULL,
  definition = NULL,
  text_pattern = NULL,
  type = NULL,
  units = NULL,
  number_type = NULL,
  unit_precision = NULL,
  date_time_format = NULL,
  date_time_precision = NULL,
  minimum = NULL,
  maximum = NULL
)

Arguments

attribute_name	The name of a field in a data table. This is often a short and/or cryptic name. It is recommended that the attribute names be suitable for use as a variable, e.g., composed of ASCII characters, and that the attribute names match the column headers of a CSV or other text table.
attribute_definition	A precise and complete definition of the attribute being documented.
measurement_scale	The type of scale from which values are drawn for the attribute. A list of approved measurement scales can be viewed at measurement_scale. Further explanation of the choices and required inputs are described below.
attribute_label	(Optional) Used to provide a less ambiguous or less cryptic alternative identification than what is provided in attribute_name.
domain	Input for the non-numeric measurement scales only. Please list either "text" or "enumerated".
definition	Either the text definition or code definition. Both are appended using this parameter, but have different applications. Examples of both are listed below.
text_pattern	(Optional) A regular expression pattern constraining the attribute.
type	Either "ratio" or "interval".
units	The units assigned to this attribute's values.
number_type	A list of possible options can be viewed at number_type.
unit_precision	(Optional) How precise units are measured.
date_time_format	The format your date/time attribute is recorded in. ISO 8601 standard should be used (YYYY-MM-DD).
date_time_precision	To what level time is being measured.
minimum	Theoretical or allowable minimum value. Values can be larger than or equal to this number.
maximum	Theoretical or allowable maximum value. Values can be less than or equal to this number.

Value

An attribute list

Measurement Scales

Different measurement scale values will indicate different inputs:

Non-numeric:

Please provide a domain to indicate if your attribute is text or enumerated.

Nominal: Used to define categorical scale attributes. If your attribute falls under the domain of "text", please provide the inputs of definition and text_pattern. If your attribute falls under the domain of "enumerated", please provide the input of definition.

Ordinal: Used to define ordered scale attributes. If your attribute falls under the domain of "text", please provide the inputs of definition and text_pattern. If your attribute falls under the domain of "enumerated", please provide the input of definition.

Numeric:

Interval: Used to define interval scale attributes. Please provide the inputs of type, units, unit_precision, number_type, minimum, and maximum.

Ratio: Used to define ratio scale attributes. Please provide the inputs of type, units, unit_precision, number_type, minimum, and maximum.

dateTime: Used to define date and time attributes. Please provide the inputs of date_time_format, date_time_precision, minimum, and maximum.

Examples

# Nominal(text):
## Not run: create_attribute(attribute_name = "site_id",
                          attribute_definition = "Site id as used in sites table",
                          measurement_scale = EMLaide::measurement_scale$nominal,
                          domain= "text",
                          definition = "Site id as used in sites table.")
## End(Not run)

# Nominal(enumerated):
code_def_1 = list(code = "yes", definition = "has been captured previously")
code_def_2 = list(code = "no", definition = "has not been captured previously")
code_definition = list(code_def_1, code_def_2)
## Not run: create_attribute(attribute_name = "Recap", 
                          attribute_definition = "Has the Turtle been captured and tagged previously",
                          measurement_scale = EMLaide::measurement_scale$nominal, 
                          domain = "enumerated",
                          definition = code_definition)
## End(Not run)
              
# Ordinal(text):
## Not run: create_attribute(attribute_name = "LatitudeDD", 
                          attribute_definition = "Latitude",
                          measurement_scale = EMLaide::measurement_scale$ordinal,
                          domain= "text", 
                          definition = "Latitude")
## End(Not run)
              
# Ordinal(enumerated): 
code_def_0 = list(code = "0", definition = "0 insects per meter of branch")
code_def_1 = list(code = "1", definition = "1-10 insects per meter")
code_def_2 = list(code = "2", definition = "11 – 100 insects per meter")
code_def_3 = list(code = "3", definition = "more than 100 insects per meter")
code_definition = list(code_def_0, code_def_1, code_def_2, code_def_3)
## Not run: create_attribute(attribute_name = "hwa",
                          attribute_definition = "Hemlock woolly adelgid density per meter of branch",
                          measurement_scale = EMLaide::measurement_scale$ordinal,
                          domain = "enumerated",
                          definition = code_definition)
## End(Not run)
              
# Interval:
## Not run: create_attribute(attribute_name = "Count",
                          attribute_definition = "Number of individuals observed",
                          measurement_scale = EMLaide::measurement_scale$interval, 
                          type = "interval",
                          units = "number",
                          unit_precision = "1",
                          number_type = EMLaide::number_type$whole, 
                          minimum = "0")
## End(Not run)
                   
# Ratio: 
## Not run: create_attribute(attribute_name = "pH",
                          attribute_definition = "pH of soil solution",
                          measurement_scale = EMLaide::measurement_scale$ratio,
                          type = "ratio",
                          units = "dimensionless",
                          unit_precision = "0.01",
                          number_type = EMLaide::number_type$real)
## End(Not run)
                   
# dateTime:
## Not run: create_attribute(attribute_name = "Yrs", 
                          attribute_definition = "Calendar year of the observation from years 1990 - 2010.",
                          measurement_scale = EMLaide::measurement_scale$dateTime,
                          attribute_label = "Years",
                          date_time_format = "YYYY", 
                          date_time_precision = "1", 
                          minimum = "1993", 
                          maximum = "2003")
## End(Not run)

CVPIA-OSC/EMLaide documentation built on Aug. 25, 2023, 8:53 a.m.