Denominate.data.frame: Denominate data sets by other variables

Description

"Denominates" or "scales" variables by other variables. Typically this is done by dividing extensive variables such as GDP by a scaling variable such as population, to give an intensive variable (GDP per capita).

Usage

# S3 method for data.frame
Denominate(
  x,
  denoms,
  denomby,
  x_ID = NULL,
  denoms_ID = NULL,
  f_denom = NULL,
  ...
)

Value

A data frame of the same size as x, with any specified columns denominated according to specifications.

Arguments

x: A data frame of data to be denominated. Columns to be denominated must be numeric, but any columns not specified in denomby will be ignored. x must also contain an ID column specified by x_ID to match rows with denoms.
denoms: A data frame of denominator data. Columns should be denominator data, with column names corresponding to entries in denomby. This must also include an ID column identified by denoms_ID to match rows.
denomby: A data frame which specifies which denominators to use for each indicator, and any scaling factors to apply. Should have columns iCode, Denominator, ScaleFactor. iCode specifies a column name from x, Denominator specifies a column name from denoms to use to denominate the corresponding column from x. ScaleFactor allows the possibility to scale denominators if needed, and specifies a factor to multiply the resulting values by. For example, if GDP is a denominator and is measured in dollars, dividing will create very small numbers (order 1e-10 and smaller) which could cause problems with numerical precision.
x_ID: A column name of x to use to match rows with denoms. Default is "uCode".
denoms_ID: A column name of denoms to use to match rows with x. Default is "uCode".
f_denom: A function which takes two numeric vector arguments and is used to perform the denomination for each column. By default, this is division, i.e. x[[col]]/denoms[[col]] for given columns, but any function can be passed that takes two numeric vectors as inputs and returns a single numeric vector. See details.
...: arguments passed to or from other methods.

Details

A data frame x is denominated by variables found in another data frame denoms, according to specifications in denomby. denomby specifies which columns in x are to be denominated, and by which columns in denoms, and any scaling factors to apply to each denomination.

Both x and denomby must contain an ID column which matches the rows of x to denomby. If not specified, this is assumed to be uCode, but can also be specified using the x_ID and denoms_ID arguments. All entries in x[[x_ID]] must be present in denoms[[denoms_ID]], although extra rows are allowed in denoms. This is because the rows of x are matched to the rows of denoms using these ID columns, to ensure that units (rows) are correctly denominated.

By default, columns of x are divided by columns of denoms. This can be generalised by setting f_denom to another function which takes two numeric vector arguments. I.e. setting denoms = ``*`` will multiply columns of x and denoms together.

Examples

Run this code

# Get a sample of indicator data (note must be indicators plus a "UnitCode" column)
iData <- ASEM_iData[c("uCode", "Goods", "Flights", "LPI")]
# Also get some denominator data
denoms <- ASEM_iData[c("uCode", "GDP", "Population")]
# specify how to denominate
denomby <- data.frame(iCode = c("Goods", "Flights"),
Denominator = c("GDP", "Population"),
ScaleFactor = c(1, 1000))
# Denominate one by the other
iData_den <- Denominate(iData, denoms, denomby)