Construct period-over-period price relatives from information on prices and
products over time.
Usage
price_relative(x, ...)
# S3 method for default
price_relative(x, ..., period, product)
# S3 method for data.frame
price_relative(x, formula, ...)
Value
A numeric vector of price relatives, with product as names.
Arguments
x
Either a numeric vector (or something that can be coerced into one)
or data frame of prices.
...
Further arguments passed to or used by methods.
period
A factor, or something that can be coerced into one, that
gives the corresponding time period for each element in x. The
ordering of time periods follows the levels of period to agree with
cut().
product
A factor, or something that can be coerced into one, that
gives the corresponding product identifier for each element in x.
formula
A two-sided formula with prices on the left-hand
side, and time periods and products (in that order) on the
right-hand side.
See Also
gpindex::back_period() to get only the back price.
gpindex::base_period() for making fixed-base price relatives.
carry_forward() and shadow_price() to impute missing prices.
gpindex::outliers for methods to identify outliers with price relatives.