rs_pairs: Sales pairs

In rsmatrix: Matrices for Repeat-Sales Price Indexes

Sales pairs

Description

Turn repeat-sales data into sales pairs that are suitable for making repeat-sales matrices.

Usage

rs_pairs(period, product, match_first = TRUE)

Arguments

period	A vector that gives the time period for each sale. Usually a date vector, or a factor with the levels in chronological order, but other values are possible if they can be sorted in chronological order (i.e., with order()).
product	A vector that gives the product identifier for each sale. Usually a factor or vector of integer codes for each product.
match_first	Should products in the first period match with themselves (the default)?

Value

A numeric vector of indices giving the position of the previous sale for each product, with the convention that the previous sale for the first sale is itself if match_first = TRUE, NA otherwise. Ties are resolved according to the order they appear in period.

Note

order() is the workhorse of rs_pairs(), so performance can be sensitive to the types of period and product, and can be slow for large character vectors.

See Also

rs_matrix() for using sales pairs to make a repeat-sales index.

rtCreateTrans() in the hpiR package for a feature-rich but slower and less flexible function to make sales pairs.

Examples

# Make sales pairs
x <- data.frame(
  id = c(1, 1, 1, 3, 2, 2, 3, 3),
  date = c(1, 2, 3, 2, 1, 3, 4, 1),
  price = c(1, 3, 2, 3, 1, 1, 1, 2)
)

pairs <- rs_pairs(x$date, x$id)

x[c("date_prev", "price_prev")] <- x[c("date", "price")][pairs, ]

x

rsmatrix documentation built on April 3, 2025, 7:20 p.m.