Melt a bilateral trade matrix to long format.

Convert the bilateral_trade list-column of get_bilateral_trade() (one square origin-by-destination matrix per year and item) into the tidy from_code/to_code long form consumed by compute_footprint_balance(). Self-trade (diagonal) entries are dropped.

Usage

melt_bilateral_trade(bilateral_trade)

Arguments

bilateral_trade

Tibble from get_bilateral_trade(), with year, item_cbs_code and a bilateral_trade matrix list-column.

Value

A tibble with year, from_code, to_code, item_cbs_code and value.

Examples

m <- matrix(
  c(0, 40, 0, 0),
  nrow = 2,
  dimnames = list(c("1", "2"), c("1", "2"))
)
bt <- tibble::tibble(
  year = 2010L, item_cbs_code = 10L, bilateral_trade = list(m)
)
melt_bilateral_trade(bt)
#> # A tibble: 1 × 5
#>    year from_code to_code item_cbs_code value
#>   <int>     <int>   <int>         <int> <dbl>
#> 1  2010         2       1            10    40