calculateAvailability: Aggregate Availability

In SWS-Methodology/faoswsStandardization: Package to perform standardization of SUA (supply utilization account) data to FBS level

Description

In order to determine shares for standardization, we have to calculate availability of parent commodities. For example, if fruit juice is produced from both apples and oranges, and the country has 400 tonnes of apples and 100 tonnes of oranges, then we should standardize 80 to apples and 20 consider the multiple levels of the tree, and that there may be trade of flour, for example, which influences the availability of wheat.

Usage

calculateAvailability(tree, standParams)

Arguments

tree	The commodity tree, specified as a data.table object. It should have columns childVar (the commodity code of the child), parentVar (the commodity code of the parent), extractionVar (numeric value specifying the extraction rate), and possibly shareVar (numeric value specifying how the commodity should be split up), all of which are specified in standParams.
standParams	The parameters for standardization. These parameters provide information about the columns of data and tree, specifying (for example) which columns should be standardized, which columns represent parents/children, etc.

Details

Note that availability becomes complicated with complicated graphs. For example, if A is a parent of B and C, and B and C are both parents of D, what is the availability of A for standardizing D? There is no clear best approach, but we decided to compute availability of A for D in this case by computing the availability of A, B, and C for D (i.e. aggregating the imbalances over all parents in the path). In the case of A and B are parents of C and C is a parent of D, we have a different problem. Imbalances in C shouldn't be double counted in the imbalances of A and B, so we should split C's imbalance into A and B according to availability of A and B.

Value

A data.table with columns parentVar, childVar, and the availability from that process. Thus, if beer could be standardized into wheat, maize or barley (and there is availability in all three products) our final table will have three rows (beer/wheat, beer/maize, beer/barley).

SWS-Methodology/faoswsStandardization documentation built on Feb. 7, 2022, 5:05 a.m.