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DemandAndConversions

The DemandAndConversions module takes parameters for e.g. population, diets, demand for non-food and export uses and waste and conversion factors to calculate total national demand for crop (crop_prod) and animal products (animal_prod), by-products (by_prod) and crop residues (crop_resid) as well as generated by-products, wastes and import demand.

Supply and demand for dairy fats are balanced with the _fix_cream_balance() helper function that induce exports of low- or high-fat dairy products to resolve the balance.


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flowchart TD

  %% -------------------------
  %% Main orchestration
  %% -------------------------
  A["<b>DemandAndConversions</b>"]:::mod_main --> C["<b>.calculate()</b>"]:::method

  C --> GP["<b>.get_population()</b>"]:::method
  FD["<b>.calculate_food_demand()</b>"]:::method
  NFX["<b>.get_non_food_and_export_demand()</b>"]:::method

  %% Resolve recipes for multiple demand tables
  RR["<b>.resolve_recipies()</b>"]:::method

  W["<b>.calculate_waste()</b>"]:::method
  NS["<b>.calculate_nutrient_supply()</b>"]:::method
  PD["<b>.calculate_product_demand_and_by_products()</b>"]:::method


  %% -------------------------
  %% Population
  %% -------------------------
  P_POP["<b>DemandAndConversions.par.</b>
  population, population_region"]:::param --> GP

  GP --> DA_POP["<b>DemandAndConversions.data_attr.</b>
  population, population_per_region"]:::data
  DA_POP --> FD


  %% -------------------------
  %% Food demand (diet -> kg/year by origin & production system)
  %% -------------------------
  P_CONS["<b>DemandAndConversions.par.</b>
consumption, share_imported, share_in_prod_system"]:::param --> FD

  FD --> DA_FD["<b>DemandAndConversions.data_attr.</b>
  food_demand"]:::data
  DA_FD ---> W
  DA_FD ---> NS

  %% -------------------------
  %% Non-food + Export demand
  %% -------------------------
  P_NFX["<b>DemandAndConversions.par.</b>
non_food_demand, export_demand"]:::param --> NFX

  NFX ---> DA_NFX["<b>DemandAndConversions.data_attr.</b>
  non_food_demand, export_demand"]:::data

  %% -------------------------
  %% Waste calculation (stage losses)
  %% -------------------------
  P_WASTE["<b>DemandAndConversions.par.</b>
waste_share"]:::param --> W
  W ---> DA_FTP["<b>DemandAndConversions.data_attr.</b>
  food_demand_to_processing, waste"]:::data

  %% -------------------------
  %% Nutrient supply (diet composition)
  %% -------------------------
  P_COMP["<b>DemandAndConversions.par.</b>
composition"]:::param --> NS
  NS --> DA_NDA_NS["<b>DemandAndConversions.data_attr.</b>
  nutrient_supply"]:::data

  %% -------------------------
  %% Recipe resolution (compound foods -> ingredients)
  %% -------------------------
  RR --> PD
  P_REC["<b>DemandAndConversions.par.</b>
recipie"]:::param --> RR

  %% -------------------------
  %% Product demand & by-products
  %% -------------------------
  P_CF["<b>DemandAndConversions.par.</b>
conv_factor_main, conv_factor_by"]:::param --> PD

  %% Inputs to demand aggregation
  DA_FTP --> PD
  DA_NFX --> PD

  %% Outputs
  PD ---> DA_CPD["<b>DemandAndConversions.data_attr.</b>
  crop_prod_demand, animal_prod_demand, crop_resid_demand, by_prod_demand,
  by_products, by_prod_per_crop_prod, by_prod_per_animal_prod"]:::data

  %% (Optional) internal helper logic (not class methods)
  PD_H["_get_demand()
  _fix_cream_balance()
  _attribute_secondary_by_prod()
  "]:::helper --> PD



  %% -------------------------
  %% Styles
  %% -------------------------
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  classDef settings fill:#ffd5f680,stroke:#aa0088,stroke-width:1px,font-size:11,color:#aa0088;
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View Docstring 
Signature:
DemandAndConversions(par: ParameterRetriever)

Docstring:
Class that calculates demand for domestic and imported crop and animal products, as
well as generated food waste and by-products etc. A per capita diet is defined in
the parameter Excel sheet along with parmeters for import shares, conversion
factors, waste levels, etc.

Parameters
----------
par : ParameterRetriever object

Attributes set on init
----------------------
None

Attributes set by FoodDemand.calculate()
----------------------------------------
population : int [millions]
food_demand : pandas.DataFrame [kg/year]
    Demand for food per production system and origin (domestic, imported)
food_demand_to_processing : pandas.DataFrame [kg/year]
    Food demand after accounting for household, retail and processing wastes
crop_prod_demand : pandas.DataFrame
crop_by_products : pandas.DataFrame
animal_prod_demand : pandas.DataFrame
animal_by_products : pandas.DataFrame
waste : pandas.DataFrame [kg/year]
    Generated waste at household, retail and processing. Only includes domestically
    generated waste assuming that processing waste for imported foods occur abroad.

File: CIBUSmod/main_modules/demand_and_conversions.py