An S4 class to represent commodity export to the rest of the world.

Export object represent commodity export to the Rest of the World (RoW).

The method replaces slots of the export object with new values.

Details

export is a type of process that adds an "external" source to a commodity to the model. The Rest of the World (RoW) is not modeled explicitly, export and import objects define and control the exchange with the RoW. The operation of the export object is similar to the demand objects, the two different classes are used to distinguish domestic and external sources of final consumption. The export is controlled by the exp data frame, which specifies bounds and fixed values for the export of the export flow. The exp.fx column is used to specify fixed values of the export flow, making the export flow exogenous. The exp.lo and exp.up columns are used to specify lower and upper bounds of the export flow, making the export flow endogenous. The price column is used to specify the exogenous price for the export commodity. The reserve slot is used to set limits on the total export over the model horizon.

Slots

name

character. Name of the export object, used in sets.

desc

character. Description of the export object.

commodity

character. Name of the exported commodity.

unit

character. Unit of the exported commodity.

reserve

data.frame. Cumulative limit over the whole model horizon, summed across ALL regions, years and timeslices. A data.frame (rather than the bare number it was before 0.85) so it can carry a cluster column and be split across price steps; without that every step would inherit the FULL limit and the model would quietly hold nsteps times the resource. A plain number is still accepted by the constructor and read as res.up. There is deliberately no region column: adding one would turn this into a per-region cap and LOSE the all-region total, which is what it means today.

cluster: character. Price step this row applies to, NA for every step.
res.lo: numeric. Lower bound on the cumulative volume.
res.up: numeric. Upper bound on the cumulative volume.
res.fx: numeric. Fixed cumulative volume. Overrides res.lo and res.up.

cluster

data.frame. Declaration of the object's parallel sub-objects. For export a cluster is a PRICE STEP of a stepped curve: its own share of the quantity, at its own price. A single price cannot express a curve – real resource grades get dearer as they are exhausted, and a real export market pays less as more volume is pushed into it. This slot declares WHAT the steps are; the per-step values live in the cluster column of the other slots. Build both with asExportCurve(), which also computes the prices and checks the direction of the curve. Optional. When empty, step labels are harvested from the cluster columns of the other slots. When populated it is AUTHORITATIVE. LIMITATION – there is deliberately no cap.share.fx column. A capacity share ties the variants' capacities to fixed proportions, and this class has no capacity variable for the tie to act on. The column is absent rather than present-and-ignored, so the mistake is rejected at construction instead of silently doing nothing. Bound the split with act.share.lo/up/fx, which acts on the quantity this class does have, or fix it directly in the per-step bounds. The share columns are different levers, not substitutes. cap.share.fx fixes the ratio of the variants' CAPACITIES in every year: loss tranches need it, because each tranche efficiency is calibrated to its place in the capacity stack and the flow must stay free to fill the cheapest first. act.share.lo/up/fx bounds a variant share of the family THROUGHPUT instead, which is what stops a clustered family collapsing to its cheapest member once regional borders are aggregated away. Both are optional; a variant with neither sizes and runs freely.

cluster: character. Step label, used in the expanded object name.
desc: character. Description of the step.
share: numeric. The step's fraction of the object's quantity. DESCRIPTIVE, not enforced: unlike technology or trade this class has no capacity variable to tie, so asExportCurve() writes the split straight into the quantity bounds and records here what it did.
order: integer. Fill order, 1 = the cheapest step (or, for export, the best paid). Without it labels sort alphabetically and "S10" would precede "S2".

export

data.frame. Export parameters.

cluster: character. Price step this row applies to, NA for every step. See the cluster slot.
region: character. Region name to apply the parameter; use NA to apply to all regions.
year: integer. Year to apply the parameter; use NA to apply to all years.
timeslice: character. Time timeslice to apply the parameter; use NA to apply to all timeslices.
exp.lo: numeric. Export lower bound.
exp.up: numeric. Export upper bound.
exp.fx: numeric. Fixed export volume, ignored if NA. This parameter overrides exp.lo and exp.up.
price: numeric. Price received per unit exported. Export revenue is a NEGATIVE cost – the minus sits inside eqExportRowCost – so a higher price is a better outcome for the objective.

region

character. Regions where the export process exists. Empty (or NA) means every region of the model. A region named in any other slot must be one of these; the other slots place VALUES and never change where the process exists.

misc

list. Additional information.