costs.scaleAlpha: Helper function to modify alpha costs of an insurance contract individually
Description
Returns a function that modifies alpha (and Zillmer) costs by the given scale,
but otherwise uses the full costs defined by the Costs parameter.
Usage
costs.scaleAlpha(scale)
Arguments
scale
The scale for alpha / Zillmer cost
Details
This function can be set as adjustCosts or adjustMinCosts hook parameters
for a tariff or contract and can be used to apply cost adjustments on a
per-contract basis.