# Time series / Floor and Multiplier

The Floor and Multiplier construction usually represents a decaying exponential, starting from 1 in the Base Period, falling to the Floor as time increases. It is commonly used to specify normalised data, such as Cost Indices and Running Cost Trends; but can also be used to generate a trend which rises to the Floor. A Floor and Multiplier is equivalent to a fixed component, Constant = f, plus a variable component, a complementary Exponential Growth with b = 1 – f.

## Floor

The fixed component, usually between 0 and 1. The asymptotic value of the time series if the Multiplier is less than 1.

Default: 0.0.

## Multiplier (1)

An amount which multiplies the previous year’s value in each year. A value of 1.05 represents 5% annual growth, while a value of 0.95 represents a 5% decline. The Multiplier parameter must be positive, and no greater than 2.

For a Floor, the Multiplier indicates how fast the curve converges to the specified Floor. A lower value will create a steep decline towards the Floor in the early years.

Default: 1.0.

## Base Period

Specifies a particular period when the Base value should apply. This can be a year, a quarter, a month, or even a fully-qualified date.

Default: Y0.

Options

## Alignment

Determines what point in the Base Period or Period the Base value or corresponding values is/are associated with.

Default: End for demand-related inputs, but Beginning for tariffs and cost trends.

## Step (1)

Constrains the dynamics of any time-series input to yield a constant value for quarterly, annual or even indefinite periods.

Default: Day (no constraint is applied: values evolve smoothly).