Localize.Unit.Conversion.Beaufort (Localize v1.4.2)

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Nonlinear conversion between the Beaufort wind force scale and meters per second.

TR35 names this conversion special and does not define it: "The only special conversion currently supported is for beaufort". It is done here by interpolating between the midpoints of the WMO-defined speed thresholds for each Beaufort number, as ICU does it, which gives the value CLDR's unit test data has.

Registered as a :special custom unit so that the generic conversion pipeline dispatches through forward/1 and inverse/1 rather than using factor-based arithmetic.

Summary

Functions

forward(beaufort)

Converts a Beaufort scale value to meters per second.

inverse(mps)

Converts meters per second to a Beaufort scale value.

Functions

forward(beaufort)

@spec forward(number()) :: float()

Converts a Beaufort scale value to meters per second.

Values are clamped to the range [0, 17]. Fractional Beaufort numbers are interpolated between adjacent midpoints.

Arguments

  • beaufort is a Beaufort scale number.

Returns

  • The speed in meters per second, as a float.

Examples

iex> Localize.Unit.Conversion.Beaufort.forward(0)
0.15

iex> Localize.Unit.Conversion.Beaufort.forward(5)
9.4

inverse(mps)

@spec inverse(number()) :: float()

Converts meters per second to a Beaufort scale value.

Finds the Beaufort band whose midpoint range contains the given speed and interpolates within it. Negative speeds return 0.0.

Arguments

  • mps is a speed in meters per second.

Returns

  • The Beaufort scale value, as a float.

Examples

iex> Localize.Unit.Conversion.Beaufort.inverse(9.4)
5.0

iex> Localize.Unit.Conversion.Beaufort.inverse(-3)
0.0