Geo.Turf.Math (geo_turf v0.5.0)

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All sorts of mathematical functions

Summary

Types

area_unit()

Unit accepted by area conversions.

imperial_length()

Imperial and nautical length units.

length_unit()

Unit accepted by geodesic length and distance calculations.

si_length_uk()

British-spelling SI length units.

si_length_us()

Alternative-spelling SI length units.

Functions

approx(point, precision \\ 4)

Rounds the coordinates of a Point to the given precision. Useful for approximate comparisons in tests. The returned Point preserves the source Point's SRID and properties.

bearing_to_azimuth(bearing)
convert_area(area, from \\ :meters, to \\ :kilometers)
convert_length(length, from \\ :kilometers, to \\ :kilometers)
degrees_to_radians(degrees)
length_to_degrees(length, units \\ :kilometers)
length_to_radians(length, unit \\ :kilometers)
mod(number, modulus)

Calculates the modulo of a number (integer or float).

radians_to_degrees(radians)
radians_to_length(radians, unit \\ :kilometers)
rounded(number, precision \\ 0)

Round number to precision

Types

area_unit()

@type area_unit() ::
  :acres
  | :centimeters
  | :centimetres
  | :feet
  | :inches
  | :kilometers
  | :kilometres
  | :meters
  | :metres
  | :miles
  | :millimeters
  | :millimetres
  | :yards

Unit accepted by area conversions.

imperial_length()

@type imperial_length() :: :miles | :nauticalmiles | :inches | :yards | :feet

Imperial and nautical length units.

length_unit()

@type length_unit() ::
  si_length_uk() | si_length_us() | imperial_length() | :degrees | :radians

Unit accepted by geodesic length and distance calculations.

si_length_uk()

@type si_length_uk() :: :meters | :kilometers | :centimeters | :millimeters

British-spelling SI length units.

si_length_us()

@type si_length_us() :: :metres | :kilometres | :centimetres | :millimetres

Alternative-spelling SI length units.

Functions

approx(point, precision \\ 4)

@spec approx(Geo.Point.t(), non_neg_integer()) :: Geo.Point.t()

Rounds the coordinates of a Point to the given precision. Useful for approximate comparisons in tests. The returned Point preserves the source Point's SRID and properties.

Examples

iex> Geo.Turf.Math.approx(%Geo.Point{coordinates: {1.23456, 7.89012}}, 3)
%Geo.Point{coordinates: {1.235, 7.89}}

bearing_to_azimuth(bearing)

@spec bearing_to_azimuth(number()) :: number()

convert_area(area, from \\ :meters, to \\ :kilometers)

@spec convert_area(number(), area_unit(), area_unit()) :: number()

convert_length(length, from \\ :kilometers, to \\ :kilometers)

@spec convert_length(number(), length_unit(), length_unit()) :: number()

degrees_to_radians(degrees)

@spec degrees_to_radians(number()) :: float()

length_to_degrees(length, units \\ :kilometers)

@spec length_to_degrees(number(), length_unit()) :: float()

length_to_radians(length, unit \\ :kilometers)

@spec length_to_radians(number(), length_unit()) :: float()

mod(number, modulus)

@spec mod(number(), number()) :: number()

Calculates the modulo of a number (integer or float).

Note that this function uses floored division whereas the builtin rem function uses truncated division. See Decimal.rem/2 if you want a truncated division function for Decimals that will return the same value as the BIF rem/2 but in Decimal form.

See Wikipedia for an explanation of the difference.

Taken from cldr_utils with thanks and gratitude.

Examples

iex> Geo.Turf.Math.mod(1234.0, 5)
4.0

radians_to_degrees(radians)

@spec radians_to_degrees(number()) :: float()

radians_to_length(radians, unit \\ :kilometers)

@spec radians_to_length(number(), length_unit()) :: number()

rounded(number, precision \\ 0)

Round number to precision

Example

iex> Geo.Turf.Math.rounded(120.4321)
120

iex> Geo.Turf.Math.rounded(120.4321, 3)
120.432