common library

Common codes, constants, functions, presentation helpers and reference systems related to geospatial applications.

Features:

Enums (codes): geospatial coordinate, geometry types, dimensionality, canvas origin, cardinal direction, DMS type, geo representation, axis order, hemisphere, coordinate reference system types.
Constants: epsilon, geodetic and screen related constants.
Conversions: angle, angular velocity, area, distance, speed and time.
Functions: conversions between units, geographic coordinate helpers.
Presentation: DMS (degree-minutes-seconds geographic representations).
Reference: Coordinate and temporal reference systems. Reference ellipsoids.

This libary exports a subset of package:geobase/geobase.dart.

Usage: import package:geobase/common.dart

Examples on unit conversions:

  // Length units (mm, cm, m, km, in, ft, yd, mi, nmi), with some examples:
  const meters = 1500.0;
  meters.convertLength(to: LengthUnit.foot); // ~ 4921.26 ft
  meters.convertLength(to: LengthUnit.kilometer); // 1.5 km
  meters.convertLength(to: LengthUnit.nauticalMile); // 0.8099 nmi
  254.convertLength(from: LengthUnit.millimeter, to: LengthUnit.inch); // 10.0

  // Area units (mm², cm², m², km², in², ft², yd², mi², ac, ha), with examples:
  const squareMeters = 10000.0;
  squareMeters.convertArea(to: AreaUnit.squareKilometer); // 0.01 km²
  squareMeters.convertArea(to: AreaUnit.acre); // ~ 2.4711 acres
  1.0.convertArea(
    from: AreaUnit.hectare,
    to: AreaUnit.squareFoot,
  ); // 107639.1042 ft²

  // Speed units (mm/s, cm/s, m/s, km/h, mph, ft/s, kn), with some examples:
  const metersPerSecond = 10.0;
  metersPerSecond.convertSpeed(to: SpeedUnit.kilometerPerHour); // 36.0 km/h
  metersPerSecond.convertSpeed(to: SpeedUnit.milePerHour); // 22.3694 mph
  10.0.convertSpeed(
    from: SpeedUnit.kilometerPerHour,
    to: SpeedUnit.knot,
  ); // ~ 5.3996 kn

  // Angle units (mrad, rad, arcsec, arcmin, deg, gon, turn), with examples:
  const degrees = 90.0;
  degrees.convertAngle(from: AngleUnit.degree); // ~1.5708 rad
  degrees.convertAngle(from: AngleUnit.degree, to: AngleUnit.gradian); // 100.0

  // Angular velocity units (mrad/s, rad/s, deg/s, rpm, rps), with examples:
  const radiansPerSecond = 1.0;
  radiansPerSecond.convertAngularVelocity(
    to: AngularVelocityUnit.degreePerSecond,
  ); // ~ 57.296 deg/s
  720.0.convertAngularVelocity(
    from: AngularVelocityUnit.degreePerSecond,
    to: AngularVelocityUnit.revolutionPerSecond,
  ); // 2.0 rps

  // Time units (ns, µs, ms, s, min, h, d, w), with some examples:
  const seconds = 3600.0;
  seconds.convertTime(to: TimeUnit.hour); // 1.0 h
  seconds.convertTime(to: TimeUnit.day); // 0.0417 d
  1.0.convertTime(from: TimeUnit.week, to: TimeUnit.day); // 7.0 d

Classes

CoordRefSys: Metadata about a coordinate reference system (CRS) identified and specified by id.
CoordRefSysResolver: An abstract class for resolving coordinate reference system information.
Dms: A default implementation for DmsFormat abstract base class, that defines methods for parsing and formatting degrees/minutes/seconds on latitude, longitude and bearing values.
DmsFormat: A base class for formatters with methods for parsing and formatting degrees/minutes/seconds on latitude, longitude and bearing values.
Ellipsoid: A reference ellipsoid with ellipsoidal parameters (a, b and f).
TemporalRefSys: Metadata about a temporal coordinate reference system (TRS) identified and specified by id.
TemporalRefSysResolver: An abstract class for resolving temporal coordinate reference system information.

Enums

AngleUnit: An enumeration of angle units.
AngularVelocityUnit: An enumeration of angular velocity units.
AreaUnit: An enumeration of area units.
AxisOrder: The axis order of coordinate values in position and point representations.
CanvasOrigin: The position of the origin in a canvas or a grid.
CardinalPrecision: The precision for cardinal directions (compass point).
CoordRefSysType: An enumeration of common coordinate reference system (CRS) types.
Coords: An enum for coordinate types (by spatial dimension and whether is measured).
Dimensionality: An enum for dimensionality or topological dimension in the context of geospatial applications.
DmsType: An enum for common representation of geographic positions by coordinates (using degrees, minutes and seconds as components).
Geom: An enum for geometry types.
GeoRepresentation: An enum for spatial representations that can be used to code logic when need to choose some options based on a representation.
Hemisphere: An enum representing the hemispheres of the Earth.
LengthUnit: An enumeration of length (distance) units.
SpeedUnit: An enumeration of speed units.
TimeUnit: An enumeration of time units (representing values of time duration or intervals).

Extensions

DoubleAngleExtension on double: An extension on double with basic degrees and radians utility methods.
GeographicDoubleAngleExtension on double: An extension on double with basic degrees and radians utility methods ( (for geographic coordinate reference systems).
UnitConversionExtension on num: An extension on double with conversion methods for angle, angular velocity, area, length, speed and time units.

Constants

defaultEpsilon → const double: The default epsilon value 1.0e-9 used as a tolerance in equals2D, equals3D and similar methods in this package.
doublePrecisionEpsilon → const double: The maximum relative precision of double numbers (IEEE 754).
earthCircumferenceWgs84 → const double: The earth circumference in meters (from earth equatorial radius by WGS 84).
earthRadiusWgs84 → const double: The earth equatorial radius in meters as specified by WGS 84.
maxLatitude → const double: The maximum value for the geographic latitude.
maxLatitudeUTM → const double: The maximum value for the geographic latitude inside the Universal Transverse Mercator (UTM) projection coverage.
maxLatitudeWebMercator → const double: The maximum value for the geographic latitude inside the Web Mercator projection coverage.
maxLongitude → const double: The maximum value for the geographic longitude.
minLatitude → const double: The minimum value for the geographic latitude.
minLatitudeUTM → const double: The minimum value for the geographic latitude inside the Universal Transverse Mercator (UTM) projection coverage.
minLatitudeWebMercator → const double: The minimum value for the geographic latitude inside the Web Mercator projection coverage.
minLongitude → const double: The minimum value for the geographic longitude.
screenPPIbyOGC → const double: OGC defines a screen pixel of 0.28 mm that approximates to 90.7 ppi.

common library

Classes

Enums

Extensions

Constants

geobase package

common library