Package ucar.nc2.dataset

Class CoordinateSystem

java.lang.Object
ucar.nc2.dataset.CoordinateSystem
public class CoordinateSystem extends Object
A CoordinateSystem specifies the coordinates of a Variable's values. Mathematically it is a vector function F from index space to Sn: 
  F(i,j,k,...) -> (S1, S2, ...Sn)
  where i,j,k are integers, and S is the set of reals (R) or Strings.
The components of F are just its coordinate axes: 
  F = (A1, A2, ...An)
    A1(i,j,k,...) -> S1
    A2(i,j,k,...) -> S2
    An(i,j,k,...) -> Sn
Concretely, a CoordinateSystem is a set of coordinate axes, and an optional set of coordinate transforms. The domain rank of F is the number of dimensions it is a function of. The range rank is the number of coordinate axes.

An important class of CoordinateSystems are georeferencing Coordinate Systems, that locate a Variable's values in space and time. A CoordinateSystem that has a Lat and Lon axis, or a GeoX and GeoY axis and a Projection CoordinateTransform will have isGeoReferencing() true. A CoordinateSystem that has a Height, Pressure, or GeoZ axis will have hasVerticalAxis() true.

Further CoordinateSystems specialization is done by "data type specific" classes such as ucar.nc2.ft2.coverage.grid.GridCoordSys.

See Also:

  • Method Details

    • makeName

      public static String makeName(List<CoordinateAxis> axes)
      Create standard name from list of axes. Sort the axes first
      Parameters:
      axes - list of CoordinateAxis
      Returns:
      CoordinateSystem name, created from axes names

    • getCoordinateAxes

      public com.google.common.collect.ImmutableList<CoordinateAxis> getCoordinateAxes()
      Get the List of CoordinateAxis objects

    • getCoordinateTransforms

      public com.google.common.collect.ImmutableList<CoordinateTransform> getCoordinateTransforms()
      Get the List of CoordinateTransform objects

    • getName

      public String getName()
      get the name of the Coordinate System
      Returns:
      the name of the Coordinate System

    • getNetcdfDataset

      public NetcdfDataset getNetcdfDataset()
      Get the underlying NetcdfDataset
      Returns:
      the underlying NetcdfDataset.

    • getDomain

      public com.google.common.collect.ImmutableCollection<Dimension> getDomain()
      get the Collection of Dimensions that constitute the domain.

    • getRankDomain

      public int getRankDomain()
      Get the domain rank of the coordinate system = number of dimensions it is a function of.
      Returns:
      domain.size()

    • getRankRange

      public int getRankRange()
      Get the range rank of the coordinate system = number of coordinate axes.
      Returns:
      coordAxes.size()

    • findAxis

      public CoordinateAxis findAxis(AxisType type)
      Find the CoordinateAxis that has the given AxisType. If more than one, return the one with lesser rank.
      Parameters:
      type - look for this axisType
      Returns:
      CoordinateAxis of the given AxisType, else null.

    • getXaxis

      public CoordinateAxis getXaxis()
      get the CoordinateAxis with AxisType.GeoX, or null if none. if more than one, choose one with smallest rank
      Returns:
      axis of type AxisType.GeoX, or null if none

    • getYaxis

      public CoordinateAxis getYaxis()
      get the CoordinateAxis with AxisType.GeoY, or null if none. if more than one, choose one with smallest rank
      Returns:
      axis of type AxisType.GeoY, or null if none

    • getZaxis

      public CoordinateAxis getZaxis()
      get the CoordinateAxis with AxisType.GeoZ, or null if none. if more than one, choose one with smallest rank
      Returns:
      axis of type AxisType.GeoZ, or null if none

    • getTaxis

      public CoordinateAxis getTaxis()
      get the CoordinateAxis with AxisType.Time, or null if none. if more than one, choose one with smallest rank
      Returns:
      axis of type AxisType.Time, or null if none

    • getLatAxis

      public CoordinateAxis getLatAxis()
      get the CoordinateAxis with AxisType.Lat, or null if none. if more than one, choose one with smallest rank
      Returns:
      axis of type AxisType.Lat, or null if none

    • getLonAxis

      public CoordinateAxis getLonAxis()
      get the CoordinateAxis with AxisType.Lon, or null if none. if more than one, choose one with smallest rank *
      Returns:
      axis of type AxisType.Lon, or null if none

    • getHeightAxis

      public CoordinateAxis getHeightAxis()
      get the CoordinateAxis with AxisType.Height, or null if none. if more than one, choose one with smallest rank
      Returns:
      axis of type AxisType.Height, or null if none

    • getPressureAxis

      public CoordinateAxis getPressureAxis()
      get the CoordinateAxis with AxisType.Pressure, or null if none. if more than one, choose one with smallest rank.
      Returns:
      axis of type AxisType.Pressure, or null if none

    • getEnsembleAxis

      public CoordinateAxis getEnsembleAxis()
      get the CoordinateAxis with AxisType.Ensemble, or null if none. if more than one, choose one with smallest rank.
      Returns:
      axis of type AxisType.Ensemble, or null if none

    • getAzimuthAxis

      public CoordinateAxis getAzimuthAxis()
      get the CoordinateAxis with AxisType.RadialAzimuth, or null if none. if more than one, choose one with smallest rank
      Returns:
      axis of type AxisType.RadialAzimuth, or null if none

    • getRadialAxis

      public CoordinateAxis getRadialAxis()
      get the CoordinateAxis with AxisType.RadialDistance, or null if none. if more than one, choose one with smallest rank
      Returns:
      axis of type AxisType.RadialDistance, or null if none

    • getElevationAxis

      public CoordinateAxis getElevationAxis()
      get the CoordinateAxis with AxisType.RadialElevation, or null if none. if more than one, choose one with smallest rank
      Returns:
      axis of type AxisType.RadialElevation, or null if none

    • getProjectionCT

      public ProjectionCT getProjectionCT()
      Find the first ProjectionCT from the list of CoordinateTransforms.
      Returns:
      ProjectionCT or null if none.

    • getProjection

      public ucar.unidata.geoloc.ProjectionImpl getProjection()
      Get the Projection for this coordinate system. If isLatLon(), then returns a LatLonProjection. Otherwise, extracts the projection from any ProjectionCT CoordinateTransform.
      Returns:
      ProjectionImpl or null if none. TODO return Projection in ver6

    • isGeoXY

      public boolean isGeoXY()
      true if it has X and Y CoordinateAxis, and a CoordTransform Projection
      Returns:
      true if it has X and Y CoordinateAxis, and a CoordTransform Projection

    • isLatLon

      public boolean isLatLon()
      true if it has Lat and Lon CoordinateAxis
      Returns:
      true if it has Lat and Lon CoordinateAxis

    • isRadial

      public boolean isRadial()
      true if it has radial distance and azimuth CoordinateAxis
      Returns:
      true if it has radial distance and azimuth CoordinateAxis

    • isGeoReferencing

      public boolean isGeoReferencing()
      true if isGeoXY or isLatLon
      Returns:
      true if isGeoXY or isLatLon

    • isProductSet

      public boolean isProductSet()
      true if all axes are CoordinateAxis1D
      Returns:
      true if all axes are CoordinateAxis1D

    • isRegular

      public boolean isRegular()
      true if all axes are CoordinateAxis1D and are regular
      Returns:
      true if all axes are CoordinateAxis1D and are regular

    • isComplete

      public boolean isComplete(Variable v)
      Check if this Coordinate System is complete for v, ie if all its dimensions are also used by v.
      Parameters:
      v - check for this variable
      Returns:
      true if all dimensions in V (including parents) are in the domain of this coordinate system.

    • isCoordinateSystemFor

      public boolean isCoordinateSystemFor(Variable v)
      Check if this Coordinate System can be used for the given variable. A CoordinateAxis can only be part of a Variable's CoordinateSystem if the CoordinateAxis' set of Dimensions is a subset of the Variable's set of Dimensions. So, a CoordinateSystem' set of Dimensions must be a subset of the Variable's set of Dimensions.
      Parameters:
      v - check for this variable
      Returns:
      true if all dimensions in the domain of this coordinate system are in V (including parents).

    • isSubset

      public static boolean isSubset(Collection<Dimension> subset, Collection<Dimension> set)
      Test if all the Dimensions in subset are in set
      Parameters:
      subset - is this a subset
      set - of this?
      Returns:
      true if all the Dimensions in subset are in set

    • isSubset

      public static boolean isSubset(Set<String> subset, Set<String> set)

    • makeDomain

      public static Set<Dimension> makeDomain(Iterable<? extends Variable> axes)

    • countDomain

      public static int countDomain(Variable[] axes)

    • isImplicit

      public boolean isImplicit()
      Implicit Coordinate System are constructed based on which Coordinate Variables exist for the Dimensions of the Variable. This is in contrast to a Coordinate System that is explicitly specified in the file.
      Returns:
      true if this coordinate system was constructed implicitly.

    • hasVerticalAxis

      public boolean hasVerticalAxis()
      true if has Height, Pressure, or GeoZ axis
      Returns:
      true if has a vertical axis

    • hasTimeAxis

      public boolean hasTimeAxis()
      true if has Time axis
      Returns:
      true if has Time axis

    • containsAxes

      public boolean containsAxes(List<CoordinateAxis> wantAxes)
      Do we have all the axes in the list?
      Parameters:
      wantAxes - List of CoordinateAxis
      Returns:
      true if all in our list.

    • containsAxis

      public boolean containsAxis(String axisName)
      Do we have the named axis?
      Parameters:
      axisName - (full unescaped) name of axis
      Returns:
      true if we have an axis of that name

    • containsDomain

      public boolean containsDomain(List<Dimension> wantDimensions)
      Do we have all the dimensions in the list?
      Parameters:
      wantDimensions - List of Dimensions
      Returns:
      true if all in our list.

    • containsAxisTypes

      public boolean containsAxisTypes(List<AxisType> wantAxes)
      Do we have all the axes types in the list?
      Parameters:
      wantAxes - List of AxisType
      Returns:
      true if all in our list.

    • containsAxisType

      public boolean containsAxisType(AxisType wantAxisType)
      Do we have an axes of the given type?
      Parameters:
      wantAxisType - want this AxisType
      Returns:
      true if we have at least one axis of that type.

    • equals

      public boolean equals(Object oo)
      Instances which have same name, axes and transforms are equal.
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Override Object.hashCode() to implement equals.
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • toBuilder

      public CoordinateSystem.Builder<?> toBuilder()

    • builder

      public static CoordinateSystem.Builder<?> builder()
      Get Builder for this class that allows subclassing.
      See Also:
      • "https://community.oracle.com/blogs/emcmanus/2010/10/24/using-builder-pattern-subclasses"