Package ucar.nc2.dataset

Class CoordinateAxis

  • All Implemented Interfaces:
    Comparable<VariableSimpleIF>, Iterable<Attribute>, IsMissingEvaluator, AttributeContainer, ucar.nc2.dataset.Enhancements, ucar.nc2.dataset.EnhanceScaleMissingUnsigned, VariableEnhanced, ProxyReader, VariableSimpleIF
    Direct Known Subclasses:
    CoordinateAxis1D, CoordinateAxis2D
    public class CoordinateAxis
extends VariableDS
    A Coordinate Axis is a Variable that specifies one of the coordinates of a CoordinateSystem. Mathematically it is a scalar function F from index space to S: 
      F:D -> S
  where D is a product set of dimensions (aka index space), and S is the set of reals (R) or Strings.

    If its element type is char, it is considered a string-valued Coordinate Axis and rank is reduced by one, since the outermost dimension is considered the string length: v(i, j, .., strlen). If its element type is String, it is a string-valued Coordinate Axis. Otherwise it is numeric-valued, and isNumeric() is true.

    The one-dimensional case F(i) -> R is the common case which affords important optimizations. In that case, use the subtype CoordinateAxis1D. The factory methods will return either a CoordinateAxis1D if the variable is one-dimensional, a CoordinateAxis2D if its 2D, or a CoordinateAxis for the general case.

    A CoordinateAxis is optionally marked as georeferencing with an AxisType. It should have a units string and optionally a description string.

    A Structure cannot be a CoordinateAxis, although members of Structures can.

    • Method Detail

      • fromVariableDS

        public static CoordinateAxis.Builder fromVariableDS​(VariableDS.Builder<?> vdsBuilder)
        Create a coordinate axis from an existing Variable.Builder.
        Parameters:
        vdsBuilder - an existing Variable in dataset.
        Returns:
        CoordinateAxis or one of its subclasses (CoordinateAxis1D, CoordinateAxis2D, or CoordinateAxis1DTime).

      • copyNoCache

        public CoordinateAxis copyNoCache()
        Make a copy, with an independent cache.
        Returns:
        copy of this CoordinateAxis

      • getAxisType

        public AxisType getAxisType()
        Get type of axis
        Returns:
        type of axis, or null if none.

      • getUnitsString

        public String getUnitsString()
        Description copied from class: Variable
        Get the Unit String for the Variable. Looks for the CDM.UNITS attribute value
        Specified by:
        getUnitsString in interface ucar.nc2.dataset.Enhancements
        Specified by:
        getUnitsString in interface VariableSimpleIF
        Overrides:
        getUnitsString in class VariableDS
        Returns:
        unit string, or null if not found.

      • isNumeric

        public boolean isNumeric()
        Does the axis have numeric values.
        Returns:
        true if the CoordAxis is numeric, false if its string valued ("nominal").

      • isContiguous

        public boolean isContiguous()
        If the edges are contiguous or disjoint Caution: many datasets do not explicitly specify this info, this is often a guess; default is true.
        Returns:
        true if the edges are contiguous or false if disjoint. Assumed true unless set otherwise.

      • isInterval

        public boolean isInterval()
        An interval coordinate consists of two numbers, bound1 and bound2. The coordinate value must lie between them, but otherwise is somewhat arbitrary. If not interval, then it has one number, the coordinate value.
        Returns:
        true if its an interval coordinate.

      • isIndependentCoordinate

        public boolean isIndependentCoordinate()

      • getPositive

        public String getPositive()
        Get the direction of increasing values, used only for vertical Axes.
        Returns:
        POSITIVE_UP, POSITIVE_DOWN, or null if unknown.

      • getBoundaryRef

        public String getBoundaryRef()
        The name of this coordinate axis' boundary variable
        Returns:
        the name of this coordinate axis' boundary variable, or null if none.

      • getMinValue

        public double getMinValue()
        The smallest coordinate value. Only call if isNumeric.
        Returns:
        the minimum coordinate value

      • getMaxValue

        public double getMaxValue()
        The largest coordinate value. Only call if isNumeric.
        Returns:
        the maximum coordinate value

      • getInfo

        public void getInfo​(Formatter buf)
        Get a string representation
        Parameters:
        buf - place info here

      • equals

        public boolean equals​(Object oo)
        Instances which have same content are equal.
        Overrides:
        equals in class Variable

      • hashCode

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

      • getCalendarFromAttribute

        public Calendar getCalendarFromAttribute()

      • builder

        public static CoordinateAxis.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"