ucar.nc2.dataset

Class CoordinateAxis

java.lang.Object

ucar.nc2.CDMNode

ucar.nc2.Variable

ucar.nc2.dataset.VariableDS

ucar.nc2.dataset.CoordinateAxis

All Implemented Interfaces:

java.lang.Comparable<VariableSimpleIF>, IsMissingEvaluator, AttributeContainer, Enhancements, EnhanceScaleMissing, VariableEnhanced, ProxyReader, VariableIF, 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.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CoordinateAxis.AxisComparator Standard sort on Coordinate Axes

Nested classes/interfaces inherited from class ucar.nc2.Variable

Variable.Cache

Field Summary

Fields

Modifier and Type	Field and Description
static int	axisSizeToCache
protected AxisType	axisType
protected java.lang.String	boundaryRef
protected boolean	isContiguous
protected NetcdfDataset	ncd
protected java.lang.String	positive

Fields inherited from class ucar.nc2.dataset.VariableDS

orgDataType, orgName, orgVar

Fields inherited from class ucar.nc2.Variable

attributes, cache, dataType, debugCaching, defaultCoordsSizeToCache, defaultSizeToCache, dimensions, elementSize, hashCode, isMetadata, isVariableLength, ncfile, permitCaching, proxyReader, shape, shapeAsSection, sizeToCache, spiObject

Fields inherited from class ucar.nc2.CDMNode

annotations, dodsname, group, immutable, parentstruct, shortName, sort

Constructor Summary

Constructors

Modifier	Constructor and Description
	CoordinateAxis(NetcdfDataset ds, Group group, java.lang.String shortName, DataType dataType, java.lang.String dims, java.lang.String units, java.lang.String desc) Constructor when theres no underlying variable.
protected	CoordinateAxis(NetcdfDataset ncd, VariableDS vds) Create a coordinate axis from an existing Variable.

Method Summary

Modifier and Type	Method and Description
protected Variable	copy()
CoordinateAxis	copyNoCache() Make a copy, with an independent cache.
boolean	equals(java.lang.Object oo) Instances which have same content are equal.
static CoordinateAxis	factory(NetcdfDataset ncd, VariableDS vds) Create a coordinate axis from an existing Variable.
AxisType	getAxisType() Get type of axis
java.lang.String	getBoundaryRef() The name of this coordinate axis' boundary variable
protected Calendar	getCalendarFromAttribute()
void	getInfo(java.util.Formatter buf) Get a string representation
double	getMaxValue() The largest coordinate value.
double	getMinValue() The smallest coordinate value.
java.lang.String	getPositive() Get the direction of increasing values, used only for vertical Axes.
java.lang.String	getUnitsString() Get the Unit String for the Variable.
int	hashCode() Override Object.hashCode() to implement equals.
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.
boolean	isCoordinateVariable() Calculate if this is a classic coordinate variable: has same name as its first dimension.
boolean	isInterval() An interval coordinate consists of two numbers, bound1 and bound2.
boolean	isNumeric() Does the axis have numeric values.
void	setAxisType(AxisType axisType) Set type of axis, or null if none.
void	setBoundaryRef(java.lang.String boundaryRef) Set a reference to a boundary variable.
void	setPositive(java.lang.String positive) Set the direction of increasing values, used only for vertical Axes.

Methods inherited from class ucar.nc2.dataset.VariableDS

_read, _read, addCoordinateSystem, clearCoordinateSystems, convertEnums, convertScaleOffsetMissing, convertScaleOffsetMissing, convertScaleOffsetMissing, convertScaleOffsetMissing, convertScaleOffsetMissing, convertScaleOffsetMissing, enhance, getCoordinateSystems, getDatasetLocation, getDescription, getEnhanceMode, getMissingDataArray, getOriginalDataType, getOriginalName, getOriginalVariable, getUseNaNs, getValidMax, getValidMin, hasCachedDataRecurse, hasFillValue, hasInvalidData, hasMissing, hasMissingValue, hasScaleOffset, isFillValue, isInvalidData, isMissing, isMissingFast, isMissingValue, lookupEnumString, readToStream, reallyRead, reallyRead, removeCoordinateSystem, setCaching, setFillValueIsMissing, setInvalidDataIsMissing, setMissingDataIsMissing, setName, setOriginalVariable, setUnitsString, setUseNaNs, showScaleMissingProxy, toStringDebug

Methods inherited from class ucar.nc2.Variable

addAll, addAttribute, compareTo, createNewCache, extraInfo, findAttribute, findAttributeIgnoreCase, findDimensionIndex, getAttributes, getDAPName, getDAPName, getDataType, getDimension, getDimensions, getDimensionsAll, getDimensionsString, getElementSize, getEnumTypedef, getNameAndDimensions, getNameAndDimensions, getNameAndDimensions, getNameAndDimensions, getNameAndDimensions, getNameAndDimensions, getNetcdfFile, getParentGroup, getProxyReader, getRanges, getRank, getScalarData, getShape, getShape, getShapeAll, getShapeAsSection, getShapeNotScalar, getSize, getSizeToCache, getSPobject, hasCachedData, hashCodeShow, invalidateCache, isCaching, isImmutable, isMetadata, isScalar, isUnknownLength, isUnlimited, isUnsigned, isVariableLength, read, read, read, read, read, readScalarByte, readScalarDouble, readScalarFloat, readScalarInt, readScalarLong, readScalarShort, readScalarString, readToByteChannel, reduce, remove, removeAttribute, removeAttributeIgnoreCase, resetDimensions, resetShape, section, section, setCachedData, setCachedData, setDataType, setDimension, setDimensions, setDimensions, setDimensionsAnonymous, setElementSize, setEnumTypedef, setImmutable, setIsScalar, setParentGroup, setProxyReader, setSizeToCache, setSPobject, setUnsigned, setValues, setValues, slice, toString, writeCDL, writeCDL

Methods inherited from class ucar.nc2.CDMNode

annotate, getAnnotation, getAnnotations, getDODSName, getFullName, getFullNameEscaped, getGroup, getImmutable, getName, getParentStructure, getShortName, getSort, isMemberOfStructure, localhash, setDODSName, setImmutable, setParentStructure, setShortName, setSort, unwrap

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface ucar.nc2.VariableIF

findAttribute, findAttributeIgnoreCase, findDimensionIndex, getAttributes, getDataType, getDimension, getDimensions, getDimensionsAll, getElementSize, getEnumTypedef, getFullName, getFullNameEscaped, getNameAndDimensions, getParentGroup, getParentStructure, getRanges, getRank, getShape, getShapeAsSection, getShortName, getSize, isMemberOfStructure, isMetadata, isScalar, isUnlimited, isUnsigned, isVariableLength, read, read, read, read, readScalarByte, readScalarDouble, readScalarFloat, readScalarInt, readScalarLong, readScalarShort, readScalarString, section

Methods inherited from interface ucar.nc2.VariableSimpleIF

getName

Methods inherited from interface java.lang.Comparable

compareTo

Field Detail

axisSizeToCache

public static int axisSizeToCache

ncd

protected NetcdfDataset ncd

axisType

protected AxisType axisType

positive

protected java.lang.String positive

boundaryRef

protected java.lang.String boundaryRef

isContiguous

protected boolean isContiguous

Constructor Detail

CoordinateAxis

protected CoordinateAxis(NetcdfDataset ncd,
                         VariableDS vds)

Create a coordinate axis from an existing Variable. General case.

Parameters:

ncd - the containing dataset

vds - an existing Variable

CoordinateAxis

public CoordinateAxis(NetcdfDataset ds,
                      Group group,
                      java.lang.String shortName,
                      DataType dataType,
                      java.lang.String dims,
                      java.lang.String units,
                      java.lang.String desc)

Constructor when theres no underlying variable. You better set the values too!

Parameters:

ds - the containing dataset.

group - the containing group; if null, use rootGroup

shortName - axis name.

dataType - data type

dims - list of dimension names

units - units of coordinates, preferably udunit compatible.

desc - long name.

Method Detail

factory

public static CoordinateAxis factory(NetcdfDataset ncd,
                                     VariableDS vds)

Create a coordinate axis from an existing Variable.

Parameters:

ncd - the containing dataset

vds - 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

copy

protected Variable copy()

Overrides:

copy in class VariableDS

getAxisType

public AxisType getAxisType()

Get type of axis

Returns:

type of axis, or null if none.

setAxisType

public void setAxisType(AxisType axisType)

Set type of axis, or null if none. Default is none.

Parameters:

axisType - set to this value

getUnitsString

public java.lang.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 Enhancements

Specified by:

getUnitsString in interface VariableIF

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.

getPositive

public java.lang.String getPositive()

Get the direction of increasing values, used only for vertical Axes.

Returns:

POSITIVE_UP, POSITIVE_DOWN, or null if unknown.

setPositive

public void setPositive(java.lang.String positive)

Set the direction of increasing values, used only for vertical Axes.

Parameters:

positive - POSITIVE_UP, POSITIVE_DOWN, or null if you dont know..

getBoundaryRef

public java.lang.String getBoundaryRef()

The name of this coordinate axis' boundary variable

Returns:

the name of this coordinate axis' boundary variable, or null if none.

setBoundaryRef

public void setBoundaryRef(java.lang.String boundaryRef)

Set a reference to a boundary variable.

Parameters:

boundaryRef - the name of a boundary coordinate variable in the same dataset.

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(java.util.Formatter buf)

Get a string representation

Parameters:

buf - place info here

equals

public boolean equals(java.lang.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

protected Calendar getCalendarFromAttribute()

isCoordinateVariable

public boolean isCoordinateVariable()

Description copied from class: Variable

Calculate if this is a classic coordinate variable: has same name as its first dimension. If type char, must be 2D, else must be 1D.

Specified by:

isCoordinateVariable in interface VariableIF

Overrides:

isCoordinateVariable in class Variable

Returns:

true if a coordinate variable.