All Implemented Interfaces:

Comparable<Variable>, ProxyReader

Direct Known Subclasses:

Structure, VariableDS
```
@Immutable
public class Variable
extends Object
implements ProxyReader, Comparable<Variable>
```
A logical container for data, with a dataType, a set of Dimensions that define its array shape, and a set of Attributes.
The data is a multidimensional array of primitive types, Strings, or Structures. Data access is done through the readXXX() methods, which return a memory resident Array.
The cache isnt immutable, but changes to it should not be visible.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class Variable.Builder<T extends Variable.Builder<T>>

Field Summary

Fields
Modifier and Type Field Description

static boolean permitCaching
Globally permit or prohibit caching.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`AttributeContainer`	`attributes()`	The attributes contained by this Variable.
`static Variable.Builder<?>`	`builder()`	Get Builder for this class that allows subclassing.
`int`	`compareTo(Variable o)`	Sort by name
`boolean`	`equals(Object oo)`
`Attribute`	`findAttribute(String name)`	Find the attribute by name, return null if not exist
`String`	`findAttributeString(String attName, String defaultValue)`	Find a String-valued Attribute by name (ignore case), return the String value of the Attribute.
`int`	`findDimensionIndex(String name)`	Find the index of the named Dimension in this Variable.
`ArrayType`	`getArrayType()`	Get the data type of the Variable.
`String`	`getDatasetLocation()`	The location of the dataset this belongs to.
`String`	`getDescription()`	Get the description of the Variable.
`Dimension`	`getDimension(int i)`	Get the ith dimension.
`List<Dimension>`	`getDimensions()`	Get the list of dimensions used by this variable.
`Set<Dimension>`	`getDimensionSet()`	Get the variable's Dimensions as a Set.
`String`	`getDimensionsString()`	Get the list of Dimension names, space delineated.
`int`	`getElementSize()`	Get the number of bytes for one element of this Variable.
`EnumTypedef`	`getEnumTypedef()`	Get the EnumTypedef, only use if getDataType.isEnum()
`String`	`getFileTypeId()`	Get the file type id for the underlying data source.
`String`	`getFullName()`	Get the full name of this Variable.
`String`	`getNameAndDimensions()`	Get the display name plus the dimensions, eg 'float name(dim1, dim2)'
`void`	`getNameAndDimensions(Formatter buf, boolean useFullName, boolean strict)`	Add display name plus the dimensions to the Formatter
`NetcdfFile`	`getNetcdfFile()`	Get the NetcdfFile that this variable is contained in.
`Group`	`getParentGroup()`	Get its containing Group, never null
`Structure`	`getParentStructure()`	Get its parent structure, or null if not in structure
`int`	`getRank()`	Get the number of dimensions of the Variable, aka the rank.
`Section`	`getSection()`	Get shape as a Section object.
`int[]`	`getShape()`	Get the shape: length of Variable in each dimension.
`int`	`getShape(int index)`	Get the size of the ith dimension
`String`	`getShortName()`	The short name of the variable
`long`	`getSize()`	Get the total number of elements in the Variable.
`int`	`getSizeToCache()`	If total data size is less than SizeToCache in bytes, then cache.
`Object`	`getSPobject()`	Get immutable service provider opaque object.
`String`	`getUnitsString()`	Get the Unit String for the Variable.
`boolean`	`hasCachedData()`	If this has cached data, or source data.
`int`	`hashCode()`
`boolean`	`isCaching()`	Will this Variable be cached when read.
`boolean`	`isCoordinateVariable()`	Calculate if this is a classic coordinate variable: has same name as its first dimension.
`boolean`	`isMemberOfStructure()`	Is this a Structure Member?
`boolean`	`isMetadata()`	Is this variable metadata?.
`boolean`	`isScalar()`	Whether this is a scalar Variable (rank == 0).
`boolean`	`isUnlimited()`	Can this variable's size grow?.
`boolean`	`isVariableLength()`	Does this variable have a variable length dimension? If so, it has as one of its dimensions Dimension.VLEN.
`String`	`lookupEnumString(int val)`	Lookup the enum string for this value.
`Array<?>`	`proxyReadArray(Variable client, Section section, CancelTask cancelTask)`	public by accident, do not call directly.
`Array<?>`	`proxyReadArray(Variable client, CancelTask cancelTask)`	public by accident, do not call directly.
`Array<?>`	`readArray()`	Read all the data for this Variable and return a memory resident Array.
`Array<?>`	`readArray(Section section)`	Read a section of the data for this Variable from the netcdf file and return a memory resident Array.
`byte`	`readScalarByte()`	Get the first value as a byte.
`double`	`readScalarDouble()`	Get the first value as a double.
`float`	`readScalarFloat()`	Get the first value as a float.
`int`	`readScalarInt()`	Get the first value as an int.
`long`	`readScalarLong()`	Get the first value as a long.
`short`	`readScalarShort()`	Get the first value as a short.
`String`	`readScalarString()`	Get the first value as a String for a STRING or CHAR Variable.
`Variable`	`reduce(List<Dimension> dims)`	Create a new Variable that is a logical view of this Variable, by eliminating the specified dimension(s) of length 1.
`Variable`	`section(Section subsection)`	Create a new Variable that is a logical subsection of this Variable.
`void`	`setCaching(boolean caching)`	Set whether to cache or not.
`Variable`	`slice(int dim, int value)`	Create a new Variable that is a logical slice of this Variable, by fixing the specified dimension at the specified index value.
`Variable.Builder<?>`	`toBuilder()`	Turn into a mutable Builder.
`String`	`toString()`

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - permitCaching
```
public static boolean permitCaching
```
    Globally permit or prohibit caching. For use during testing and debugging.
    A true value for this field does not indicate whether a Variable is caching, only that it's permitted to cache.
- Method Detail
  - findDimensionIndex
```
public int findDimensionIndex(String name)
```
    Find the index of the named Dimension in this Variable.
    
    Parameters:
    
    name - the name of the dimension
    
    Returns:
    
    the index of the named Dimension, or -1 if not found.
  - getDatasetLocation
```
public String getDatasetLocation()
```
    The location of the dataset this belongs to. Labeling purposes only.
  - getArrayType
```
public ArrayType getArrayType()
```
    Get the data type of the Variable.
  - getDescription
```
public String getDescription()
```
    Get the description of the Variable. Default is to use CDM.LONG_NAME attribute value. If not exist, look for "description", "title", or "standard_name" attribute value (in that order).
    
    Returns:
    
    description, or null if not found.
  - getDimensions
```
public List<Dimension> getDimensions()
```
    Get the list of dimensions used by this variable. The most slowly varying (leftmost for Java and C programmers) dimension is first. For scalar variables, the list is empty.
  - getDimensionSet
```
public Set<Dimension> getDimensionSet()
```
    Get the variable's Dimensions as a Set.
  - getDimension
```
public Dimension getDimension(int i)
```
    Get the ith dimension.
    
    Parameters:
    
    i - index of the dimension.
    
    Returns:
    
    requested Dimension, or null if i is out of bounds.
  - getDimensionsString
```
public String getDimensionsString()
```
    Get the list of Dimension names, space delineated.
  - getElementSize
```
public int getElementSize()
```
    Get the number of bytes for one element of this Variable. For Variables of primitive type, this is equal to getArrayType().getSize(). Structure and subclasses return the size in bytes of one Structure. This is the canonical size, not the actual size stored on disk.
  - getEnumTypedef
```
@Nullable
public EnumTypedef getEnumTypedef()
```
    Get the EnumTypedef, only use if getDataType.isEnum()
  - getFileTypeId
```
@Nullable
public String getFileTypeId()
```
    Get the file type id for the underlying data source.
    
    Returns:
    
    registered id of the file type
    
    See Also:
    
    "https://www.unidata.ucar.edu/software/netcdf-java/formats/FileTypes.html"
  - getFullName
```
public String getFullName()
```
    Get the full name of this Variable. see NetcdfFiles.makeFullName(Variable)
  - getNetcdfFile
```
@Nullable
public NetcdfFile getNetcdfFile()
```
    Get the NetcdfFile that this variable is contained in. May be null when the Variable is self contained.
  - getParentGroup
```
public Group getParentGroup()
```
    Get its containing Group, never null
  - getParentStructure
```
@Nullable
public Structure getParentStructure()
```
    Get its parent structure, or null if not in structure
  - getRank
```
public int getRank()
```
    Get the number of dimensions of the Variable, aka the rank.
  - getShape
```
public int[] getShape()
```
    Get the shape: length of Variable in each dimension. A scalar (rank 0) will have an int[0] shape.
  - getShape
```
public int getShape(int index)
```
    Get the size of the ith dimension
  - getSection
```
public Section getSection()
```
    Get shape as a Section object.
    
    Returns:
    
    Section describing this Variable's shape.
  - getShortName
```
public String getShortName()
```
    The short name of the variable
  - getSize
```
public long getSize()
```
    Get the total number of elements in the Variable. If this is an unlimited Variable, will use the current number of elements. If this is a Sequence, will return 1. If variable length, will skip vlen dimensions
    
    Returns:
    
    total number of elements in the Variable.
  - getUnitsString
```
@Nullable
public String getUnitsString()
```
    Get the Unit String for the Variable. Looks for the CDM.UNITS attribute value
    
    Returns:
    
    unit string, or null if not found.
  - isCoordinateVariable
```
public boolean isCoordinateVariable()
```
    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.
    
    Returns:
    
    true if a coordinate variable.
  - isMemberOfStructure
```
public boolean isMemberOfStructure()
```
    Is this a Structure Member?
  - isMetadata
```
public boolean isMetadata()
```
    Is this variable metadata?. True if its values need to be included explicitly in NcML output.
  - isScalar
```
public boolean isScalar()
```
    Whether this is a scalar Variable (rank == 0).
  - isUnlimited
```
public boolean isUnlimited()
```
    Can this variable's size grow?. This is equivalent to saying at least one of its dimensions is unlimited.
    
    Returns:
    
    boolean true iff this variable can grow
  - isVariableLength
```
public boolean isVariableLength()
```
    Does this variable have a variable length dimension? If so, it has as one of its dimensions Dimension.VLEN.
    
    Returns:
    
    true if Variable has a variable length dimension?
  - lookupEnumString
```
@Nullable
public String lookupEnumString(int val)
```
    Lookup the enum string for this value. Can only be called on enum types, where dataType.isEnum() is true.
    
    Parameters:
    
    val - the integer value of this enum
    
    Returns:
    
    the String value, or null if not exist.
  - section
```
public Variable section(Section subsection)
                 throws InvalidRangeException
```
    Create a new Variable that is a logical subsection of this Variable. No data is read until a read method is called on it.
    
    Parameters:
    
    subsection - Section of this variable. Each Range in the section corresponds to a Dimension, and specifies the section of data to read in that Dimension. A Range object may be null, which means use the entire dimension.
    
    Returns:
    
    a new Variable which is a logical section of this Variable.
    
    Throws:
    
    InvalidRangeException - if section not compatible with shape
  - slice
```
public Variable slice(int dim,
                      int value)
               throws InvalidRangeException
```
    Create a new Variable that is a logical slice of this Variable, by fixing the specified dimension at the specified index value. This reduces rank by 1. No data is read until a read method is called on it.
    
    Parameters:
    
    dim - which dimension to fix
    
    value - at what index value
    
    Returns:
    
    a new Variable which is a logical slice of this Variable.
    
    Throws:
    
    InvalidRangeException - if dimension or value is illegal
  - reduce
```
public Variable reduce(List<Dimension> dims)
```
    Create a new Variable that is a logical view of this Variable, by eliminating the specified dimension(s) of length 1. No data is read until a read method is called on it.
    
    Parameters:
    
    dims - list of dimensions of length 1 to reduce
    
    Returns:
    
    a new Variable which is a logical slice of this Variable.
  - readScalarByte
```
public byte readScalarByte()
                    throws IOException
```
    Get the first value as a byte.
    
    Throws:
    
    IOException - if theres an IO Error
    
    RuntimeException - if data type not convertible to byte
  - readScalarShort
```
public short readScalarShort()
                      throws IOException
```
    Get the first value as a short.
    
    Throws:
    
    IOException - if theres an IO Error
    
    RuntimeException - if data type not convertible to short
  - readScalarInt
```
public int readScalarInt()
                  throws IOException
```
    Get the first value as an int.
    
    Throws:
    
    IOException - if theres an IO Error
    
    RuntimeException - if data type not convertible to int
  - readScalarLong
```
public long readScalarLong()
                    throws IOException
```
    Get the first value as a long.
    
    Throws:
    
    IOException - if theres an IO Error
    
    RuntimeException - if data type not convertible to long
  - readScalarFloat
```
public float readScalarFloat()
                      throws IOException
```
    Get the first value as a float.
    
    Throws:
    
    IOException - if theres an IO Error
    
    RuntimeException - if data type not convertible to float
  - readScalarDouble
```
public double readScalarDouble()
                        throws IOException
```
    Get the first value as a double.
    
    Throws:
    
    IOException - if theres an IO Error
    
    RuntimeException - if data type not convertible to double
  - readScalarString
```
public String readScalarString()
                        throws IOException
```
    Get the first value as a String for a STRING or CHAR Variable.
    
    Throws:
    
    IOException - if theres an IO Error
    
    IllegalArgumentException - if data type not STRING or CHAR
  - readArray
```
public Array<?> readArray()
                   throws IOException
```
    Read all the data for this Variable and return a memory resident Array. The Array has the same element type and shape as the Variable.
    
    Throws:
    
    IOException
  - readArray
```
public Array<?> readArray(@Nullable
                          Section section)
                   throws IOException,
                          InvalidRangeException
```
    Read a section of the data for this Variable from the netcdf file and return a memory resident Array. The Array has the same element type as the Variable, and the requested shape. Note that this does not do rank reduction, so the returned Array has the same rank as the Variable. Use Array.reduce() for rank reduction.
    
    Parameters:
    
    section - The section of data to read. Must be null or same rank as variable. If list is null, assume all data. Each Range corresponds to a Dimension. If the Range object is null, it means use the entire dimension.
    
    Throws:
    
    IOException
    
    InvalidRangeException
  - proxyReadArray
```
public Array<?> proxyReadArray(Variable client,
                               CancelTask cancelTask)
                        throws IOException
```
    public by accident, do not call directly.
    
    Specified by:
    
    proxyReadArray in interface ProxyReader
    
    Throws:
    
    IOException
  - proxyReadArray
```
public Array<?> proxyReadArray(Variable client,
                               Section section,
                               CancelTask cancelTask)
                        throws IOException,
                               InvalidRangeException
```
    public by accident, do not call directly.
    
    Specified by:
    
    proxyReadArray in interface ProxyReader
    
    Throws:
    
    IOException
    
    InvalidRangeException
  - getNameAndDimensions
```
public String getNameAndDimensions()
```
    Get the display name plus the dimensions, eg 'float name(dim1, dim2)'
  - getNameAndDimensions
```
public void getNameAndDimensions(Formatter buf,
                                 boolean useFullName,
                                 boolean strict)
```
    Add display name plus the dimensions to the Formatter
    
    Parameters:
    
    buf - add info to this
    
    useFullName - use full name else short name. strict = true implies short name
    
    strict - strictly comply with ncgen syntax, with name escaping. otherwise, get extra info, no escaping
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - equals
```
public boolean equals(Object oo)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - compareTo
```
public int compareTo(Variable o)
```
    Sort by name
    
    Specified by:
    
    compareTo in interface Comparable<Variable>
  - attributes
```
public AttributeContainer attributes()
```
    The attributes contained by this Variable.
  - findAttribute
```
@Nullable
public Attribute findAttribute(String name)
```
    Find the attribute by name, return null if not exist
  - findAttributeString
```
public String findAttributeString(String attName,
                                  String defaultValue)
```
    Find a String-valued Attribute by name (ignore case), return the String value of the Attribute.
    
    Returns:
    
    the attribute value, or defaultValue if not found
  - getSPobject
```
public Object getSPobject()
```
    Get immutable service provider opaque object.
  - getSizeToCache
```
public int getSizeToCache()
```
    If total data size is less than SizeToCache in bytes, then cache.
    
    Returns:
    
    size at which caching happens
  - setCaching
```
public void setCaching(boolean caching)
```
    Set whether to cache or not. Implies that the entire array will be stored, once read. Normally this is set automatically based on size of data. if false, cachedData is cleared.
  - isCaching
```
public boolean isCaching()
```
    Will this Variable be cached when read. Set externally by setCaching, or calculated based on total size < sizeToCache.
    This will always return false if caching isn't permitted.
    
    Returns:
    
    true is caching
  - hasCachedData
```
public boolean hasCachedData()
```
    If this has cached data, or source data.
  - toBuilder
```
public Variable.Builder<?> toBuilder()
```
    Turn into a mutable Builder. Can use toBuilder().build() to copy.
  - builder
```
public static Variable.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"

Class Variable

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

permitCaching

Method Detail

findDimensionIndex

getDatasetLocation

getArrayType

getDescription

getDimensions

getDimensionSet

getDimension

getDimensionsString

getElementSize

getEnumTypedef

getFileTypeId

getFullName

getNetcdfFile

getParentGroup

getParentStructure

getRank

getShape

getShape

getSection

getShortName

getSize

getUnitsString

isCoordinateVariable

isMemberOfStructure

isMetadata

isScalar

isUnlimited

isVariableLength

lookupEnumString

section

slice

reduce

readScalarByte

readScalarShort

readScalarInt

readScalarLong

readScalarFloat

readScalarDouble

readScalarString

readArray

readArray

proxyReadArray

proxyReadArray

getNameAndDimensions

getNameAndDimensions

toString

equals

hashCode

compareTo

attributes

findAttribute

findAttributeString

getSPobject

getSizeToCache

setCaching

isCaching

hasCachedData

toBuilder

builder