CDMUtil (d4cdmshared 4.6.8 API)

java.lang.Object
- dap4.cdmshared.CDMUtil

```
public abstract class CDMUtil
extends java.lang.Object
```
CDM related Constants and utilities common to client and server code

Constructor Summary

Constructors
Constructor and Description

CDMUtil()

Constructors
Constructor and Description
`CDMUtil()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static java.lang.Class`	`cdmElementClass(ucar.ma2.DataType dt)`
`static dap4.core.dmr.DapType`	`cdmtype2daptype(ucar.ma2.DataType datatype, boolean unsigned)`
`static int[]`	`computeEffectiveShape(java.util.List<dap4.core.dmr.DapDimension> dimset)` Compute the shape inferred from a set of slices.
`static java.lang.Object`	`convertVector(dap4.core.dmr.DapType dsttype, dap4.core.dmr.DapType srctype, java.lang.Object src)` Convert an array of one type of values to another type
`static java.util.List<ucar.ma2.Range>`	`createCDMRanges(java.util.List<dap4.core.util.Slice> slices)`
`static java.util.List<dap4.core.util.Slice>`	`createSlices(java.util.List<ucar.ma2.Range> rangelist)` Convert a list of ucar.ma2.Range to a list of Slice More or less the inverst of create CDMRanges
`static java.lang.Object`	`createVector(dap4.core.dmr.AtomicType atype, long count)` Given an arbitrary Array (including ArrayStructure), produce a new Array that represents the slice defined by the section.
`static ucar.ma2.DataType`	`daptype2cdmtype(dap4.core.dmr.DapType daptype)`
`static int`	`daptypeSize(dap4.core.dmr.AtomicType atomtype)` Conmpute the size, in databuffer, of the daptype wrt to a serialization; 0 if undefined.
`static java.util.List<ucar.ma2.Range>`	`dimsetToRanges(java.util.List<dap4.core.dmr.DapDimension> dimset)` Convert a Section + variable to a constraint static public View sectionToView(CDMDSP dsp, Variable v, Section section) throws DapException { if(section == null \|\| section.getRank() == 0) return null; // Get the corresponding DapNode DapVariable dv = (DapVariable) dsp.getNode().get(v); if(dv == null) throw new DapException("Variable has no corresponding dap node: " + v.getFullName()); // Get the structure path wrt DapDataset for dv // and use path plus the Section to construct a constraint List structpath = DapUtil.getStructurePath(dv); List ranges = section.getRanges(); View view = new View(dmr); int next = 0; for(int i = 0;i < structpath.size();i++) { dv = structpath.get(i); int rank = dv.getRank(); ViewVariable vv = new ViewVariable(dv); List slices = new ArrayList(rank); for(int j = 0;j < rank;j++, next++) { if(next >= ranges.size()) throw new DapException("Range::Rank mismatch"); Range range = ranges.get(next); Slice slice = new Slice(range.first(), range.last(), range.stride()).validate(); slices.add(slice); } vv.setSlices(slices); view.put(dv, vv); } view.validate(View.EXPAND); return view; }
`static ucar.ma2.DataType`	`enumtypefor(dap4.core.dmr.DapType dt)`
`static double`	`extractDoubleValue(dap4.core.dmr.AtomicType atomtype, dap4.dap4shared.D4DataAtomic dataset, int index)` Extract, as a double, value from a (presumably) atomic typed array of values; dataset position is presumed correct.
`static long`	`extractLongValue(dap4.core.dmr.AtomicType atomtype, dap4.dap4shared.D4DataAtomic dataset, long index)` Extract, as a long, value from a (presumably) atomic typed array of values; dataset position is presumed correct.
`static java.lang.String`	`getChecksumString(byte[] checksum)`
`static boolean`	`hasVLEN(java.util.List<ucar.ma2.Range> ranges)`
`static boolean`	`hasVLEN(ucar.nc2.Variable v)` Test if any dimension is variable length
`static boolean`	`isWhole(java.util.List<ucar.ma2.Range> rangelist, java.util.List<dap4.core.dmr.DapDimension> dimset, int start, int stop)` Test a List against a List to see if the range list represents the whole set of dimensions within the specified indices.
`static boolean`	`isWhole(java.util.List<ucar.ma2.Range> rangelist, java.util.List<dap4.core.util.Slice> slices)` Test a List against a List to see if the range list is whole wrt the slices
`static boolean`	`isWhole(java.util.List<ucar.ma2.Range> rangelist, ucar.nc2.Variable var)` Test a List against the CDM variable's dimensions to see if the range list is whole wrt the dimensions
`static java.util.List<dap4.core.util.Slice>`	`shapeToSlices(int[] shape)`
`static ucar.nc2.Variable`	`unwrap(ucar.nc2.Variable var)` NetcdfDataset can end up wrapping a variable in multiple wrapping classes (e.g.
`static ucar.nc2.NetcdfFile`	`unwrapfile(ucar.nc2.NetcdfFile file)` NetcdfDataset can wrap a NetcdfFile.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - CDMUtil
```
public CDMUtil()
```
- Method Detail
  - createSlices
```
public static java.util.List<dap4.core.util.Slice> createSlices(java.util.List<ucar.ma2.Range> rangelist)
                                                         throws dap4.core.util.DapException
```
    Convert a list of ucar.ma2.Range to a list of Slice More or less the inverst of create CDMRanges
    
    Parameters:
    
    rangelist - the set of ucar.ma2.Range
    
    Throws:
    
    dap4.core.util.DapException
  - isWhole
```
public static boolean isWhole(java.util.List<ucar.ma2.Range> rangelist,
                              java.util.List<dap4.core.dmr.DapDimension> dimset,
                              int start,
                              int stop)
                       throws dap4.core.util.DapException
```
    Test a List against a List to see if the range list represents the whole set of dimensions within the specified indices.
    
    Parameters:
    
    rangelist - the set of ucar.ma2.Range
    
    dimset - the set of DapDimensions
    
    start - start looking here
    
    stop - stop looking here
    
    Throws:
    
    dap4.core.util.DapException
  - isWhole
```
public static boolean isWhole(java.util.List<ucar.ma2.Range> rangelist,
                              java.util.List<dap4.core.util.Slice> slices)
                       throws dap4.core.util.DapException
```
    Test a List against a List to see if the range list is whole wrt the slices
    
    Parameters:
    
    rangelist - the set of ucar.ma2.Range
    
    slices - the set of slices
    
    Throws:
    
    dap4.core.util.DapException
  - isWhole
```
public static boolean isWhole(java.util.List<ucar.ma2.Range> rangelist,
                              ucar.nc2.Variable var)
                       throws dap4.core.util.DapException
```
    Test a List against the CDM variable's dimensions to see if the range list is whole wrt the dimensions
    
    Parameters:
    
    rangelist - the set of ucar.ma2.Range
    
    var - the cdm var
    
    Throws:
    
    dap4.core.util.DapException
  - createCDMRanges
```
public static java.util.List<ucar.ma2.Range> createCDMRanges(java.util.List<dap4.core.util.Slice> slices)
                                                      throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - unwrap
```
public static ucar.nc2.Variable unwrap(ucar.nc2.Variable var)
```
    NetcdfDataset can end up wrapping a variable in multiple wrapping classes (e.g. VariableDS). Goal of this procedure is to get down to the lowest level Variable instance
    
    Parameters:
    
    var - possibly wrapped variable
    
    Returns:
    
    the lowest level Variable instance
  - unwrapfile
```
public static ucar.nc2.NetcdfFile unwrapfile(ucar.nc2.NetcdfFile file)
```
    NetcdfDataset can wrap a NetcdfFile. Goal of this procedure is to get down to the lowest level NetcdfFile instance.
    
    Parameters:
    
    file - NetcdfFile or NetcdfDataset
    
    Returns:
    
    the lowest level NetcdfFile instance
  - hasVLEN
```
public static boolean hasVLEN(java.util.List<ucar.ma2.Range> ranges)
```
  - hasVLEN
```
public static boolean hasVLEN(ucar.nc2.Variable v)
```
    Test if any dimension is variable length
  - enumtypefor
```
public static ucar.ma2.DataType enumtypefor(dap4.core.dmr.DapType dt)
```
  - cdmtype2daptype
```
public static dap4.core.dmr.DapType cdmtype2daptype(ucar.ma2.DataType datatype,
                                                    boolean unsigned)
```
  - daptype2cdmtype
```
public static ucar.ma2.DataType daptype2cdmtype(dap4.core.dmr.DapType daptype)
```
  - daptypeSize
```
public static int daptypeSize(dap4.core.dmr.AtomicType atomtype)
```
    Conmpute the size, in databuffer, of the daptype wrt to a serialization; 0 if undefined.
    
    Parameters:
    
    atomtype - The type of interest
    
    Returns:
    
    the size, in databuffer
  - cdmElementClass
```
public static java.lang.Class cdmElementClass(ucar.ma2.DataType dt)
```
  - computeEffectiveShape
```
public static int[] computeEffectiveShape(java.util.List<dap4.core.dmr.DapDimension> dimset)
```
    Compute the shape inferred from a set of slices. 'Effective' means that any trailing vlen will be ignored.
    
    Parameters:
    
    dimset - from which to generate shape
    
    Returns:
  - extractLongValue
```
public static long extractLongValue(dap4.core.dmr.AtomicType atomtype,
                                    dap4.dap4shared.D4DataAtomic dataset,
                                    long index)
                             throws dap4.core.data.DataException
```
    Extract, as a long, value from a (presumably) atomic typed array of values; dataset position is presumed correct.
    
    Parameters:
    
    atomtype - type of object to extract
    
    dataset - D4Data containing the objects
    
    index - Which element of dataset to read
    
    Returns:
    
    resulting value as a long
    
    Throws:
    
    ucar.ma2.ForbiddenConversionException - if cannot convert to long
    
    dap4.core.data.DataException
  - extractDoubleValue
```
public static double extractDoubleValue(dap4.core.dmr.AtomicType atomtype,
                                        dap4.dap4shared.D4DataAtomic dataset,
                                        int index)
                                 throws dap4.core.data.DataException
```
    Extract, as a double, value from a (presumably) atomic typed array of values; dataset position is presumed correct.
    
    Parameters:
    
    atomtype - type of object to extract
    
    dataset - D4Data containing the objects
    
    index - Which element of dataset to read
    
    Returns:
    
    resulting value as a double
    
    Throws:
    
    ucar.ma2.ForbiddenConversionException - if cannot convert to double
    
    dap4.core.data.DataException
  - convertVector
```
public static java.lang.Object convertVector(dap4.core.dmr.DapType dsttype,
                                             dap4.core.dmr.DapType srctype,
                                             java.lang.Object src)
```
    Convert an array of one type of values to another type
    
    Parameters:
    
    dsttype - target type
    
    srctype - source type
    
    src - array of values to convert
    
    Returns:
    
    resulting array of converted values as an object
  - createVector
```
public static java.lang.Object createVector(dap4.core.dmr.AtomicType atype,
                                            long count)
```
    Given an arbitrary Array (including ArrayStructure), produce a new Array that represents the slice defined by the section. For now, we create a simple array of the relevant type and fill it by extracting the values specified by the section. param array the array from which the section is extracted param section determines what to extract throws DapException returns the slice array
  - getChecksumString
```
public static java.lang.String getChecksumString(byte[] checksum)
```
  - dimsetToRanges
```
public static java.util.List<ucar.ma2.Range> dimsetToRanges(java.util.List<dap4.core.dmr.DapDimension> dimset)
                                                     throws dap4.core.util.DapException
```
    Convert a Section + variable to a constraint static public View sectionToView(CDMDSP dsp, Variable v, Section section) throws DapException { if(section == null || section.getRank() == 0) return null; // Get the corresponding DapNode DapVariable dv = (DapVariable) dsp.getNode().get(v); if(dv == null) throw new DapException("Variable has no corresponding dap node: " + v.getFullName()); // Get the structure path wrt DapDataset for dv // and use path plus the Section to construct a constraint List structpath = DapUtil.getStructurePath(dv); List ranges = section.getRanges(); View view = new View(dmr); int next = 0; for(int i = 0;i < structpath.size();i++) { dv = structpath.get(i); int rank = dv.getRank(); ViewVariable vv = new ViewVariable(dv); List slices = new ArrayList(rank); for(int j = 0;j < rank;j++, next++) { if(next >= ranges.size()) throw new DapException("Range::Rank mismatch"); Range range = ranges.get(next); Slice slice = new Slice(range.first(), range.last(), range.stride()).validate(); slices.add(slice); } vv.setSlices(slices); view.put(dv, vv); } view.validate(View.EXPAND); return view; }
    
    Throws:
    
    dap4.core.util.DapException
  - shapeToSlices
```
public static java.util.List<dap4.core.util.Slice> shapeToSlices(int[] shape)
                                                          throws dap4.core.util.DapException
```
    Throws:
    
    dap4.core.util.DapException

Class CDMUtil

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

CDMUtil

Method Detail

createSlices

isWhole

isWhole

isWhole

createCDMRanges

unwrap

unwrapfile

hasVLEN

hasVLEN

enumtypefor

cdmtype2daptype

daptype2cdmtype

daptypeSize

cdmElementClass

computeEffectiveShape

extractLongValue

extractDoubleValue

convertVector

createVector

getChecksumString

dimsetToRanges

shapeToSlices