Package ucar.array

Class Arrays

java.lang.Object

ucar.array.Arrays

public class Arrays
extends Object

Static helper classes for Array

Method Summary

Modifier and Type	Method	Description
static <T> Array<T>	combine(ArrayType dataType, int[] shape, List<Array<?>> dataArrays)	Combine list of Array's by copying the underlying Array's into a single primitive array
static long	computeSize(int[] shape)	Compute total number of elements in the array.
static byte[]	convertCharToByte(char[] from)
static Object	copyPrimitiveArray(Array<?> data)	Copy all the data out of the Array into a 1d primitive array of the appropriate type.
static boolean	equalDoubles(Array<Double> arr1, Array<Double> arr2)	Compare values which must be equal to within Misc.defaultMaxRelativeDiffDouble.
static boolean	equalFloats(Array<Float> arr1, Array<Float> arr2)	Compare values which must be equal to within Misc.defaultMaxRelativeDiffFloat.
static boolean	equalNumbers(Array<Number> arr1, Array<Number> arr2)	Compare values which must be equal to within Misc.defaultMaxRelativeDiffFloat.
static <T> Array<T>	factory(ArrayType dataType, int[] shape, Object dataArray)	Create Array using java array of T, or java primitive array, as storage.
static <T> Array<T>	factoryFill(ArrayType dataType, int[] shape, Number fillValue)	Create Array using empty java array of T, or java primitive array, same size as shape.
static <T> Array<T>	flip(Array<T> org, int dim)	Create a new Array using same backing store as the org Array, by flipping the index so that it runs from shape[index]-1 to 0.
static com.google.protobuf.ByteString	getByteString(Array<Byte> from)	Convert the Array into a ByteString.
static MinMax	getMinMaxSkipMissingData(Array<? extends Number> a, IsMissingEvaluator eval)	Get the min and max of the array, skipping missing data if eval.hasMissing().
static <T> Array<T>	makeArray(ArrayType type, int npts, double start, double incr, int... shape)	Make a regular numeric array from a start and incr.
static String	makeStringFromChar(Array<Byte> from)	Create a String out of an Array\ of rank zero or one.
static Array<String>	makeStringsFromChar(Array<Byte> from)	Create an Array of Strings out of an Array\ of any rank.
static <T> Array<T>	permute(Array<T> org, int[] dims)	Create a new Array using same backing store as the org Array, by permuting the indices.
static <T> Array<T>	reduce(Array<T> org)	Create a new Array using same backing store as the org Array, by eliminating any dimensions with length one.
static <T> Array<T>	reduce(Array<T> org, int dim)	Create a new Array using same backing store as the org Array, by eliminating the specified dimension, which must have length 1.
static <T> Array<T>	reduceFirst(Array<T> org, int ndim)	Create a new Array using same backing store as the org Array, by eliminating the first ndim dimensions, iff they have length 1.
static int[]	removeVlen(int[] shape)	If there are any VLEN dimensions (length < 0), remove it and all dimensions to the right.
static <T> Array<T>	reshape(Array<T> org, int[] shape)	Create a new Array using same backing store with given shape
static <T> Array<T>	section(Array<T> org, Section section)	Create a new Array as a subsection of the org Array, without rank reduction.
static <T> Array<T>	slice(Array<T> org, int dim, int value)	Create a new Array using same backing store as the org Array, by fixing the specified dimension at the specified index value.
static double	sumDouble(Array<?> array)	Sum all the values in the Array as doubles.
static Array<Double>	toDouble(Array<?> array)	Convert a numeric array to double values.
static <T> Array<T>	transpose(Array<T> org, int dim1, int dim2)	Create a new Array using same backing store as the org Array, by transposing two of the indices.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

factory

public static <T> Array<T> factory(ArrayType dataType,
                                   int[] shape,
                                   Object dataArray)

Create Array using java array of T, or java primitive array, as storage. Do not use this for Vlens or Structures. The dataArray is not copied, for efficiency. The calling routine must not reuse the primitive array.

Parameters:

dataType - data type of the data. Vlen detected from the shape.

shape - multidimensional shape, must have same total length as dataArray.

dataArray - must be java primitive array or String[]

factoryFill

public static <T> Array<T> factoryFill(ArrayType dataType,
                                       int[] shape,
                                       Number fillValue)

Create Array using empty java array of T, or java primitive array, same size as shape. Do not use this for Vlens or Structures.*

Parameters:

shape - multidimensional shape

combine

public static <T> Array<T> combine(ArrayType dataType,
                                   int[] shape,
                                   List<Array<?>> dataArrays)

Combine list of Array's by copying the underlying Array's into a single primitive array

Parameters:

dataType - of the dataArrays and of the result.

shape - of the result.

dataArrays - the composite data.

Returns:

composite Array, formed by copying the dataArrays, must be of type dataType.

flip

public static <T> Array<T> flip(Array<T> org,
                                int dim)

Create a new Array using same backing store as the org Array, by flipping the index so that it runs from shape[index]-1 to 0.

Parameters:

org - original Array

dim - dimension to flip

Returns:

the new Array

permute

public static <T> Array<T> permute(Array<T> org,
                                   int[] dims)

Create a new Array using same backing store as the org Array, by permuting the indices.

Parameters:

org - original Array

dims - the old index dims[k] becomes the new kth index.

Returns:

the new Array

reshape

public static <T> Array<T> reshape(Array<T> org,
                                   int[] shape)

Create a new Array using same backing store with given shape

Parameters:

org - original Array

shape - the new shape

Returns:

the new Array

reduce

public static <T> Array<T> reduce(Array<T> org)

Create a new Array using same backing store as the org Array, by eliminating any dimensions with length one.

Parameters:

org - original Array

Returns:

the new Array, or the same Array if no reduction was done

reduce

public static <T> Array<T> reduce(Array<T> org,
                                  int dim)

Create a new Array using same backing store as the org Array, by eliminating the specified dimension, which must have length 1.

Parameters:

org - original Array

dim - dimension to eliminate: must be of length one.

Returns:

the new Array, or the same Array if no reduction was done

reduceFirst

public static <T> Array<T> reduceFirst(Array<T> org,
                                       int ndim)

Create a new Array using same backing store as the org Array, by eliminating the first ndim dimensions, iff they have length 1.

Parameters:

org - original Array

ndim - number of dimensions to reduce.

Returns:

the new Array, or the same Array if no reduction was done

section

public static <T> Array<T> section(Array<T> org,
                                   Section section)
                            throws InvalidRangeException

Create a new Array as a subsection of the org Array, without rank reduction. No data is moved, so the new Array references the same backing store as the original. Vlen is transferred over unchanged.

Parameters:

org - original Array

section - list of Ranges that specify the array subset. Must be same rank as original Array. A particular Range: 1) may be a subset, or 2) may be null, meaning use entire Range.

Returns:

the new Array

Throws:

InvalidRangeException

slice

public static <T> Array<T> slice(Array<T> org,
                                 int dim,
                                 int value)
                          throws InvalidRangeException

Create a new Array using same backing store as the org Array, by fixing the specified dimension at the specified index value. This reduces rank by 1.

Parameters:

org - original Array

dim - which dimension to fix

value - at what index value

Returns:

a new Array, with reduced rank.

Throws:

InvalidRangeException

transpose

public static <T> Array<T> transpose(Array<T> org,
                                     int dim1,
                                     int dim2)

Create a new Array using same backing store as the org Array, by transposing two of the indices.

Parameters:

org - original Array

dim1 - transpose these two indices

dim2 - transpose these two indices

Returns:

the new Array

computeSize

public static long computeSize(@Nullable
                               int[] shape)

Compute total number of elements in the array. Stop at vlen.

Parameters:

shape - length of array in each dimension.

Returns:

total number of elements in the array.

removeVlen

public static int[] removeVlen(int[] shape)

If there are any VLEN dimensions (length < 0), remove it and all dimensions to the right.

Parameters:

shape - multidimensional shape

Returns:

modified shape, if needed.

copyPrimitiveArray

public static Object copyPrimitiveArray(Array<?> data)

Copy all the data out of the Array into a 1d primitive array of the appropriate type.

sumDouble

public static double sumDouble(Array<?> array)

Sum all the values in the Array as doubles. Must be an array of Number.

toDouble

public static Array<Double> toDouble(Array<?> array)

Convert a numeric array to double values.

getMinMaxSkipMissingData

public static MinMax getMinMaxSkipMissingData(Array<? extends Number> a,
                                              @Nullable
                                              IsMissingEvaluator eval)

Get the min and max of the array, skipping missing data if eval.hasMissing().

makeArray

public static <T> Array<T> makeArray(ArrayType type,
                                     int npts,
                                     double start,
                                     double incr,
                                     int... shape)

Make a regular numeric array from a start and incr.

Parameters:

type - type of array

npts - number of points

start - starting value

incr - increment

shape - shape of resulting array. if not set, use 1 dim array of length npts.

makeStringsFromChar

public static Array<String> makeStringsFromChar(Array<Byte> from)

Create an Array of Strings out of an Array\ of any rank. If there is a null (zero) value in from, the String will end there. The null is not returned as part of the String.

Returns:

Array of Strings of rank - 1.

makeStringFromChar

public static String makeStringFromChar(Array<Byte> from)

Create a String out of an Array\ of rank zero or one. If there is a null (zero) value in from, the String will end there. The null is not returned as part of the String.

getByteString

public static com.google.protobuf.ByteString getByteString(Array<Byte> from)

Convert the Array into a ByteString.

convertCharToByte

public static byte[] convertCharToByte(char[] from)

equalDoubles

public static boolean equalDoubles(Array<Double> arr1,
                                   Array<Double> arr2)

Compare values which must be equal to within Misc.defaultMaxRelativeDiffDouble.

equalFloats

public static boolean equalFloats(Array<Float> arr1,
                                  Array<Float> arr2)

Compare values which must be equal to within Misc.defaultMaxRelativeDiffFloat.

equalNumbers

public static boolean equalNumbers(Array<Number> arr1,
                                   Array<Number> arr2)

Compare values which must be equal to within Misc.defaultMaxRelativeDiffFloat.