## org.das2.qds.LDataSet

rank 0,1,2,3 or 4 dataset backed by long array (8 byte signed numbers). Note access to the array is still done via doubles.

## version

## addValue

addValue( int i0, double value ) → void

add this value to the current value.

### Parameters

i0 - the index
value - the value, which is cast to this internal type.

### Returns:

void (returns nothing)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## addValue

addValue( int i0, int i1, double value ) → void

add this value to the current value.

### Parameters

i0 - the index
i1 - the index
value - the value, which is cast to this internal type.

### Returns:

void (returns nothing)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## capability

capability( java.lang.Class clazz ) → Object

Clients should use this instead of casting the class to the capability class.

### Parameters

clazz - the class, such as WritableDataSet.class or LongReadAccess

### Returns:

null or the capability if exists, such as WritableDataSet

### See Also:

https://github.com/autoplot/dev/blob/master/demos/2019/20190219/demoLongReadAccess.jy
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## create

create( int[] qube ) → org.das2.qds.LDataSet

Makes an array from array of dimension sizes. The result will have rank qube.length().

### Parameters

qube - array specifying the rank and size of each dimension

### Returns:

LDataSet
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## createRank1

createRank1( int len0 ) → org.das2.qds.LDataSet

create a rank 1 dataset backed by array of longs.

### Parameters

len0 - length of the dimension

### Returns:

rank 1 qube dataset of backed by array of longs.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## createRank2

createRank2( int len0, int len1 ) → org.das2.qds.LDataSet

create a rank 2 qube dataset backed by array of longs.

### Parameters

len0 - length of the dimension
len1 - length of the dimension

### Returns:

rank 2 qube dataset of backed by array of longs.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## createRank3

createRank3( int len0, int len1, int len2 ) → org.das2.qds.LDataSet

create a rank 3 qube dataset backed by array of longs.

### Parameters

len0 - length of the dimension
len1 - length of the dimension
len2 - length of the dimension

### Returns:

rank 3 qube dataset of backed by array of longs.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## createRank4

createRank4( int len0, int len1, int len2, int len3 ) → org.das2.qds.LDataSet

create a rank 4 qube dataset backed by array of longs.

### Parameters

len0 - length of the dimension
len1 - length of the dimension
len2 - length of the dimension
len3 - length of the dimension

### Returns:

rank 4 qube dataset of backed by array of longs.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## putValue

putValue( double value ) → void

### Parameters

value - a double

### Returns:

void (returns nothing)
[search for examples] [view on GitHub] [view on old javadoc] [view source]
putValue( int i0, double value ) → void [view source]
putValue( int i0, int i1, double value ) → void [view source]
putValue( int i0, int i1, int i2, double value ) → void [view source]
putValue( int i0, int i1, int i2, int i3, double value ) → void [view source]

## slice

slice( int i ) → QDataSet

the slice operator is better implemented here. Presently, we use System.arraycopy to copy out the data, but this could be re-implemented along with an offset parameter so the original data can be used to back the data.

### Parameters

i - the index

### Returns:

a rank N-1 slice of the data.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## trim

trim( int start, int end ) → QDataSet

trim operator copies the data into a new dataset.

### Parameters

start - the first index
end - the last index, exclusive

### Returns:

a shorter dataset of the same rank.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## value

value( ) → double

### Returns:

double
[search for examples] [view on GitHub] [view on old javadoc] [view source]
value( int i0 ) → double [view source]
value( int i0, int i1 ) → double [view source]
value( int i0, int i1, int i2 ) → double [view source]
value( int i0, int i1, int i2, int i3 ) → double [view source]

## wrap

wrap( long[] data, int[] qube ) → org.das2.qds.LDataSet

Wraps an array from array of dimension sizes. The result will have rank qube.length(). For rank 0, data is 1-element array.

### Parameters

data - array containing the data, with the last dimension contiguous in memory.
qube - array specifying the rank and size of each dimension

### Returns:

the array as a QDataSet
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## wrap

wrap( long[] back, int rank, int len0, int len1, int len2, int len3 ) → org.das2.qds.LDataSet

Wraps an array from array of dimension sizes. The result will have rank qube.length().

### Parameters

back - the backing array
rank - the rank
len0 - length of the dimension
len1 - length of the dimension
len2 - length of the dimension
len3 - length of the dimension

### Returns:

the array as a QDataSet
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## wrap

wrap( long[] back ) → org.das2.qds.LDataSet

creates a rank1 LDataSet by wrapping an existing array.

### Parameters

back - the new backing array

### Returns:

the dataset
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## wrap

wrap( long[] back, int nx, int ny ) → org.das2.qds.LDataSet

creates an LDataSet by wrapping an existing array, aliasing it to rank 2.

### Parameters

back - the new backing array
nx - number of elements in the zeroth index
ny - number of elements in the first index

### Returns:

the dataset
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## wrap

wrap( long[] back, int nx, int ny, int nz ) → org.das2.qds.LDataSet

creates an LDataSet by wrapping an existing array, aliasing it to rank 3.

### Parameters

back - the new backing array
nx - number of elements in the zeroth index
ny - number of elements in the first index
nz - number of elements in the second index

### Returns:

the dataset
[search for examples] [view on GitHub] [view on old javadoc] [view source]