org.das2.qds

Interface DataSetIterator

All Known Implementing Classes:

IndexListDataSetIterator, QubeDataSetIterator

public interface DataSetIterator

Iterator for accessing each value of a dataset. See https://jfaden.net/jenkins/job/autoplot-test037/ws/dataSetIterator.jy

Method Summary

Modifier and Type	Method and Description
DDataSet	createEmptyDs() return a dataset that will have the same geometry at the dataset implied by each dimension iterator.
QDataSet	getRank0Value(QDataSet ds) get the rank 0 data set the current iterator position.
double	getValue(QDataSet ds) get the value from ds at the current iterator position.
boolean	hasNext() return true while the iterator has a next element.
int	index(int dim) return the current index for the dimension.
int	length(int dim) return the length of the dimension, or the length reported by the iterator.
void	next() iterate to the next position.
void	putRank0Value(WritableDataSet ds, QDataSet v) replace the value in ds at the current iterator position.
void	putValue(WritableDataSet ds, double v) replace the value in ds at the current iterator position.
int	rank() return the rank of the dataset which the iterator will walk through.

Method Detail

hasNext

boolean hasNext()

return true while the iterator has a next element.

Returns:

true while the iterator has a next element.

index

int index(int dim)

return the current index for the dimension.

Parameters:

dim - the dimension number (0<=dim<inputRank)

Returns:

the current index.

length

int length(int dim)

return the length of the dimension, or the length reported by the iterator. Use caution, because this does not imply that the result of the iteration is a qube and does not account for slices. (TODO: does this mean that as we iterate through, the length depends on the current index?)

Parameters:

dim - the dimension number (0<=dim<inputRank)

Returns:

the length of the dimension

next

void next()

iterate to the next position.

getValue

double getValue(QDataSet ds)

get the value from ds at the current iterator position.

Parameters:

ds - a dataset with compatible geometry as the iterator's geometry.

Returns:

the value of ds at the current iterator position.

getRank0Value

QDataSet getRank0Value(QDataSet ds)

get the rank 0 data set the current iterator position.

Parameters:

ds -

Returns:

units

putValue

void putValue(WritableDataSet ds,
              double v)

replace the value in ds at the current iterator position.

Parameters:

ds - a writable dataset with compatible geometry as the iterator's geometry.

v - the value to insert.

putRank0Value

void putRank0Value(WritableDataSet ds,
                   QDataSet v)

replace the value in ds at the current iterator position.

Parameters:

ds - a writable dataset with compatible geometry as the iterator's geometry.

v - the rank 0 value to insert

rank

int rank()

return the rank of the dataset which the iterator will walk through. Note this needn't be the same rank as the dataset! For example, when QubeDataSetIterator walks through ds[:,0,:], the rank is 2 even though ds is rank 3.

Returns:

the rank of the dataset which the iterator will walk through.

createEmptyDs

DDataSet createEmptyDs()

return a dataset that will have the same geometry at the dataset implied by each dimension iterator. This is introduced to encapsulate this dangerous code to here where it could be done correctly. Right now this assumes QUBES. Do not pass the result of this into the putValue of this iterator, the result should have its own iterator.

Returns:

a dataset that will have the same geometry at the dataset implied by each dimension iterator.

See Also:

QubeDataSetIterator.createEmptyDs()