SparseRow (SystemML 0.15.0 API)

java.lang.Object
- org.apache.sysml.runtime.matrix.data.SparseRow

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

SparseRowScalar, SparseRowVector
```
public abstract class SparseRow
extends Object
implements Serializable
```
Base class for sparse row implementations such as sparse row vectors and sparse scalars (single value per row).

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description

SparseRow()

Constructors
Constructor and Description
`SparseRow()`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`abstract void`	`append(int col, double v)` Appends a value to the end of the sparse row.
`abstract void`	`compact()` In-place compaction of non-zero-entries; removes zero entries and shifts non-zero entries to the left if necessary.
`abstract double`	`get(int col)` Gets the value of a specified column.
`abstract int[]`	`indexes()` Get the index array of non-zero entries, co-aligned with the array of values.
`abstract boolean`	`isEmpty()` Indicates if the sparse row is empty, i.e., if is has size zero.
`abstract void`	`reset(int estnns, int maxnns)` Resets the sparse row to empty, after this call size and isEmpty are guaranteed to return 0 and true, respectively.
`abstract boolean`	`set(int col, double v)` Sets the value of a specified column with awareness of potential overwrites or deletes (set to value zero).
`abstract int`	`size()` Get the number of non-zero values of the sparse row.
`abstract void`	`sort()` In-place sort of column-index value pairs in order to allow binary search after constant-time append was used for reading unordered sparse rows.
`String`	`toString()`
`abstract double[]`	`values()` Get the value array of non-zero entries, co-aligned with the array of indexes.

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

- Constructor Detail
  - SparseRow
```
public SparseRow()
```
- Method Detail
  - size
```
public abstract int size()
```
    Get the number of non-zero values of the sparse row.
    
    Returns:
    
    number of non-zeros
  - isEmpty
```
public abstract boolean isEmpty()
```
    Indicates if the sparse row is empty, i.e., if is has size zero.
    
    Returns:
    
    true if empty
  - values
```
public abstract double[] values()
```
    Get the value array of non-zero entries, co-aligned with the array of indexes.
    
    Returns:
    
    array of values
  - indexes
```
public abstract int[] indexes()
```
    Get the index array of non-zero entries, co-aligned with the array of values.
    
    Returns:
    
    array of indexes
  - reset
```
public abstract void reset(int estnns,
                           int maxnns)
```
    Resets the sparse row to empty, after this call size and isEmpty are guaranteed to return 0 and true, respectively.
    
    Parameters:
    
    estnns - estimated number of non-zeros
    
    maxnns - maximum number of non-zeros, e.g., number of columns
  - set
```
public abstract boolean set(int col,
                            double v)
```
    Sets the value of a specified column with awareness of potential overwrites or deletes (set to value zero).
    
    Parameters:
    
    col - column index, zero-based
    
    v - value
    
    Returns:
    
    true if the size of the sparse row changed
  - append
```
public abstract void append(int col,
                            double v)
```
    Appends a value to the end of the sparse row.
    
    Parameters:
    
    col - column index, zero-based
    
    v - value
  - get
```
public abstract double get(int col)
```
    Gets the value of a specified column. If the column index does not exist in the sparse row, this call returns zero.
    
    Parameters:
    
    col - column index, zero-based
    
    Returns:
    
    value
  - sort
```
public abstract void sort()
```
    In-place sort of column-index value pairs in order to allow binary search after constant-time append was used for reading unordered sparse rows. We first check if already sorted and subsequently sort if necessary in order to get O(n) best case. Note: In-place sort is necessary in order to guarantee the memory estimate for operations that implicitly read that data set.
  - compact
```
public abstract void compact()
```
    In-place compaction of non-zero-entries; removes zero entries and shifts non-zero entries to the left if necessary.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Methods inherited from class java.lang.Object

SparseRow

size

isEmpty

values

indexes

reset

set

append

get

sort

compact

toString