DMatrix (xgboost4j 0.7 API)

java.lang.Object
- ml.dmlc.xgboost4j.java.DMatrix

```
public class DMatrix
extends Object
```
DMatrix for xgboost.

Author:

hzx

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`DMatrix.SparseType` sparse matrix type (CSR or CSC)

Field Summary

Fields
Modifier and Type	Field and Description
`protected long`	`handle`

Constructor Summary

Constructors
Modifier	Constructor and Description
	`DMatrix(float[] data, int nrow, int ncol)` create DMatrix from dense matrix
	`DMatrix(float[] data, int nrow, int ncol, float missing)` create DMatrix from dense matrix
	`DMatrix(Iterator iter, String cacheInfo)` Create DMatrix from iterator.
`protected`	`DMatrix(long handle)` used for DMatrix slice
	`DMatrix(long[] headers, int[] indices, float[] data, DMatrix.SparseType st)` Deprecated.
	`DMatrix(long[] headers, int[] indices, float[] data, DMatrix.SparseType st, int shapeParam)` Create DMatrix from Sparse matrix in CSR/CSC format.
	`DMatrix(String dataPath)` Create DMatrix by loading libsvm file from dataPath

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`dispose()`
`protected void`	`finalize()`
`float[]`	`getBaseMargin()` get base margin of the DMatrix
`long`	`getHandle()` Get the handle
`float[]`	`getLabel()` get label values
`float[]`	`getWeight()` get weight of the DMatrix
`long`	`rowNum()` get the row number of DMatrix
`void`	`saveBinary(String filePath)` save DMatrix to filePath
`void`	`setBaseMargin(float[] baseMargin)` if specified, xgboost will start from this init margin can be used to specify initial prediction to boost from
`void`	`setBaseMargin(float[][] baseMargin)` if specified, xgboost will start from this init margin can be used to specify initial prediction to boost from
`void`	`setGroup(int[] group)` Set group sizes of DMatrix (used for ranking)
`void`	`setLabel(float[] labels)` set label of dmatrix
`void`	`setWeight(float[] weights)` set weight of each instance
`DMatrix`	`slice(int[] rowIndex)` Slice the DMatrix and return a new DMatrix that only contains `rowIndex`.

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

- Field Detail
  - handle
```
protected long handle
```
- Constructor Detail
  - DMatrix
```
public DMatrix(Iterator iter,
       String cacheInfo)
        throws XGBoostError
```
    Create DMatrix from iterator.
    
    Parameters:
    
    iter - The data iterator of mini batch to provide the data.
    
    cacheInfo - Cache path information, used for external memory setting, can be null.
    
    Throws:
    
    XGBoostError
  - DMatrix
```
public DMatrix(String dataPath)
        throws XGBoostError
```
    Create DMatrix by loading libsvm file from dataPath
    
    Parameters:
    
    dataPath - The path to the data.
    
    Throws:
    
    XGBoostError
  - DMatrix
```
@Deprecated
public DMatrix(long[] headers,
                  int[] indices,
                  float[] data,
                  DMatrix.SparseType st)
        throws XGBoostError
```
    Deprecated.
    
    Create DMatrix from Sparse matrix in CSR/CSC format.
    
    Parameters:
    
    headers - The row index of the matrix.
    
    indices - The indices of presenting entries.
    
    data - The data content.
    
    st - Type of sparsity.
    
    Throws:
    
    XGBoostError
  - DMatrix
```
public DMatrix(long[] headers,
       int[] indices,
       float[] data,
       DMatrix.SparseType st,
       int shapeParam)
        throws XGBoostError
```
    Create DMatrix from Sparse matrix in CSR/CSC format.
    
    Parameters:
    
    headers - The row index of the matrix.
    
    indices - The indices of presenting entries.
    
    data - The data content.
    
    st - Type of sparsity.
    
    shapeParam - when st is CSR, it specifies the column number, otherwise it is taken as row number
    
    Throws:
    
    XGBoostError
  - DMatrix
```
public DMatrix(float[] data,
       int nrow,
       int ncol)
        throws XGBoostError
```
    create DMatrix from dense matrix
    
    Parameters:
    
    data - data values
    
    nrow - number of rows
    
    ncol - number of columns
    
    Throws:
    
    XGBoostError - native error
  - DMatrix
```
public DMatrix(float[] data,
       int nrow,
       int ncol,
       float missing)
        throws XGBoostError
```
    create DMatrix from dense matrix
    
    Parameters:
    
    data - data values
    
    nrow - number of rows
    
    ncol - number of columns
    
    missing - the specified value to represent the missing value
    
    Throws:
    
    XGBoostError
  - DMatrix
```
protected DMatrix(long handle)
```
    used for DMatrix slice
- Method Detail
  - setLabel
```
public void setLabel(float[] labels)
              throws XGBoostError
```
    set label of dmatrix
    
    Parameters:
    
    labels - labels
    
    Throws:
    
    XGBoostError - native error
  - setWeight
```
public void setWeight(float[] weights)
               throws XGBoostError
```
    set weight of each instance
    
    Parameters:
    
    weights - weights
    
    Throws:
    
    XGBoostError - native error
  - setBaseMargin
```
public void setBaseMargin(float[] baseMargin)
                   throws XGBoostError
```
    if specified, xgboost will start from this init margin can be used to specify initial prediction to boost from
    
    Parameters:
    
    baseMargin - base margin
    
    Throws:
    
    XGBoostError - native error
  - setBaseMargin
```
public void setBaseMargin(float[][] baseMargin)
                   throws XGBoostError
```
    if specified, xgboost will start from this init margin can be used to specify initial prediction to boost from
    
    Parameters:
    
    baseMargin - base margin
    
    Throws:
    
    XGBoostError - native error
  - setGroup
```
public void setGroup(int[] group)
              throws XGBoostError
```
    Set group sizes of DMatrix (used for ranking)
    
    Parameters:
    
    group - group size as array
    
    Throws:
    
    XGBoostError - native error
  - getLabel
```
public float[] getLabel()
                 throws XGBoostError
```
    get label values
    
    Returns:
    
    label
    
    Throws:
    
    XGBoostError - native error
  - getWeight
```
public float[] getWeight()
                  throws XGBoostError
```
    get weight of the DMatrix
    
    Returns:
    
    weights
    
    Throws:
    
    XGBoostError - native error
  - getBaseMargin
```
public float[] getBaseMargin()
                      throws XGBoostError
```
    get base margin of the DMatrix
    
    Returns:
    
    base margin
    
    Throws:
    
    XGBoostError - native error
  - slice
```
public DMatrix slice(int[] rowIndex)
              throws XGBoostError
```
    Slice the DMatrix and return a new DMatrix that only contains `rowIndex`.
    
    Parameters:
    
    rowIndex - row index
    
    Returns:
    
    sliced new DMatrix
    
    Throws:
    
    XGBoostError - native error
  - rowNum
```
public long rowNum()
            throws XGBoostError
```
    get the row number of DMatrix
    
    Returns:
    
    number of rows
    
    Throws:
    
    XGBoostError - native error
  - saveBinary
```
public void saveBinary(String filePath)
```
    save DMatrix to filePath
  - getHandle
```
public long getHandle()
```
    Get the handle
  - finalize
```
protected void finalize()
```
    Overrides:
    
    finalize in class Object
  - dispose
```
public void dispose()
```

Class DMatrix

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

handle

Constructor Detail

DMatrix

DMatrix

DMatrix

DMatrix

DMatrix

DMatrix

DMatrix

Method Detail

setLabel

setWeight

setBaseMargin

setBaseMargin

setGroup

getLabel

getWeight

getBaseMargin

slice

rowNum

saveBinary

getHandle

finalize

dispose