weka.core.json

## Class JSONInstances

- java.lang.Object
- - weka.core.json.JSONInstances

-     public class JSONInstances
      extends java.lang.Object

  Class for transforming Instances objects into JSON objects and vice versa. Missing values get stored as "?".
  Version:
    $Revision: 9664 $
  Author:
    FracPete (fracpete at waikato dot ac dot nz)
  See Also:
    `MISSING_VALUE`

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static java.lang.String` | `ATTRIBUTES` the attributes object.
    `static java.lang.String` | `CLASS` the class attribute indicator.
    `static java.lang.String` | `DATA` the data section.
    `static java.lang.String` | `DATEFORMAT` the dateformat attribute.
    `static java.lang.String` | `HEADER` the header section.
    `static java.lang.String` | `LABELS` the labels attribute.
    `static java.lang.String` | `MISSING_VALUE` the missing value indicator.
    `static java.lang.String` | `NAME` the name attribute.
    `static java.lang.String` | `RELATION` the relation name.
    `static java.lang.String` | `SPARSE` the sparse attribute.
    `static java.lang.String` | `SPARSE_SEPARATOR` the separator for index/value in case of sparse instances.
    `static java.lang.String` | `TYPE` the type attribute.
    `static java.lang.String` | `VALUES` the values attribute.
    `static java.lang.String` | `WEIGHT` the weight attribute.

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `JSONInstances()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `static void` | `main(java.lang.String[] args)` For testing only.
    `static Instances` | `toHeader(JSONNode json)` Turns a JSON object, if possible, into an Instances object (only header).
    `static Instances` | `toInstances(JSONNode json)` Turns a JSON object, if possible, into an Instances object.
    `static JSONNode` | `toJSON(Instances inst)` Turns the Instances object into a JSON object.

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### HEADER

          public static final java.lang.String HEADER

      the header section.
      See Also:
        Constant Field Values

    - #### DATA

          public static final java.lang.String DATA

      the data section.
      See Also:
        Constant Field Values

    - #### RELATION

          public static final java.lang.String RELATION

      the relation name.
      See Also:
        Constant Field Values

    - #### ATTRIBUTES

          public static final java.lang.String ATTRIBUTES

      the attributes object.
      See Also:
        Constant Field Values

    - #### NAME

          public static final java.lang.String NAME

      the name attribute.
      See Also:
        Constant Field Values

    - #### TYPE

          public static final java.lang.String TYPE

      the type attribute.
      See Also:
        Constant Field Values

    - #### CLASS

          public static final java.lang.String CLASS

      the class attribute indicator.
      See Also:
        Constant Field Values

    - #### LABELS

          public static final java.lang.String LABELS

      the labels attribute.
      See Also:
        Constant Field Values

    - #### WEIGHT

          public static final java.lang.String WEIGHT

      the weight attribute.
      See Also:
        Constant Field Values

    - #### DATEFORMAT

          public static final java.lang.String DATEFORMAT

      the dateformat attribute.
      See Also:
        Constant Field Values

    - #### SPARSE

          public static final java.lang.String SPARSE

      the sparse attribute.
      See Also:
        Constant Field Values

    - #### VALUES

          public static final java.lang.String VALUES

      the values attribute.
      See Also:
        Constant Field Values

    - #### SPARSE_SEPARATOR

          public static final java.lang.String SPARSE_SEPARATOR

      the separator for index/value in case of sparse instances.
      See Also:
        Constant Field Values

    - #### MISSING_VALUE

          public static final java.lang.String MISSING_VALUE

      the missing value indicator.
      See Also:
        Constant Field Values

  - ### Constructor Detail

    - #### JSONInstances

          public JSONInstances()

  - ### Method Detail

    - #### toInstances

          public static Instances toInstances(JSONNode json)

      Turns a JSON object, if possible, into an Instances object.
      Parameters:
        `json` - the JSON object to convert
      Returns:
        the generated Instances object, null if not possible

    - #### toHeader

          public static Instances toHeader(JSONNode json)

      Turns a JSON object, if possible, into an Instances object (only header).
      Parameters:
        `json` - the JSON object to convert
      Returns:
        the generated Instances header object, null if not possible

    - #### toJSON

          public static JSONNode toJSON(Instances inst)

      Turns the Instances object into a JSON object.
      Parameters:
        `inst` - the Instances to turn into a JSON object
      Returns:
        the JSON object

    - #### main

          public static void main(java.lang.String[] args)
                           throws java.lang.Exception

      For testing only.
      Parameters:
        `args` - expects a dataset as first parameter
      Throws:
        `java.lang.Exception` - if something goes wrong