DistributedLDAModel (Spark 2.0.2 JavaDoc)

Object
- org.apache.spark.ml.PipelineStage
- - org.apache.spark.ml.Transformer
  - - org.apache.spark.ml.Model<LDAModel>
    - - org.apache.spark.ml.clustering.LDAModel
      - org.apache.spark.ml.clustering.DistributedLDAModel

All Implemented Interfaces:

java.io.Serializable, Params, Identifiable, MLWritable
```
public class DistributedLDAModel
extends LDAModel
```
:: Experimental ::
Distributed model fitted by LDA. This type of model is currently only produced by Expectation-Maximization (EM).
This model stores the inferred topics, the full training dataset, and the topic distribution for each training document.
param: oldLocalModelOption Used to implement oldLocalModel as a lazy val, but keeping copy() cheap.

See Also:
Serialized Form

Method Summary

Methods
Modifier and Type	Method and Description
`static IntParam`	`checkpointInterval()`
`IntParam`	`checkpointInterval()` Param for set checkpoint interval (>= 1) or disable checkpoint (-1).
`static Params`	`clear(Param<?> param)`
`DistributedLDAModel`	`copy(ParamMap extra)` Creates a copy of this instance with the same UID and some extra params.
`void`	`deleteCheckpointFiles()` :: DeveloperApi ::
`static Dataset<Row>`	`describeTopics()`
`static Dataset<Row>`	`describeTopics(int maxTermsPerTopic)`
`static DoubleArrayParam`	`docConcentration()`
`DoubleArrayParam`	`docConcentration()` Concentration parameter (commonly named "alpha") for the prior placed on documents' distributions over topics ("theta").
`static Vector`	`estimatedDocConcentration()`
`static String`	`explainParam(Param<?> param)`
`static String`	`explainParams()`
`static ParamMap`	`extractParamMap()`
`static ParamMap`	`extractParamMap(ParamMap extra)`
`static Param<String>`	`featuresCol()`
`Param<String>`	`featuresCol()` Param for features column name.
`static <T> scala.Option<T>`	`get(Param<T> param)`
`String[]`	`getCheckpointFiles()` :: DeveloperApi ::
`static int`	`getCheckpointInterval()`
`int`	`getCheckpointInterval()`
`static <T> scala.Option<T>`	`getDefault(Param<T> param)`
`static double[]`	`getDocConcentration()`
`double[]`	`getDocConcentration()`
`static String`	`getFeaturesCol()`
`String`	`getFeaturesCol()`
`static int`	`getK()`
`int`	`getK()`
`static boolean`	`getKeepLastCheckpoint()`
`boolean`	`getKeepLastCheckpoint()`
`static double`	`getLearningDecay()`
`double`	`getLearningDecay()`
`static double`	`getLearningOffset()`
`double`	`getLearningOffset()`
`static int`	`getMaxIter()`
`int`	`getMaxIter()`
`Vector`	`getOldDocConcentration()` Get docConcentration used by spark.mllib LDA
`LDAOptimizer`	`getOldOptimizer()`
`double`	`getOldTopicConcentration()` Get topicConcentration used by spark.mllib LDA
`static boolean`	`getOptimizeDocConcentration()`
`boolean`	`getOptimizeDocConcentration()`
`static String`	`getOptimizer()`
`String`	`getOptimizer()`
`static <T> T`	`getOrDefault(Param<T> param)`
`static Param<Object>`	`getParam(String paramName)`
`static long`	`getSeed()`
`long`	`getSeed()`
`static double`	`getSubsamplingRate()`
`double`	`getSubsamplingRate()`
`static double`	`getTopicConcentration()`
`double`	`getTopicConcentration()`
`static String`	`getTopicDistributionCol()`
`String`	`getTopicDistributionCol()`
`static <T> boolean`	`hasDefault(Param<T> param)`
`static boolean`	`hasParam(String paramName)`
`static boolean`	`hasParent()`
`static boolean`	`isDefined(Param<?> param)`
`boolean`	`isDistributed()` Indicates whether this instance is of type `DistributedLDAModel`
`static boolean`	`isSet(Param<?> param)`
`static IntParam`	`k()`
`IntParam`	`k()` Param for the number of topics (clusters) to infer.
`static BooleanParam`	`keepLastCheckpoint()`
`BooleanParam`	`keepLastCheckpoint()` For EM optimizer only: `optimizer` = "em".
`static DoubleParam`	`learningDecay()`
`DoubleParam`	`learningDecay()` For Online optimizer only: `optimizer` = "online".
`static DoubleParam`	`learningOffset()`
`DoubleParam`	`learningOffset()` For Online optimizer only: `optimizer` = "online".
`static DistributedLDAModel`	`load(String path)`
`static double`	`logLikelihood(Dataset<?> dataset)`
`static double`	`logPerplexity(Dataset<?> dataset)`
`double`	`logPrior()` Log probability of the current parameter estimate: log P(topics, topic distributions for docs \| Dirichlet hyperparameters)
`static IntParam`	`maxIter()`
`IntParam`	`maxIter()` Param for maximum number of iterations (>= 0).
`static BooleanParam`	`optimizeDocConcentration()`
`BooleanParam`	`optimizeDocConcentration()` For Online optimizer only (currently): `optimizer` = "online".
`static Param<String>`	`optimizer()`
`Param<String>`	`optimizer()` Optimizer or inference algorithm used to estimate the LDA model.
`static Param<?>[]`	`params()`
`static void`	`parent_$eq(Estimator<M> x$1)`
`static Estimator<M>`	`parent()`
`static MLReader<DistributedLDAModel>`	`read()`
`static void`	`save(String path)`
`static LongParam`	`seed()`
`LongParam`	`seed()` Param for random seed.
`static <T> Params`	`set(Param<T> param, T value)`
`static LDAModel`	`setFeaturesCol(String value)`
`static M`	`setParent(Estimator<M> parent)`
`static LDAModel`	`setSeed(long value)`
`static DoubleParam`	`subsamplingRate()`
`DoubleParam`	`subsamplingRate()` For Online optimizer only: `optimizer` = "online".
`static String[]`	`supportedOptimizers()`
`String[]`	`supportedOptimizers()` Supported values for Param `optimizer`.
`LocalLDAModel`	`toLocal()` Convert this distributed model to a local representation.
`static DoubleParam`	`topicConcentration()`
`DoubleParam`	`topicConcentration()` Concentration parameter (commonly named "beta" or "eta") for the prior placed on topics' distributions over terms.
`static Param<String>`	`topicDistributionCol()`
`Param<String>`	`topicDistributionCol()` Output column with estimates of the topic mixture distribution for each document (often called "theta" in the literature).
`static Matrix`	`topicsMatrix()`
`static String`	`toString()`
`double`	`trainingLogLikelihood()` Log likelihood of the observed tokens in the training set, given the current parameter estimates: log P(docs \| topics, topic distributions for docs, Dirichlet hyperparameters)
`static Dataset<Row>`	`transform(Dataset<?> dataset)`
`static Dataset<Row>`	`transform(Dataset<?> dataset, ParamMap paramMap)`
`static Dataset<Row>`	`transform(Dataset<?> dataset, ParamPair<?> firstParamPair, ParamPair<?>... otherParamPairs)`
`static Dataset<Row>`	`transform(Dataset<?> dataset, ParamPair<?> firstParamPair, scala.collection.Seq<ParamPair<?>> otherParamPairs)`
`static StructType`	`transformSchema(StructType schema)`
`static String`	`uid()`
`StructType`	`validateAndTransformSchema(StructType schema)` Validates and transforms the input schema.
`static void`	`validateParams()`
`static int`	`vocabSize()`
`MLWriter`	`write()` Returns an `MLWriter` instance for this ML instance.

Methods inherited from class org.apache.spark.ml.clustering.LDAModel
describeTopics, describeTopics, estimatedDocConcentration, logLikelihood, logPerplexity, setFeaturesCol, setSeed, topicsMatrix, transform, transformSchema, uid, vocabSize

Methods inherited from class org.apache.spark.ml.Model
hasParent, parent, setParent

Methods inherited from class org.apache.spark.ml.Transformer
transform, transform, transform

Methods inherited from class Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.spark.ml.param.Params
clear, copyValues, defaultCopy, defaultParamMap, explainParam, explainParams, extractParamMap, extractParamMap, get, getDefault, getOrDefault, getParam, hasDefault, hasParam, isDefined, isSet, paramMap, params, set, set, set, setDefault, setDefault, shouldOwn, validateParams

Methods inherited from interface org.apache.spark.ml.util.Identifiable
toString

Methods inherited from interface org.apache.spark.ml.util.MLWritable
save

- Method Detail
  - read
```
public static MLReader<DistributedLDAModel> read()
```
  - load
```
public static DistributedLDAModel load(String path)
```
  - toString
```
public static String toString()
```
  - params
```
public static Param<?>[] params()
```
  - validateParams
```
public static void validateParams()
```
  - explainParam
```
public static String explainParam(Param<?> param)
```
  - explainParams
```
public static String explainParams()
```
  - isSet
```
public static final boolean isSet(Param<?> param)
```
  - isDefined
```
public static final boolean isDefined(Param<?> param)
```
  - hasParam
```
public static boolean hasParam(String paramName)
```
  - getParam
```
public static Param<Object> getParam(String paramName)
```
  - set
```
public static final <T> Params set(Param<T> param,
             T value)
```
  - get
```
public static final <T> scala.Option<T> get(Param<T> param)
```
  - clear
```
public static final Params clear(Param<?> param)
```
  - getOrDefault
```
public static final <T> T getOrDefault(Param<T> param)
```
  - getDefault
```
public static final <T> scala.Option<T> getDefault(Param<T> param)
```
  - hasDefault
```
public static final <T> boolean hasDefault(Param<T> param)
```
  - extractParamMap
```
public static final ParamMap extractParamMap(ParamMap extra)
```
  - extractParamMap
```
public static final ParamMap extractParamMap()
```
  - transform
```
public static Dataset<Row> transform(Dataset<?> dataset,
                     ParamPair<?> firstParamPair,
                     scala.collection.Seq<ParamPair<?>> otherParamPairs)
```
  - transform
```
public static Dataset<Row> transform(Dataset<?> dataset,
                     ParamMap paramMap)
```
  - transform
```
public static Dataset<Row> transform(Dataset<?> dataset,
                     ParamPair<?> firstParamPair,
                     ParamPair<?>... otherParamPairs)
```
  - parent
```
public static Estimator<M> parent()
```
  - parent_$eq
```
public static void parent_$eq(Estimator<M> x$1)
```
  - setParent
```
public static M setParent(Estimator<M> parent)
```
  - hasParent
```
public static boolean hasParent()
```
  - featuresCol
```
public static final Param<String> featuresCol()
```
  - getFeaturesCol
```
public static final String getFeaturesCol()
```
  - maxIter
```
public static final IntParam maxIter()
```
  - getMaxIter
```
public static final int getMaxIter()
```
  - seed
```
public static final LongParam seed()
```
  - getSeed
```
public static final long getSeed()
```
  - checkpointInterval
```
public static final IntParam checkpointInterval()
```
  - getCheckpointInterval
```
public static final int getCheckpointInterval()
```
  - k
```
public static final IntParam k()
```
  - getK
```
public static int getK()
```
  - docConcentration
```
public static final DoubleArrayParam docConcentration()
```
  - getDocConcentration
```
public static double[] getDocConcentration()
```
  - topicConcentration
```
public static final DoubleParam topicConcentration()
```
  - getTopicConcentration
```
public static double getTopicConcentration()
```
  - supportedOptimizers
```
public static final String[] supportedOptimizers()
```
  - optimizer
```
public static final Param<String> optimizer()
```
  - getOptimizer
```
public static String getOptimizer()
```
  - topicDistributionCol
```
public static final Param<String> topicDistributionCol()
```
  - getTopicDistributionCol
```
public static String getTopicDistributionCol()
```
  - learningOffset
```
public static final DoubleParam learningOffset()
```
  - getLearningOffset
```
public static double getLearningOffset()
```
  - learningDecay
```
public static final DoubleParam learningDecay()
```
  - getLearningDecay
```
public static double getLearningDecay()
```
  - subsamplingRate
```
public static final DoubleParam subsamplingRate()
```
  - getSubsamplingRate
```
public static double getSubsamplingRate()
```
  - optimizeDocConcentration
```
public static final BooleanParam optimizeDocConcentration()
```
  - getOptimizeDocConcentration
```
public static boolean getOptimizeDocConcentration()
```
  - keepLastCheckpoint
```
public static final BooleanParam keepLastCheckpoint()
```
  - getKeepLastCheckpoint
```
public static boolean getKeepLastCheckpoint()
```
  - save
```
public static void save(String path)
                 throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - uid
```
public static String uid()
```
  - vocabSize
```
public static int vocabSize()
```
  - setFeaturesCol
```
public static LDAModel setFeaturesCol(String value)
```
  - setSeed
```
public static LDAModel setSeed(long value)
```
  - transform
```
public static Dataset<Row> transform(Dataset<?> dataset)
```
  - transformSchema
```
public static StructType transformSchema(StructType schema)
```
  - estimatedDocConcentration
```
public static Vector estimatedDocConcentration()
```
  - topicsMatrix
```
public static Matrix topicsMatrix()
```
  - logLikelihood
```
public static double logLikelihood(Dataset<?> dataset)
```
  - logPerplexity
```
public static double logPerplexity(Dataset<?> dataset)
```
  - describeTopics
```
public static Dataset<Row> describeTopics(int maxTermsPerTopic)
```
  - describeTopics
```
public static Dataset<Row> describeTopics()
```
  - toLocal
```
public LocalLDAModel toLocal()
```
    Convert this distributed model to a local representation. This discards info about the training dataset.
    WARNING: This involves collecting a large topicsMatrix to the driver.
    
    Returns:
    (undocumented)
  - copy
```
public DistributedLDAModel copy(ParamMap extra)
```
    Description copied from interface: Params
    
    Creates a copy of this instance with the same UID and some extra params. Subclasses should implement this method and set the return type properly. See defaultCopy().
    
    Specified by:
    
    copy in interface Params
    
    Specified by:
    
    copy in class Model<LDAModel>
    
    Parameters:
    extra - (undocumented)
    
    Returns:
    (undocumented)
  - isDistributed
```
public boolean isDistributed()
```
    Description copied from class: LDAModel
    
    Indicates whether this instance is of type DistributedLDAModel
    
    Specified by:
    
    isDistributed in class LDAModel
  - trainingLogLikelihood
```
public double trainingLogLikelihood()
```
    Log likelihood of the observed tokens in the training set, given the current parameter estimates: log P(docs | topics, topic distributions for docs, Dirichlet hyperparameters)
    Notes: - This excludes the prior; for that, use logPrior. - Even with logPrior, this is NOT the same as the data log likelihood given the hyperparameters. - This is computed from the topic distributions computed during training. If you call logLikelihood() on the same training dataset, the topic distributions will be computed again, possibly giving different results.
    
    Returns:
    (undocumented)
  - logPrior
```
public double logPrior()
```
    Log probability of the current parameter estimate: log P(topics, topic distributions for docs | Dirichlet hyperparameters)
    
    Returns:
    (undocumented)
  - getCheckpointFiles
```
public String[] getCheckpointFiles()
```
    :: DeveloperApi ::
    If using checkpointing and LDA.keepLastCheckpoint is set to true, then there may be saved checkpoint files. This method is provided so that users can manage those files.
    Note that removing the checkpoints can cause failures if a partition is lost and is needed by certain DistributedLDAModel methods. Reference counting will clean up the checkpoints when this model and derivative data go out of scope.
    
    Returns:
    Checkpoint files from training
  - deleteCheckpointFiles
```
public void deleteCheckpointFiles()
```
    :: DeveloperApi ::
    Remove any remaining checkpoint files from training.
    
    See Also:
    getCheckpointFiles
  - write
```
public MLWriter write()
```
    Description copied from interface: MLWritable
    
    Returns an MLWriter instance for this ML instance.
    
    Returns:
    (undocumented)
  - k
```
public IntParam k()
```
    Param for the number of topics (clusters) to infer. Must be > 1. Default: 10.
    
    Returns:
    (undocumented)
  - getK
```
public int getK()
```
  - docConcentration
```
public DoubleArrayParam docConcentration()
```
    Concentration parameter (commonly named "alpha") for the prior placed on documents' distributions over topics ("theta").
    This is the parameter to a Dirichlet distribution, where larger values mean more smoothing (more regularization).
    If not set by the user, then docConcentration is set automatically. If set to singleton vector [alpha], then alpha is replicated to a vector of length k in fitting. Otherwise, the docConcentration vector must be length k. (default = automatic)
    Optimizer-specific parameter settings: - EM - Currently only supports symmetric distributions, so all values in the vector should be the same. - Values should be > 1.0 - default = uniformly (50 / k) + 1, where 50/k is common in LDA libraries and +1 follows from Asuncion et al. (2009), who recommend a +1 adjustment for EM. - Online - Values should be >= 0 - default = uniformly (1.0 / k), following the implementation from https://github.com/Blei-Lab/onlineldavb.
    
    Returns:
    (undocumented)
  - getDocConcentration
```
public double[] getDocConcentration()
```
  - getOldDocConcentration
```
public Vector getOldDocConcentration()
```
    Get docConcentration used by spark.mllib LDA
  - topicConcentration
```
public DoubleParam topicConcentration()
```
    Concentration parameter (commonly named "beta" or "eta") for the prior placed on topics' distributions over terms.
    This is the parameter to a symmetric Dirichlet distribution.
    Note: The topics' distributions over terms are called "beta" in the original LDA paper by Blei et al., but are called "phi" in many later papers such as Asuncion et al., 2009.
    If not set by the user, then topicConcentration is set automatically. (default = automatic)
    Optimizer-specific parameter settings: - EM - Value should be > 1.0 - default = 0.1 + 1, where 0.1 gives a small amount of smoothing and +1 follows Asuncion et al. (2009), who recommend a +1 adjustment for EM. - Online - Value should be >= 0 - default = (1.0 / k), following the implementation from https://github.com/Blei-Lab/onlineldavb.
    
    Returns:
    (undocumented)
  - getTopicConcentration
```
public double getTopicConcentration()
```
  - getOldTopicConcentration
```
public double getOldTopicConcentration()
```
    Get topicConcentration used by spark.mllib LDA
  - supportedOptimizers
```
public String[] supportedOptimizers()
```
    Supported values for Param optimizer.
  - optimizer
```
public Param<String> optimizer()
```
    Optimizer or inference algorithm used to estimate the LDA model. Currently supported (case-insensitive): - "online": Online Variational Bayes (default) - "em": Expectation-Maximization
    For details, see the following papers: - Online LDA: Hoffman, Blei and Bach. "Online Learning for Latent Dirichlet Allocation." Neural Information Processing Systems, 2010. http://www.cs.columbia.edu/~blei/papers/HoffmanBleiBach2010b.pdf - EM: Asuncion et al. "On Smoothing and Inference for Topic Models." Uncertainty in Artificial Intelligence, 2009. http://arxiv.org/pdf/1205.2662.pdf
    
    Returns:
    (undocumented)
  - getOptimizer
```
public String getOptimizer()
```
  - topicDistributionCol
```
public Param<String> topicDistributionCol()
```
    Output column with estimates of the topic mixture distribution for each document (often called "theta" in the literature). Returns a vector of zeros for an empty document.
    This uses a variational approximation following Hoffman et al. (2010), where the approximate distribution is called "gamma." Technically, this method returns this approximation "gamma" for each document.
    
    Returns:
    (undocumented)
  - getTopicDistributionCol
```
public String getTopicDistributionCol()
```
  - learningOffset
```
public DoubleParam learningOffset()
```
    For Online optimizer only: optimizer = "online".
    A (positive) learning parameter that downweights early iterations. Larger values make early iterations count less. This is called "tau0" in the Online LDA paper (Hoffman et al., 2010) Default: 1024, following Hoffman et al.
    
    Returns:
    (undocumented)
  - getLearningOffset
```
public double getLearningOffset()
```
  - learningDecay
```
public DoubleParam learningDecay()
```
    For Online optimizer only: optimizer = "online".
    Learning rate, set as an exponential decay rate. This should be between (0.5, 1.0] to guarantee asymptotic convergence. This is called "kappa" in the Online LDA paper (Hoffman et al., 2010). Default: 0.51, based on Hoffman et al.
    
    Returns:
    (undocumented)
  - getLearningDecay
```
public double getLearningDecay()
```
  - subsamplingRate
```
public DoubleParam subsamplingRate()
```
    For Online optimizer only: optimizer = "online".
    Fraction of the corpus to be sampled and used in each iteration of mini-batch gradient descent, in range (0, 1].
    Note that this should be adjusted in synch with LDA.maxIter so the entire corpus is used. Specifically, set both so that maxIterations * miniBatchFraction >= 1.
    Note: This is the same as the miniBatchFraction parameter in OnlineLDAOptimizer.
    Default: 0.05, i.e., 5% of total documents.
    
    Returns:
    (undocumented)
  - getSubsamplingRate
```
public double getSubsamplingRate()
```
  - optimizeDocConcentration
```
public BooleanParam optimizeDocConcentration()
```
    For Online optimizer only (currently): optimizer = "online".
    Indicates whether the docConcentration (Dirichlet parameter for document-topic distribution) will be optimized during training. Setting this to true will make the model more expressive and fit the training data better. Default: false
    
    Returns:
    (undocumented)
  - getOptimizeDocConcentration
```
public boolean getOptimizeDocConcentration()
```
  - keepLastCheckpoint
```
public BooleanParam keepLastCheckpoint()
```
    For EM optimizer only: optimizer = "em".
    If using checkpointing, this indicates whether to keep the last checkpoint. If false, then the checkpoint will be deleted. Deleting the checkpoint can cause failures if a data partition is lost, so set this bit with care. Note that checkpoints will be cleaned up via reference counting, regardless.
    See DistributedLDAModel.getCheckpointFiles for getting remaining checkpoints and DistributedLDAModel.deleteCheckpointFiles for removing remaining checkpoints.
    Default: true
    
    Returns:
    (undocumented)
  - getKeepLastCheckpoint
```
public boolean getKeepLastCheckpoint()
```
  - validateAndTransformSchema
```
public StructType validateAndTransformSchema(StructType schema)
```
    Validates and transforms the input schema.
    
    Parameters:
    schema - input schema
    
    Returns:
    output schema
  - getOldOptimizer
```
public LDAOptimizer getOldOptimizer()
```
  - featuresCol
```
public Param<String> featuresCol()
```
    Param for features column name.
    
    Returns:
    (undocumented)
  - getFeaturesCol
```
public String getFeaturesCol()
```
  - maxIter
```
public IntParam maxIter()
```
    Param for maximum number of iterations (>= 0).
    
    Returns:
    (undocumented)
  - getMaxIter
```
public int getMaxIter()
```
  - seed
```
public LongParam seed()
```
    Param for random seed.
    
    Returns:
    (undocumented)
  - getSeed
```
public long getSeed()
```
  - checkpointInterval
```
public IntParam checkpointInterval()
```
    Param for set checkpoint interval (>= 1) or disable checkpoint (-1). E.g. 10 means that the cache will get checkpointed every 10 iterations.
    
    Returns:
    (undocumented)
  - getCheckpointInterval
```
public int getCheckpointInterval()
```

Class DistributedLDAModel

Method Summary

Methods inherited from class org.apache.spark.ml.clustering.LDAModel

Methods inherited from class org.apache.spark.ml.Model

Methods inherited from class org.apache.spark.ml.Transformer

Methods inherited from class Object

Methods inherited from interface org.apache.spark.ml.param.Params

Methods inherited from interface org.apache.spark.ml.util.Identifiable

Methods inherited from interface org.apache.spark.ml.util.MLWritable

Method Detail

read

load

toString

params

validateParams

explainParam

explainParams

isSet

isDefined

hasParam

getParam

set

get

clear

getOrDefault

getDefault

hasDefault

extractParamMap

extractParamMap

transform

transform

transform

parent

parent_$eq

setParent

hasParent

featuresCol

getFeaturesCol

maxIter

getMaxIter

seed

getSeed

checkpointInterval

getCheckpointInterval

k

getK

docConcentration

getDocConcentration

topicConcentration

getTopicConcentration

supportedOptimizers

optimizer

getOptimizer

topicDistributionCol

getTopicDistributionCol

learningOffset

getLearningOffset

learningDecay

getLearningDecay

subsamplingRate

getSubsamplingRate

optimizeDocConcentration

getOptimizeDocConcentration

keepLastCheckpoint

getKeepLastCheckpoint

save

uid

vocabSize

setFeaturesCol

setSeed

transform

transformSchema

estimatedDocConcentration

topicsMatrix

logLikelihood

logPerplexity

describeTopics

describeTopics

toLocal

copy