MLContext (SystemML 0.15.0 API)

java.lang.Object
- org.apache.sysml.api.mlcontext.MLContext

```
public class MLContext
extends Object
```
The MLContext API offers programmatic access to SystemML on Spark from languages such as Scala, Java, and Python.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`MLContext.ExecutionType` The different types of execution environments supported by SystemML.
`static class`	`MLContext.ExplainLevel` The different explain levels supported by SystemML.
`class`	`MLContext.InternalProxy` Used internally by MLContextProxy.

Field Summary

Fields
Modifier and Type Field and Description

protected static org.apache.log4j.Logger log
Logger for MLContext

Fields
Modifier and Type	Field and Description
`protected static org.apache.log4j.Logger`	`log` Logger for MLContext

Constructor Summary

Constructors
Constructor and Description
`MLContext(org.apache.spark.api.java.JavaSparkContext javaSparkContext)` Create an MLContext based on a JavaSparkContext for interaction with SystemML on Spark.
`MLContext(org.apache.spark.SparkContext sparkContext)` Create an MLContext based on a SparkContext for interaction with SystemML on Spark.
`MLContext(org.apache.spark.sql.SparkSession spark)` Create an MLContext based on a SparkSession for interaction with SystemML on Spark.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`String`	`buildTime()` Obtain the SystemML jar file build time.
`void`	`close()` Closes the mlcontext, which includes the cleanup of static and local state as well as scratch space and buffer pool cleanup.
`MLResults`	`execute(Script script)` Execute a DML or PYDML Script.
`MLResults`	`execute(Script script, ScriptExecutor scriptExecutor)` Execute a DML or PYDML Script object using a ScriptExecutor.
`static MLContext`	`getActiveMLContext()` Retrieve the currently active MLContext.
`MLContext.ExecutionType`	`getExecutionType()` Obtain the current execution environment.
`MLContext.InternalProxy`	`getInternalProxy()` Used internally by MLContextProxy.
`org.apache.spark.sql.SparkSession`	`getSparkSession()` Obtain the SparkSession associated with this MLContext.
`int`	`getStatisticsMaxHeavyHitters()` Obtain the maximum number of heavy hitters that are printed out as part of the statistics.
`ProjectInfo`	`info()` Obtain information about the project such as version and build time from the manifest in the SystemML jar file.
`boolean`	`isExplain()` Whether or not an explanation of the DML/PYDML program should be output to standard output.
`boolean`	`isForceGPU()` Whether or not the "force" GPU mode is enabled.
`boolean`	`isGPU()` Whether or not the GPU mode is enabled.
`boolean`	`isInitBeforeExecution()` Whether or not the default ScriptExecutor should be initialized before execution.
`boolean`	`isMaintainSymbolTable()` Obtain whether or not all values should be maintained in the symbol table after execution.
`boolean`	`isStatistics()` Whether or not statistics of the DML/PYDML program execution should be output to standard output.
`void`	`resetConfig()` Reset configuration settings to default settings.
`void`	`setConfig(String configFilePath)` Set SystemML configuration based on a configuration file.
`void`	`setConfigProperty(String propertyName, String propertyValue)` Set configuration property, such as `setConfigProperty("localtmpdir", "/tmp/systemml")`.
`void`	`setExecutionScript(Script executionScript)` Sets the script that is being executed
`void`	`setExecutionType(MLContext.ExecutionType executionType)` Set the execution environment.
`void`	`setExplain(boolean explain)` Whether or not an explanation of the DML/PYDML program should be output to standard output.
`void`	`setExplainLevel(MLContext.ExplainLevel explainLevel)` Set the level of program explanation that should be displayed if explain is set to true.
`void`	`setExplainLevel(String explainLevel)` Set the level of program explanation that should be displayed if explain is set to true.
`void`	`setForceGPU(boolean enable)` Whether or not to explicitly "force" the usage of GPU.
`void`	`setGPU(boolean enable)` Whether or not to use (an available) GPU on the driver node.
`void`	`setInitBeforeExecution(boolean initBeforeExecution)` Whether or not the default ScriptExecutor should be initialized before execution.
`void`	`setMaintainSymbolTable(boolean maintainSymbolTable)` Set whether or not all values should be maintained in the symbol table after execution.
`void`	`setStatistics(boolean statistics)` Whether or not statistics of the DML/PYDML program execution should be output to standard output.
`void`	`setStatisticsMaxHeavyHitters(int maxHeavyHitters)` Sets the maximum number of heavy hitters that are printed out as part of the statistics.
`String`	`version()` Obtain the SystemML version number.

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

- Field Detail
  - log
```
protected static org.apache.log4j.Logger log
```
    Logger for MLContext
- Constructor Detail
  - MLContext
```
public MLContext(org.apache.spark.sql.SparkSession spark)
```
    Create an MLContext based on a SparkSession for interaction with SystemML on Spark.
    
    Parameters:
    
    spark - SparkSession
  - MLContext
```
public MLContext(org.apache.spark.SparkContext sparkContext)
```
    Create an MLContext based on a SparkContext for interaction with SystemML on Spark.
    
    Parameters:
    
    sparkContext - SparkContext
  - MLContext
```
public MLContext(org.apache.spark.api.java.JavaSparkContext javaSparkContext)
```
    Create an MLContext based on a JavaSparkContext for interaction with SystemML on Spark.
    
    Parameters:
    
    javaSparkContext - JavaSparkContext
- Method Detail
  - getActiveMLContext
```
public static MLContext getActiveMLContext()
```
    Retrieve the currently active MLContext. This is used internally by SystemML via MLContextProxy.
    
    Returns:
    
    the active MLContext
  - resetConfig
```
public void resetConfig()
```
    Reset configuration settings to default settings.
  - setConfigProperty
```
public void setConfigProperty(String propertyName,
                              String propertyValue)
```
    Set configuration property, such as setConfigProperty("localtmpdir", "/tmp/systemml").
    
    Parameters:
    
    propertyName - property name
    
    propertyValue - property value
  - execute
```
public MLResults execute(Script script)
```
    Execute a DML or PYDML Script.
    
    Parameters:
    
    script - The DML or PYDML Script object to execute.
    
    Returns:
    
    the results as a MLResults object
  - execute
```
public MLResults execute(Script script,
                         ScriptExecutor scriptExecutor)
```
    Execute a DML or PYDML Script object using a ScriptExecutor. The ScriptExecutor class can be extended to allow the modification of the default execution pathway.
    
    Parameters:
    
    script - the DML or PYDML Script object
    
    scriptExecutor - the ScriptExecutor that defines the script execution pathway
    
    Returns:
    
    the results as a MLResults object
  - setExecutionScript
```
public void setExecutionScript(Script executionScript)
```
    Sets the script that is being executed
    
    Parameters:
    
    executionScript - script that is being executed
  - setConfig
```
public void setConfig(String configFilePath)
```
    Set SystemML configuration based on a configuration file.
    
    Parameters:
    
    configFilePath - path to the configuration file
  - getSparkSession
```
public org.apache.spark.sql.SparkSession getSparkSession()
```
    Obtain the SparkSession associated with this MLContext.
    
    Returns:
    
    the SparkSession associated with this MLContext.
  - isExplain
```
public boolean isExplain()
```
    Whether or not an explanation of the DML/PYDML program should be output to standard output.
    
    Returns:
    
    true if explanation should be output, false otherwise
  - setExplain
```
public void setExplain(boolean explain)
```
    Whether or not an explanation of the DML/PYDML program should be output to standard output.
    
    Parameters:
    
    explain - true if explanation should be output, false otherwise
  - isMaintainSymbolTable
```
public boolean isMaintainSymbolTable()
```
    Obtain whether or not all values should be maintained in the symbol table after execution.
    
    Returns:
    
    true if all values should be maintained in the symbol table, false otherwise
  - setMaintainSymbolTable
```
public void setMaintainSymbolTable(boolean maintainSymbolTable)
```
    Set whether or not all values should be maintained in the symbol table after execution.
    
    Parameters:
    
    maintainSymbolTable - true if all values should be maintained in the symbol table, false otherwise
  - setExplainLevel
```
public void setExplainLevel(MLContext.ExplainLevel explainLevel)
```
    Set the level of program explanation that should be displayed if explain is set to true.
    
    Parameters:
    
    explainLevel - the level of program explanation
  - setExplainLevel
```
public void setExplainLevel(String explainLevel)
```
    Set the level of program explanation that should be displayed if explain is set to true.
    
    Parameters:
    
    explainLevel - string denoting program explanation
  - setGPU
```
public void setGPU(boolean enable)
```
    Whether or not to use (an available) GPU on the driver node. If a GPU is not available, and the GPU mode is set, SystemML will crash when the program is run.
    
    Parameters:
    
    enable - true if needs to be enabled, false otherwise
  - setForceGPU
```
public void setForceGPU(boolean enable)
```
    Whether or not to explicitly "force" the usage of GPU. If a GPU is not available, and the GPU mode is set or if available memory on GPU is less, SystemML will crash when the program is run.
    
    Parameters:
    
    enable - true if needs to be enabled, false otherwise
  - isGPU
```
public boolean isGPU()
```
    Whether or not the GPU mode is enabled.
    
    Returns:
    
    true if enabled, false otherwise
  - isForceGPU
```
public boolean isForceGPU()
```
    Whether or not the "force" GPU mode is enabled.
    
    Returns:
    
    true if enabled, false otherwise
  - getInternalProxy
```
public MLContext.InternalProxy getInternalProxy()
```
    Used internally by MLContextProxy.
    
    Returns:
    
    InternalProxy object used by MLContextProxy
  - isStatistics
```
public boolean isStatistics()
```
    Whether or not statistics of the DML/PYDML program execution should be output to standard output.
    
    Returns:
    
    true if statistics should be output, false otherwise
  - setStatistics
```
public void setStatistics(boolean statistics)
```
    Whether or not statistics of the DML/PYDML program execution should be output to standard output.
    
    Parameters:
    
    statistics - true if statistics should be output, false otherwise
  - setStatisticsMaxHeavyHitters
```
public void setStatisticsMaxHeavyHitters(int maxHeavyHitters)
```
    Sets the maximum number of heavy hitters that are printed out as part of the statistics.
    
    Parameters:
    
    maxHeavyHitters - maximum number of heavy hitters to print
  - close
```
public void close()
```
    Closes the mlcontext, which includes the cleanup of static and local state as well as scratch space and buffer pool cleanup. Note that the spark context is not explicitly closed to allow external reuse.
  - info
```
public ProjectInfo info()
```
    Obtain information about the project such as version and build time from the manifest in the SystemML jar file.
    
    Returns:
    
    information about the project
  - version
```
public String version()
```
    Obtain the SystemML version number.
    
    Returns:
    
    the SystemML version number
  - buildTime
```
public String buildTime()
```
    Obtain the SystemML jar file build time.
    
    Returns:
    
    the SystemML jar file build time
  - getStatisticsMaxHeavyHitters
```
public int getStatisticsMaxHeavyHitters()
```
    Obtain the maximum number of heavy hitters that are printed out as part of the statistics.
    
    Returns:
    
    maximum number of heavy hitters to print
  - isInitBeforeExecution
```
public boolean isInitBeforeExecution()
```
    Whether or not the default ScriptExecutor should be initialized before execution.
    
    Returns:
    
    true if ScriptExecutor should be initialized before execution, false otherwise
  - setInitBeforeExecution
```
public void setInitBeforeExecution(boolean initBeforeExecution)
```
    Whether or not the default ScriptExecutor should be initialized before execution.
    
    Parameters:
    
    initBeforeExecution - true if ScriptExecutor should be initialized before execution, false otherwise
  - getExecutionType
```
public MLContext.ExecutionType getExecutionType()
```
    Obtain the current execution environment.
    
    Returns:
    
    the execution environment
  - setExecutionType
```
public void setExecutionType(MLContext.ExecutionType executionType)
```
    Set the execution environment.
    
    Parameters:
    
    executionType - the execution environment

Methods inherited from class java.lang.Object

log

MLContext

MLContext

MLContext

getActiveMLContext

resetConfig

setConfigProperty

execute

execute

setExecutionScript

setConfig

getSparkSession

isExplain

setExplain

isMaintainSymbolTable

setMaintainSymbolTable

setExplainLevel

setExplainLevel

setGPU

setForceGPU

isGPU

isForceGPU

getInternalProxy

isStatistics

setStatistics

setStatisticsMaxHeavyHitters

close

info

version

buildTime

getStatisticsMaxHeavyHitters

isInitBeforeExecution

setInitBeforeExecution

getExecutionType

setExecutionType