Nd4jBackend

java.lang.Object
- org.nd4j.linalg.factory.Nd4jBackend

Direct Known Subclasses:

CpuBackend, JCublasBackend
```
public abstract class Nd4jBackend
extends java.lang.Object
```
An ND4j backend. A "backend" is also described here: http://nd4j.org/backend.html A backend also has 2 variables to be aware of. 1 is the environment variable, ND4J_DYNAMIC_LOAD_CLASSPATH This will define a uri path separated by ; where jars will be loaded from the path and dynamically loaded. The other is the system property: org.nd4j.backend.dynamicbackend This has the same use case but is for system properties. Of note here is that the system property takes loading precedence over the environment variable. If you want to just use the environment variable, don't define the system property. Both of these variables are for dynamically loading a backend relative to a path. The main idea here is for distributed environments like spark where you have multiple worker nodes with some having gpus and others not. When you define an environment variable on the server, you can have a hardware jar file load with respect to the node nd4j is installed on. The system property is mainly for flexibility and probably shouldn't be used in practice.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class Nd4jBackend.NoAvailableBackendException

Nested Classes
Modifier and Type	Class and Description
`static class`	`Nd4jBackend.NoAvailableBackendException`

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`BACKEND_PRIORITY_CPU`
`static int`	`BACKEND_PRIORITY_GPU`
`static java.lang.String`	`DYNAMIC_LOAD_CLASSPATH` Deprecated. Use `ND4JEnvironmentVars.BACKEND_DYNAMIC_LOAD_CLASSPATH`
`static java.lang.String`	`DYNAMIC_LOAD_CLASSPATH_PROPERTY` Deprecated. Use `ND4JSystemProperties.DYNAMIC_LOAD_CLASSPATH_PROPERTY`

Constructor Summary

Constructors
Constructor and Description

Nd4jBackend()

Constructors
Constructor and Description
`Nd4jBackend()`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`abstract boolean`	`allowsOrder()` Returns true if the backend allows order to be specified on blas operations (cblas)
`abstract boolean`	`canRun()` Returns true if the backend can run on the os or not
`abstract Resource`	`getConfigurationResource()` Get the configuration resource
`Nd4jContext`	`getContext()`
`abstract java.lang.Class`	`getNDArrayClass()` Get the actual (concrete/implementation) class for standard INDArrays for this backend
`abstract int`	`getPriority()` Gets a priority number for the backend.
`java.util.Properties`	`getProperties()`
`abstract boolean`	`isAvailable()` Determines whether a given backend is available in the current environment.
`static Nd4jBackend`	`load()` Loads the best available backend.
`static void`	`loadLibrary(java.io.File jar)` Adds the supplied Java Archive library to java.class.path.
`java.lang.String`	`toString()`

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

- Field Detail
  - BACKEND_PRIORITY_CPU
```
public static final int BACKEND_PRIORITY_CPU
```
  - BACKEND_PRIORITY_GPU
```
public static final int BACKEND_PRIORITY_GPU
```
  - DYNAMIC_LOAD_CLASSPATH
```
@Deprecated
public static final java.lang.String DYNAMIC_LOAD_CLASSPATH
```
    Deprecated. Use ND4JEnvironmentVars.BACKEND_DYNAMIC_LOAD_CLASSPATH
    
    See Also:
    
    Constant Field Values
  - DYNAMIC_LOAD_CLASSPATH_PROPERTY
```
@Deprecated
public static final java.lang.String DYNAMIC_LOAD_CLASSPATH_PROPERTY
```
    Deprecated. Use ND4JSystemProperties.DYNAMIC_LOAD_CLASSPATH_PROPERTY
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Nd4jBackend
```
public Nd4jBackend()
```
- Method Detail
  - allowsOrder
```
public abstract boolean allowsOrder()
```
    Returns true if the backend allows order to be specified on blas operations (cblas)
    
    Returns:
    
    true if the backend allows order to be specified on blas operations
  - getPriority
```
public abstract int getPriority()
```
    Gets a priority number for the backend. Backends are loaded in priority order (highest first).
    
    Returns:
    
    a priority number.
  - isAvailable
```
public abstract boolean isAvailable()
```
    Determines whether a given backend is available in the current environment.
    
    Returns:
    
    true if the backend is available; false otherwise.
  - canRun
```
public abstract boolean canRun()
```
    Returns true if the backend can run on the os or not
    
    Returns:
  - getConfigurationResource
```
public abstract Resource getConfigurationResource()
```
    Get the configuration resource
    
    Returns:
  - getNDArrayClass
```
public abstract java.lang.Class getNDArrayClass()
```
    Get the actual (concrete/implementation) class for standard INDArrays for this backend
  - load
```
public static Nd4jBackend load()
                        throws Nd4jBackend.NoAvailableBackendException
```
    Loads the best available backend.
    
    Returns:
    
    Throws:
    
    Nd4jBackend.NoAvailableBackendException
  - loadLibrary
```
public static void loadLibrary(java.io.File jar)
                        throws Nd4jBackend.NoAvailableBackendException
```
    Adds the supplied Java Archive library to java.class.path. This is benign if the library is already loaded.
    
    Parameters:
    
    jar - the jar file to add
    
    Throws:
    
    Nd4jBackend.NoAvailableBackendException
  - getProperties
```
public java.util.Properties getProperties()
                                   throws java.io.IOException
```
    Returns:
    
    Throws:
    
    java.io.IOException
  - getContext
```
public Nd4jContext getContext()
                       throws java.io.IOException
```
    Returns:
    
    Throws:
    
    java.io.IOException
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class Nd4jBackend

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

BACKEND_PRIORITY_CPU

BACKEND_PRIORITY_GPU

DYNAMIC_LOAD_CLASSPATH

DYNAMIC_LOAD_CLASSPATH_PROPERTY

Constructor Detail

Nd4jBackend

Method Detail

allowsOrder

getPriority

isAvailable

canRun

getConfigurationResource

getNDArrayClass

load

loadLibrary

getProperties

getContext

toString