cusp::identity_operator< ValueType, MemorySpace, IndexType > Class Template Reference

#include <linear_operator.h>

Inheritance diagram for cusp::identity_operator< ValueType, MemorySpace, IndexType >:

Public Methods
	identity_operator (void)
	identity_operator (IndexType num_rows, IndexType num_cols)
template<typename DerivedPolicy , typename VectorType1 , typename VectorType2 >
void	operator() (thrust::execution_policy< DerivedPolicy > &exec, const VectorType1 &x, VectorType2 &y) const
	Apply the identity operator to vector x using an explicit execution policy.
template<typename VectorType1 , typename VectorType2 >
void	operator() (const VectorType1 &x, VectorType2 &y) const
Public Methods inherited from cusp::linear_operator< ValueType, MemorySpace, IndexType >
	linear_operator (void)
	linear_operator (IndexType num_rows, IndexType num_cols)
	linear_operator (IndexType num_rows, IndexType num_cols, IndexType num_entries)

Detailed description

template<typename ValueType, typename MemorySpace, typename IndexType = int>
class cusp::identity_operator< ValueType, MemorySpace, IndexType >

Simple identity operator.

Template Parameters

IndexType	Type used for operator indices (e.g. int).
ValueType	Type used for operator values (e.g. float).
MemorySpace	A memory space (e.g. cusp::host_memory or cusp::device_memory)

Overview

A linear operator that copies the input vector to the output vector unchanged. Corresponds to the identity matrix (I).

Example

The following code snippet demonstrates using the identity operator.

// include linear_operator header file
#include <cusp/linear_operator.h>
#include <cusp/print.h>
 
int main(void)
{
  // number of entries
  const int N = 4;
 
  // construct instance of identity operator
  cusp::identity_operator A(N);
 
  // initialize x and y vectors
  cusp::array1d<float, cusp::device_memory> x(A.num_rows, 1);
  cusp::array1d<float, cusp::device_memory> y(A.num_rows, 0);
 
  // call operator()(x,y) through multiply interface
  A(x,y);
 
  // print the transformed vector
  cusp::print(y);
}

Definition at line 183 of file linear_operator.h.

Constructor & Destructor Documentation

identity_operator() [1/2]

template<typename ValueType , typename MemorySpace , typename IndexType = int>

cusp::identity_operator< ValueType, MemorySpace, IndexType >::identity_operator ( void  )

inline

Construct an empty identity_operator.

Definition at line 193 of file linear_operator.h.

identity_operator() [2/2]

template<typename ValueType , typename MemorySpace , typename IndexType = int>

cusp::identity_operator< ValueType, MemorySpace, IndexType >::identity_operator ( IndexType  num_rows, IndexType  num_cols  )

inline

Construct a identity_operator with a specific shape.

Parameters

num_rows	Number of rows.
num_cols	Number of columns.

Definition at line 201 of file linear_operator.h.

Member Function Documentation

operator()() [1/2]

template<typename ValueType , typename MemorySpace , typename IndexType = int>

template<typename VectorType1 , typename VectorType2 >

void cusp::identity_operator< ValueType, MemorySpace, IndexType >::operator() ( const VectorType1 &  x, VectorType2 &  y  ) const

inline

Apply the identity_operator to vector x and produce vector y.

Template Parameters

VectorType1	Type of the input vector
VectorType2	Type of the output vector

Parameters

x	Input vector to copy.
y	Output vector to produce.

Definition at line 228 of file linear_operator.h.

operator()() [2/2]

template<typename ValueType , typename MemorySpace , typename IndexType = int>

template<typename DerivedPolicy , typename VectorType1 , typename VectorType2 >

void cusp::identity_operator< ValueType, MemorySpace, IndexType >::operator() ( thrust::execution_policy< DerivedPolicy > &  exec, const VectorType1 &  x, VectorType2 &  y  ) const

inline

Apply the identity operator to vector x using an explicit execution policy.

Template Parameters

DerivedPolicy	execution policy
VectorType1	Type of the input vector
VectorType2	Type of the output vector

Parameters

exec	the execution policy
x	input vector
y	output vector

Definition at line 214 of file linear_operator.h.