#include <ArrayNDScanner.h>

Public Member Functions
unsigned	dim () const

void	getIndex (unsigned *index, unsigned indexBufferLen) const

bool	isValid () const

unsigned long	maxState () const

ArrayNDScanner &	operator++ ()

void	operator++ (int)

void	reset ()

void	setState (const unsigned long state)

unsigned long	state () const


	ArrayNDScanner (const unsigned *shape, const unsigned lenShape)

	ArrayNDScanner (const std::vector< unsigned > &shape)

Private Member Functions
	ArrayNDScanner ()

void	initialize (const unsigned *shape, unsigned lenShape)

Private Attributes
unsigned	dim_

unsigned long	maxState_

unsigned long	state_

unsigned long	strides_ [CHAR_BIT *sizeof(unsigned long)]

Detailed Description

This class can be used to iterate over array indices without actually building the array or requesting any memory from the heap. Typical use:

*   for (ArrayNDScanner scanner(shape); scanner.isValid(); ++scanner)
*   {
*       scanner.getIndex(indexArray, indexArrayLen);
*       .... Do what is necessary with multidimensional index ....
*       .... Extract linear index: ...............................
*       scanner.state();
*   }
* 

This can be useful, for example, in case one needs to iterate over slices of some array (so that the array itself can not be used to obtain similar information easily).

Definition at line 36 of file ArrayNDScanner.h.

Constructor & Destructor Documentation

npstat::ArrayNDScanner::ArrayNDScanner	(	const unsigned *	shape,
		const unsigned	lenShape
	)

inline

Constructor from a multidimensional array shape

Definition at line 41 of file ArrayNDScanner.h.

References initialize().

42 {initialize(shape, lenShape);}

npstat::ArrayNDScanner::initialize

void initialize(const unsigned *shape, unsigned lenShape)

Definition: ArrayNDScanner.cc:7

npstat::ArrayNDScanner::ArrayNDScanner ( const std::vector< unsigned > & shape )

inlineexplicit

Definition at line 44 of file ArrayNDScanner.h.

References initialize().

45 {initialize(shape.empty() ? static_cast<unsigned*>(0) :

46 &shape[0], shape.size());}

npstat::ArrayNDScanner::initialize

void initialize(const unsigned *shape, unsigned lenShape)

Definition: ArrayNDScanner.cc:7

npstat::ArrayNDScanner::ArrayNDScanner ( )

private

Member Function Documentation

unsigned npstat::ArrayNDScanner::dim ( ) const

inline

Dimensionality of the scan

Definition at line 50 of file ArrayNDScanner.h.

References dim_.

50 {return dim_;}

npstat::ArrayNDScanner::dim_

unsigned dim_

Definition: ArrayNDScanner.h:86

void npstat::ArrayNDScanner::getIndex	(	unsigned *	index,
		unsigned	indexBufferLen
	)		const

Retrieve current multidimensional index

Definition at line 29 of file ArrayNDScanner.cc.

References assert(), dim_, i, customizeTrackingMonitorSeedNumber::idx, cmsLHEtoEOSManager::l, maxState_, state_, and strides_.

     {
         if (indexBufferLen < dim_) throw npstat::NpstatInvalidArgument(
             "In npstat::ArrayNDScanner::getIndex: "
             "insufficient length of the output buffer");
         if (state_ >= maxState_) throw npstat::NpstatRuntimeError(
             "In npstat::ArrayNDScanner::getIndex: invalid scanner state");
         assert(ix);
 
         unsigned long l = state_;
         for (unsigned i=0; i<dim_; ++i)
         {
             unsigned long idx = l / strides_[i];
             ix[i] = static_cast<unsigned>(idx);
             l -= (idx * strides_[i]);
         }
     }

void npstat::ArrayNDScanner::initialize	(	const unsigned *	shape,
		unsigned	lenShape
	)

private

Definition at line 7 of file ArrayNDScanner.cc.

References assert(), dim_, j, maxState_, state_, and strides_.

Referenced by ArrayNDScanner().

     {
         // Check argument validity
         if (lenShape == 0U || lenShape >= CHAR_BIT*sizeof(unsigned long))
             throw npstat::NpstatInvalidArgument(
                 "In npstat::ArrayNDScanner::initialize: invalid scan shape");
         assert(shape);
         for (unsigned j=0; j<lenShape; ++j)
             if (!shape[j]) throw npstat::NpstatInvalidArgument(
                 "In npstat::ArrayNDScanner::initialize: "
                 "number of scans must be positive in each dimension");
 
         // Initialize the scanner data
         state_ = 0UL;
         dim_ = lenShape;
         strides_[dim_ - 1] = 1UL;
         for (unsigned j=dim_ - 1; j>0; --j)
             strides_[j - 1] = strides_[j]*shape[j];
         maxState_ = strides_[0]*shape[0];
     }