npstat::ArrayNDScanner Class Reference

#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().

            {initialize(shape, lenShape);}

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

inlineexplicit

Definition at line 44 of file ArrayNDScanner.h.

References initialize().

            {initialize(shape.empty() ? static_cast<unsigned*>(0) : 
                        &shape[0], shape.size());}

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_.

{return dim_;}

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];
    }

bool npstat::ArrayNDScanner::isValid ( void  ) const

inline

Returns false when iteration is complete

Definition at line 59 of file ArrayNDScanner.h.

References maxState_, and state_.

Referenced by npstat::LinInterpolatedTableND< Numeric, Axis >::invertRatioResponse(), npstat::LinInterpolatedTableND< Numeric, Axis >::invertWRTAxis(), and core.AutoHandle.AutoHandle::ReallyLoad().

{return state_ < maxState_;}

unsigned long npstat::ArrayNDScanner::maxState ( ) const

inline

Maximum possible state (i.e., linear index of the scan)

Definition at line 56 of file ArrayNDScanner.h.

References maxState_.

{return maxState_;}

ArrayNDScanner& npstat::ArrayNDScanner::operator++ ( void  )

inline

Prefix increment

Definition at line 68 of file ArrayNDScanner.h.

References maxState_, and state_.

            {if (state_ < maxState_) ++state_; return *this;}

void npstat::ArrayNDScanner::operator++ ( int  )

inline

Postfix increment (distinguished by the dummy "int" parameter)

Definition at line 72 of file ArrayNDScanner.h.

References maxState_, and state_.

{if (state_ < maxState_) ++state_;}

void npstat::ArrayNDScanner::reset ( void  )

inline

Reset the state (as if the object has just been constructed)

Definition at line 65 of file ArrayNDScanner.h.

References state_.

{state_ = 0UL;}

void npstat::ArrayNDScanner::setState ( const unsigned long  state )

inline

Set the state directly

Definition at line 75 of file ArrayNDScanner.h.

References maxState_, and state_.

            {state_ = state <= maxState_ ? state : maxState_;}

unsigned long npstat::ArrayNDScanner::state ( ) const

inline

Retrieve current state (i.e., linear index of the scan)

Definition at line 53 of file ArrayNDScanner.h.

References state_.

{return state_;}

Member Data Documentation

unsigned npstat::ArrayNDScanner::dim_

private

Definition at line 86 of file ArrayNDScanner.h.

Referenced by dim(), getIndex(), and initialize().

unsigned long npstat::ArrayNDScanner::maxState_

private

Definition at line 85 of file ArrayNDScanner.h.

Referenced by getIndex(), initialize(), isValid(), maxState(), operator++(), and setState().

unsigned long npstat::ArrayNDScanner::state_

private

Definition at line 84 of file ArrayNDScanner.h.

Referenced by getIndex(), initialize(), isValid(), operator++(), reset(), setState(), and state().

unsigned long npstat::ArrayNDScanner::strides_[CHAR_BIT *sizeof(unsigned long)]

private

Definition at line 83 of file ArrayNDScanner.h.

Referenced by getIndex(), and initialize().