atlas::descents::DescentStatus Class Reference

Describes the descent status of each simple root for a single representation. More...

#include <descents.h>

List of all members.

Public Types
enum	Value {   ComplexAscent, RealNonparity, ImaginaryTypeI, ImaginaryTypeII,   ImaginaryCompact, ComplexDescent, RealTypeII, RealTypeI }
Public Member Functions
	DescentStatus ()
	~DescentStatus ()
	DescentStatus (const DescentStatus &ds)
DescentStatus &	operator= (const DescentStatus &ds)
Value	operator[] (size_t s) const
	Returns descent status of simple root #s.
void	set (size_t s, Value v)
	Sets the descent status of simple root #s to v.
Static Public Member Functions
bool	isDescent (Value v)
	Tests whether Value is 4 through 7. These are the descents.
bool	isDirectRecursion (Value v)
	Tests whether both bits of DirectRecursionMask are set.
Private Attributes
unsigned char	d_data [constants::RANK_MAX]
	Value of byte #j specifies the descent status of simple root #j.
Static Private Attributes
const unsigned	ValMask = constants::charBits - 1
const unsigned	DescentMask = 0x4ul
	Bitwise "and" of Value with this is non-zero if Value is one of ImaginaryCompact, ComplexDescent, RealTypeII, or RealTypeI (numbers 4--7).
const unsigned	DirectRecursionMask = 0x5ul
	Bitwise "and" of Value with this is equal to this if Value is either ComplexDescent (5) or RealTypeI (7).

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Detailed Description

Describes the descent status of each simple root for a single representation.

There are eight possibilities for the descent status of a representation parameter w.r.t. a simple reflection, so this information could be packed in three bits. However, this would lead to having some packets lie across word boundaries, with the ensuing complications. Four bits is a good choice; here we take the lazy way of using even eight bits, as this makes the reading even a bit easier. We might come back to four at some later change---this should not require a change in user interface.

Definition at line 47 of file descents.h.

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Member Enumeration Documentation

enum atlas::descents::DescentStatus::Value

Enumeration values: ComplexAscent  RealNonparity  ImaginaryTypeI  ImaginaryTypeII  ImaginaryCompact  ComplexDescent  RealTypeII  RealTypeI  Definition at line 75 of file descents.h.

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Constructor & Destructor Documentation

atlas::descents::DescentStatus::DescentStatus (   )  [inline]

Definition at line 99 of file descents.h.

atlas::descents::DescentStatus::~DescentStatus (   )  [inline]

Definition at line 103 of file descents.h.

atlas::descents::DescentStatus::DescentStatus (  const DescentStatus &  ds  )  [inline]

Definition at line 106 of file descents.h. References d_data.

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Member Function Documentation

bool atlas::descents::DescentStatus::isDescent (  Value  v  )  [inline, static]

Tests whether Value is 4 through 7. These are the descents. The simple roots passing this test comprise the tau invariant for the representation. Definition at line 84 of file descents.h.

bool atlas::descents::DescentStatus::isDirectRecursion (  Value  v  )  [inline, static]

Tests whether both bits of DirectRecursionMask are set. In the case of a complex descent or a real type I descent there is a simple recursion formula for the KL element. Definition at line 94 of file descents.h.

DescentStatus& atlas::descents::DescentStatus::operator= (  const DescentStatus &  ds  )  [inline]

Definition at line 110 of file descents.h. References d_data.

Value atlas::descents::DescentStatus::operator[] (  size_t  s  )  const [inline]

Returns descent status of simple root #s. Definition at line 120 of file descents.h.

void atlas::descents::DescentStatus::set (  size_t  s, Value  v )  [inline]

Sets the descent status of simple root #s to v. Definition at line 129 of file descents.h. Referenced by atlas::blocks::descents(), and atlas::klsupport::KLSupport::fillDownsets().

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Member Data Documentation

unsigned char atlas::descents::DescentStatus::d_data[constants::RANK_MAX] [private]

Value of byte #j specifies the descent status of simple root #j. Value should be 0 through 7; values 0 through 3 are ascents, and 4 through 7 are descents. Definition at line 58 of file descents.h. Referenced by DescentStatus(), and operator=().

const unsigned atlas::descents::DescentStatus::DescentMask = 0x4ul [static, private]

Bitwise "and" of Value with this is non-zero if Value is one of ImaginaryCompact, ComplexDescent, RealTypeII, or RealTypeI (numbers 4--7). Definition at line 65 of file descents.h.

const unsigned atlas::descents::DescentStatus::DirectRecursionMask = 0x5ul [static, private]

Bitwise "and" of Value with this is equal to this if Value is either ComplexDescent (5) or RealTypeI (7). Definition at line 71 of file descents.h.

const unsigned atlas::descents::DescentStatus::ValMask = constants::charBits - 1 [static, private]

Definition at line 59 of file descents.h.

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The documentation for this class was generated from the following file:

• /home/r0/dav/atlas.dir/atlas3/sources/gkmod/descents.h

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