CompressionElement Class Reference

#include <CovarianceParameterization.h>

Public Types
enum	Method {   float16 = 0, reduceMantissa = 1, logPack = 2, tanLogPack = 3,   zero = 4, one = 5 }
enum	Target { realValue = 0, ratioToRef = 1, differenceToRef = 2 }

Public Member Functions
	CompressionElement ()
	CompressionElement (Method m, Target t, int bitsUsed, std::vector< float > p)
uint16_t	pack (float value, float ref=0.) const
float	unpack (uint16_t packed, float ref=0.) const

Public Attributes
int	bits
Method	method
std::vector< float >	params
Target	target

Detailed Description

Definition at line 9 of file CovarianceParameterization.h.

Member Enumeration Documentation

Method

enum CompressionElement::Method

Enumerator
float16
reduceMantissa
logPack
tanLogPack
zero
one

Definition at line 11 of file CovarianceParameterization.h.

{ float16 = 0, reduceMantissa = 1, logPack = 2, tanLogPack = 3, zero = 4, one = 5 };

Target

enum CompressionElement::Target

Enumerator
realValue
ratioToRef
differenceToRef

Definition at line 12 of file CovarianceParameterization.h.

{ realValue = 0, ratioToRef = 1, differenceToRef = 2 };

Constructor & Destructor Documentation

CompressionElement() [1/2]

CompressionElement::CompressionElement ( )

inline

Definition at line 13 of file CovarianceParameterization.h.

: method(zero), target(realValue) {}

CompressionElement() [2/2]

CompressionElement::CompressionElement ( Method  m, Target  t, int  bitsUsed, std::vector< float >  p  )

inline

Definition at line 14 of file CovarianceParameterization.h.

      : method(m), target(t), bits(bitsUsed), params(p) {}

Member Function Documentation

pack()

uint16_t CompressionElement::pack	(	float	value,
		float	ref = 0.
	)		const

Definition at line 14 of file CovarianceParameterization.cc.

                                                              {
  float toCompress = 0;
  switch (target) {
    case (realValue):
      toCompress = value;
      break;
    case (ratioToRef):
      toCompress = value / ref;
      break;
    case (differenceToRef):
      toCompress = value - ref;
      break;
  }
  switch (method) {
    case (float16):
      return MiniFloatConverter::float32to16(toCompress * params[0]);
      break;
    case (reduceMantissa):
      return MiniFloatConverter::reduceMantissaToNbits(toCompress, params[0]);
      break;
    case (zero):
      return 0;
      break;
    case (one):
      return 1.0;
      break;
    case (tanLogPack):
      return 0;  //FIXME: should be implemented
      break;
    case (logPack):
      int16_t r = logintpack::pack16log(toCompress, params[0], params[1], bits);
      return *reinterpret_cast<uint16_t *>(&r);
      break;
  }
  return 0;
}

References bits, differenceToRef, float16, MiniFloatConverter::float32to16(), logPack, method, one, logintpack::pack16log(), params, alignCSCRings::r, ratioToRef, realValue, reduceMantissa, MiniFloatConverter::reduceMantissaToNbits(), tanLogPack, target, relativeConstraints::value, and zero.

unpack()

float CompressionElement::unpack	(	uint16_t	packed,
		float	ref = 0.
	)		const

Definition at line 50 of file CovarianceParameterization.cc.

                                                                 {
  float unpacked = 0;
  switch (method) {
    case (float16):
      unpacked = MiniFloatConverter::float16to32(packed) / params[0];
      break;
    case (reduceMantissa):
      unpacked = packed;
      break;
    case (logPack):
      unpacked = logintpack::unpack16log(*reinterpret_cast<int16_t *>(&packed), params[0], params[1], bits);
      break;
    case (zero):
      unpacked = 0;
      break;
    case (one):
    case (tanLogPack):
      unpacked = 1;  //FIXME: should be implemented
  }
  switch (target) {
    case (realValue):
      return unpacked;
    case (ratioToRef):
      return unpacked * ref;
    case (differenceToRef):
      return unpacked + ref;
  }
 
  return ref;
}

References bits, differenceToRef, float16, MiniFloatConverter::float16to32(), logPack, method, one, params, ratioToRef, realValue, reduceMantissa, tanLogPack, target, logintpack::unpack16log(), and zero.

Member Data Documentation

bits

int CompressionElement::bits

Definition at line 18 of file CovarianceParameterization.h.

Referenced by pack(), and unpack().

method

Method CompressionElement::method

Definition at line 16 of file CovarianceParameterization.h.

Referenced by pack(), and unpack().

params

std::vector<float> CompressionElement::params

Definition at line 19 of file CovarianceParameterization.h.

Referenced by pack(), and unpack().

target

Target CompressionElement::target

Definition at line 17 of file CovarianceParameterization.h.

Referenced by pack(), and unpack().