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Isis::Statistics Class Reference
[Statistics]

This class is used to accumulate statistics on double arrays. More...

#include <Statistics.h>

Inherited by Isis::GaussianDistribution, Isis::GaussianStretch, and Isis::Histogram.

List of all members.

Public Member Functions

 Statistics ()
 Constructs an IsisStats object with accumulators and counters set to zero.
 ~Statistics ()
 Destroys the IsisStats object.
void Reset ()
 Reset all accumulators and counters to zero.
void AddData (const double *data, const unsigned int count)
 Add an array of doubles to the accumulators and counters.
void AddData (const double data)
 Add a double to the accumulators and counters.
void RemoveData (const double *data, const unsigned int count)
 Remove an array of doubles from the accumulators and counters.
void RemoveData (const double data)
void SetValidRange (const double minimum=Isis::ValidMinimum, const double maximum=Isis::ValidMaximum)
double ValidMinimum () const
double ValidMaximum () const
bool InRange (const double value)
bool AboveRange (const double value)
bool BelowRange (const double value)
double Average () const
 Computes and returns the average.
double StandardDeviation () const
 Computes and returns the standard deviation.
double Variance () const
 Computes and returns the variance.
double Rms () const
 Computes and returns the rms.
double Minimum () const
 Returns the absolute minimum double found in all data passed through the AddData method.
double Maximum () const
 Returns the absolute maximum double found in all data passed through the AddData method.
double ChebyshevMinimum (const double percent=99.5) const
 This method returns a minimum such that X percent of the data will fall with K standard deviations of the average (Chebyshev's Theorem).
double ChebyshevMaximum (const double percent=99.5) const
 This method returns a maximum such that X percent of the data will fall with K standard deviations of the average (Chebyshev's Theorem).
double BestMinimum (const double percent=99.5) const
 This method returns the better of the absolute minimum or the Chebyshev minimum.
double BestMaximum (const double percent=99.5) const
 This method returns the better of the absolute maximum or the Chebyshev maximum.
double ZScore (const double value) const
 This method returns the better of the z-score of the given value.
BigInt TotalPixels () const
 Returns the total number of pixels processed (valid and invalid).
BigInt ValidPixels () const
 Returns the total number of valid pixels processed.
BigInt OverRangePixels () const
 Returns the total number of pixels over the valid range encountered.
BigInt UnderRangePixels () const
 Returns the total number of pixels under the valid range encountered.
BigInt NullPixels () const
 Returns the total number of NULL pixels encountered.
BigInt LisPixels () const
 Returns the total number of low instrument saturation (LIS) pixels encountered.
BigInt LrsPixels () const
 Returns the total number of low representation saturation (LRS) pixels encountered.
BigInt HisPixels () const
 Returns the total number of high instrument saturation (HIS) pixels encountered.
BigInt HrsPixels () const
 Returns the total number of high representation saturation (HRS) pixels encountered.
BigInt OutOfRangePixels () const
 Returns the total number of pixels outside of the valid range encountered.
double Sum () const
 Returns the sum of all the data.
double SumSquare () const
 Returns the sum of all the squared data.

Detailed Description

This class is used to accumulate statistics on double arrays.

This class is used to accumulate statistics on double arrays. In particular, it is highly useful for obtaining statistics on cube data. Parameters which can be computed are 1) average, 2) standard deviation, 3) variance, 4) minimum, 5) maximum and 6) various counts of valid and/or special pixels.

The following example shows a simple set up and usage of the Statistics class to calculate the average of a set of values:

   Statistics myStats ;
   double myData [] = { 1.0, 3.0, 2.4, 7.5 } ;

   myStats.AddData (myData, 4) ;
   double myAverage = myStats.Average () ;
   cout << "The average of the data is " << myAverage << endl ;

For an example of how the Statistics object is used in Isis, see the Histogram object (inherits from Statistics) and the stats application, stats.cpp (uses the Statistics child class Histogram).

Author:
2002-05-06 Jeff Anderson

Constructor & Destructor Documentation

Isis::Statistics::Statistics (  ) 

Constructs an IsisStats object with accumulators and counters set to zero.

References Reset(), and SetValidRange().

Isis::Statistics::~Statistics (  ) 

Destroys the IsisStats object.


Member Function Documentation

bool Isis::Statistics::AboveRange ( const double  value  )  [inline]

Referenced by AddData(), and RemoveData().

void Isis::Statistics::AddData ( const double  data  )  [inline]

Add a double to the accumulators and counters.

This method can be invoked multiple times (for example: once for each pixel in a cube) before obtaining statistics.

Parameters:
data The data to be added to the data set used for statistical calculations.

References AboveRange(), InRange(), Isis::IsHisPixel(), Isis::IsHrsPixel(), Isis::IsLisPixel(), Isis::IsLrsPixel(), Isis::IsNullPixel(), and Isis::IsValidPixel().

void Isis::Statistics::AddData ( const double *  data,
const unsigned int  count 
)
double Isis::Statistics::Average (  )  const
bool Isis::Statistics::BelowRange ( const double  value  )  [inline]
double Isis::Statistics::BestMaximum ( const double  percent = 99.5  )  const

This method returns the better of the absolute maximum or the Chebyshev maximum.

The better value is considered the value closest to the mean.

Parameters:
percent The probability that the maximum is within K standard deviations of the mean (Used to compute the Chebyshev maximum). Default value = 99.5.
Returns:
Best of absolute and Chebyshev maximums
See also:
Statistics::Maximum Statistics::ChebyshevMaximum

References ChebyshevMaximum(), Maximum(), and Isis::NULL8.

Referenced by Isis::StretchTool::histFromBuffer(), Isis::VisualDisplay::setPixelData(), Isis::LinearStretchType::setStretch(), Isis::StretchTool::stretchBand(), and Isis::StretchTool::stretchBuffer().

double Isis::Statistics::BestMinimum ( const double  percent = 99.5  )  const

This method returns the better of the absolute minimum or the Chebyshev minimum.

The better value is considered the value closest to the mean.

Parameters:
percent The probability that the minimum is within K standard deviations of the mean (Used to compute the Chebyshev minimum). Default value = 99.5.
Returns:
Best of absolute and Chebyshev minimums
See also:
Statistics::Minimum Statistics::ChebyshevMinimum

References ChebyshevMinimum(), min(), Minimum(), and Isis::NULL8.

Referenced by Isis::StretchTool::histFromBuffer(), Isis::VisualDisplay::setPixelData(), Isis::LinearStretchType::setStretch(), Isis::StretchTool::stretchBand(), and Isis::StretchTool::stretchBuffer().

double Isis::Statistics::ChebyshevMaximum ( const double  percent = 99.5  )  const

This method returns a maximum such that X percent of the data will fall with K standard deviations of the average (Chebyshev's Theorem).

It can be used to obtain a minimum that does not include statistical outliers.

Parameters:
percent The probability that the maximum is within K standard deviations of the mean. Default value = 99.5.
Returns:
maximum value excluding statistical outliers
Exceptions:
Isis::iException::Message 

References _FILEINFO_, Average(), Isis::iException::Message(), Isis::NULL8, Isis::iException::Programmer, and StandardDeviation().

Referenced by BestMaximum().

double Isis::Statistics::ChebyshevMinimum ( const double  percent = 99.5  )  const

This method returns a minimum such that X percent of the data will fall with K standard deviations of the average (Chebyshev's Theorem).

It can be used to obtain a minimum that does not include statistical outliers.

Parameters:
percent The probability that the minimum is within K standard deviations of the mean. Default value = 99.5.
Returns:
Minimum value (excluding statistical outliers)
Exceptions:
Isis::iException::Message 

References _FILEINFO_, Average(), Isis::iException::Message(), Isis::NULL8, Isis::iException::Programmer, and StandardDeviation().

Referenced by BestMinimum().

BigInt Isis::Statistics::HisPixels (  )  const

Returns the total number of high instrument saturation (HIS) pixels encountered.

Returns:
The number of HIS pixels (data) processed
BigInt Isis::Statistics::HrsPixels (  )  const

Returns the total number of high representation saturation (HRS) pixels encountered.

Returns:
The number of HRS pixels (data) processed
bool Isis::Statistics::InRange ( const double  value  )  [inline]
BigInt Isis::Statistics::LisPixels (  )  const

Returns the total number of low instrument saturation (LIS) pixels encountered.

Returns:
The number of LIS pixels (data) processed
BigInt Isis::Statistics::LrsPixels (  )  const

Returns the total number of low representation saturation (LRS) pixels encountered.

Returns:
The number of LRS pixels (data) processed
double Isis::Statistics::Maximum (  )  const

Returns the absolute maximum double found in all data passed through the AddData method.

If there are no valid pixels, then NULL8 is returned.

Returns:
Current maximum value in data set
Exceptions:
Isis::iException::Message The data set is blank, so the maximum is invalid.

References _FILEINFO_, Isis::iException::Message(), Isis::NULL8, and Isis::iException::Programmer.

Referenced by BestMaximum(), Isis::GaussianStretch::GaussianStretch(), Isis::ControlNetStatistics::GenerateControlNetStats(), Isis::ControlNet::GetMaximumResidual(), Isis::VisualDisplay::paintPixmap(), Isis::SawtoothStretchType::SawtoothStretchType(), Isis::HistogramWidget::setHistogram(), Isis::StretchTool::stretchBuffer(), and ZScore().

double Isis::Statistics::Minimum (  )  const

Returns the absolute minimum double found in all data passed through the AddData method.

If there are no valid pixels, then NULL8 is returned.

Returns:
Current minimum value in data set.
Exceptions:
Isis::iException::Message The data set is blank, so the minimum is invalid.

References _FILEINFO_, Isis::iException::Message(), Isis::NULL8, and Isis::iException::Programmer.

Referenced by BestMinimum(), Isis::GaussianStretch::GaussianStretch(), Isis::ControlNetStatistics::GenerateControlNetStats(), Isis::VisualDisplay::paintPixmap(), Isis::SawtoothStretchType::SawtoothStretchType(), Isis::HistogramWidget::setHistogram(), and Isis::StretchTool::stretchBuffer().

BigInt Isis::Statistics::NullPixels (  )  const

Returns the total number of NULL pixels encountered.

Returns:
The number of NULL pixels (data) processed
BigInt Isis::Statistics::OutOfRangePixels (  )  const

Returns the total number of pixels outside of the valid range encountered.

Returns:
The number of Out of Range pixels (data) processed
BigInt Isis::Statistics::OverRangePixels (  )  const

Returns the total number of pixels over the valid range encountered.

Returns:
The number of pixels less than the ValidMaximum() processed
void Isis::Statistics::RemoveData ( const double  data  ) 

References RemoveData().

void Isis::Statistics::RemoveData ( const double *  data,
const unsigned int  count 
)

Remove an array of doubles from the accumulators and counters.

Note that is invalidates the absolute minimum and maximum. They will no longer be usable.

Parameters:
data The data to be removed from data set used for statistical calculations.
count The number of elements in the data to be removed.
Exceptions:
Isis::iException::Message RemoveData is trying to remove data that doesn't exist.

Reimplemented in Isis::Histogram.

References _FILEINFO_, AboveRange(), InRange(), Isis::IsHisPixel(), Isis::IsHrsPixel(), Isis::IsLisPixel(), Isis::IsLrsPixel(), Isis::IsNullPixel(), Isis::IsValidPixel(), Isis::iException::Message(), and Isis::iException::Programmer.

Referenced by RemoveData().

void Isis::Statistics::Reset (  ) 
double Isis::Statistics::Rms (  )  const

Computes and returns the rms.

If there are no valid pixels, then NULL8 is returned.

Returns:
The rms (root mean square)

References Isis::NULL8.

Referenced by Isis::ControlPoint::GetLineResidualRms(), Isis::ControlPoint::GetResidualRms(), and Isis::ControlPoint::GetSampleResidualRms().

void Isis::Statistics::SetValidRange ( const double  minimum = Isis::ValidMinimum,
const double  maximum = Isis::ValidMaximum 
)
double Isis::Statistics::StandardDeviation (  )  const

Computes and returns the standard deviation.

If there are no valid pixels, then NULL8 is returned.

Returns:
The standard deviation

Reimplemented in Isis::GaussianDistribution.

References Isis::NULL8, and Variance().

Referenced by ChebyshevMaximum(), ChebyshevMinimum(), Isis::VisualDisplay::paintPixmap(), Isis::ReseauDistortionMap::SetFocalPlane(), Isis::ReseauDistortionMap::SetUndistortedFocalPlane(), Isis::Histogram::Skew(), Isis::OverlapStatistics::toPvl(), and ZScore().

double Isis::Statistics::Sum (  )  const [inline]

Returns the sum of all the data.

Returns:
The sum of the data
double Isis::Statistics::SumSquare (  )  const [inline]

Returns the sum of all the squared data.

Returns:
The sum of the squared data

Referenced by Isis::BundleAdjust::Solve().

BigInt Isis::Statistics::TotalPixels (  )  const

Returns the total number of pixels processed (valid and invalid).

Returns:
The number of pixels (data) processed

Referenced by Isis::VisualDisplay::paintPixmap(), and Isis::BundleAdjust::Solve().

BigInt Isis::Statistics::UnderRangePixels (  )  const

Returns the total number of pixels under the valid range encountered.

Returns:
The number of pixels less than the ValidMinimum() processed
double Isis::Statistics::ValidMaximum (  )  const [inline]
double Isis::Statistics::ValidMinimum (  )  const [inline]
BigInt Isis::Statistics::ValidPixels (  )  const

Returns the total number of valid pixels processed.

Only valid pixels are utilized when computing the average, standard deviation, variance, minimum and maximum.

Returns:
The number of valid pixels (data) processed

Referenced by Isis::OverlapNormalization::AddOverlap(), Isis::QHistogram::Load(), Isis::Histogram::Percent(), Isis::Histogram::Skew(), Isis::StretchTool::stretchBuffer(), and Isis::StretchTool::updateHistograms().

double Isis::Statistics::Variance (  )  const

Computes and returns the variance.

If there are no valid pixels, then NULL8 is returned.

Returns:
The variance

References Isis::NULL8.

Referenced by StandardDeviation(), and Isis::OverlapStatistics::toPvl().

double Isis::Statistics::ZScore ( const double  value  )  const

This method returns the better of the z-score of the given value.

The z-score is the number of standard deviations the value lies above or below the average.

Parameters:
value The value to calculate the z-score of.
Returns:
z-score

References _FILEINFO_, Average(), Maximum(), Isis::iException::Message(), Isis::iException::Programmer, and StandardDeviation().


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