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Isis Developer Reference
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Isis Developer Reference
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Container of multivariate statistics. More...
#include <MultivariateStatistics.h>
Public Member Functions | |
| MultivariateStatistics () | |
| Constructs a Multivariate Statistics object with accumulators and counters set to zero. | |
| MultivariateStatistics (const PvlObject &inStats) | |
| Constructs a MulitvariateStatistics object from a PvlObject. | |
| ~MultivariateStatistics () | |
| Destructs a MultivariateStatistics object. | |
| void | Reset () |
| Resets all accumulators to zero. | |
| void | AddData (const double *x, const double *y, const unsigned int count) |
| Add two arrays of doubles to the accumulators and counters. | |
| void | AddData (double x, double y, unsigned int count=1) |
| Add an x,y value to the accumulators and counters count times. | |
| void | RemoveData (const double *x, const double *y, const unsigned int count) |
| Remove an array of doubles from the accumulators and counters. | |
| Isis::Statistics | X () const |
| Returns a Stats object for all of the X data fed through the AddData method. | |
| Isis::Statistics | Y () const |
| Returns a Stats object for all of the Y data fed through the AddData method. | |
| double | SumXY () const |
| Returns the sum of x*y for all data given through the AddData method. | |
| double | Covariance () const |
| Computes and returns the covariance between the two data sets If there are no valid data (pixels) then NULL8 is returned. | |
| double | Correlation () const |
| Computes and returns the coefficient of correlation (between -1.0 and 1.0) of the two data sets. | |
| void | LinearRegression (double &a, double &b) const |
| Fits a line. | |
| BigInt | ValidPixels () const |
| Returns the number of valid pixels processed. | |
| BigInt | InvalidPixels () const |
| Returns the number of invalid pixels encountered. | |
| BigInt | TotalPixels () const |
| Returns the total number of pixels processed. | |
| PvlObject | toPvl (QString name="MultivariateStatistics") const |
| Serializes a multivariate statistics object as a PvlObject. | |
Container of multivariate statistics.
This class is used to accumulate multivariate statisics on two double arrays. In particular, it is highly useful for obtaining the covariance, correlation, and linear regression analysis on the the data. It ignores input values which are Isis special pixel values. That is, if either co-aligned double value is a special pixel then both values are not used in any statistical computation.
| Isis::MultivariateStatistics::MultivariateStatistics | ( | ) |
Constructs a Multivariate Statistics object with accumulators and counters set to zero.
References Reset().
| Isis::MultivariateStatistics::MultivariateStatistics | ( | const PvlObject & | inStats | ) |
| Isis::MultivariateStatistics::~MultivariateStatistics | ( | ) |
Destructs a MultivariateStatistics object.
| void Isis::MultivariateStatistics::AddData | ( | const double * | x, |
| const double * | y, | ||
| const unsigned int | count ) |
Add two arrays of doubles to the accumulators and counters.
This method can be invoked multiple times, for example, once for each line in a cube, before obtaining statistics.
| x | Array of doubles to add. |
| y | Array of doubles to add. |
| count | Number of doubles to process. |
References Isis::Statistics::AddData(), and Isis::IsValidPixel().
Referenced by Isis::MaximumCorrelation::MatchAlgorithm().
| void Isis::MultivariateStatistics::AddData | ( | double | x, |
| double | y, | ||
| unsigned int | count = 1 ) |
Add an x,y value to the accumulators and counters count times.
This method can be invoked multiple times before obtaining statistics.
| x | x value to add |
| y | y value to add |
| count | Number of times to add this x,y value |
References Isis::Statistics::AddData(), and Isis::IsValidPixel().
| double Isis::MultivariateStatistics::Correlation | ( | ) | const |
Computes and returns the coefficient of correlation (between -1.0 and 1.0) of the two data sets.
This can be used as a goodness-of-fit measurement. The close the correlation is two -1.0 or 1.0 the more likely the data sets are related (and therefore the regression equation is valid).
References Covariance(), Isis::NULL8, and Isis::Statistics::StandardDeviation().
Referenced by toPvl().
| double Isis::MultivariateStatistics::Covariance | ( | ) | const |
Computes and returns the covariance between the two data sets If there are no valid data (pixels) then NULL8 is returned.
References Isis::Statistics::Average(), Isis::NULL8, and Isis::Statistics::Sum().
Referenced by Correlation(), and toPvl().
| BigInt Isis::MultivariateStatistics::InvalidPixels | ( | ) | const |
Returns the number of invalid pixels encountered.
Referenced by toPvl().
| void Isis::MultivariateStatistics::LinearRegression | ( | double & | a, |
| double & | b ) const |
Fits a line.
\[ y=A+Bx \]
through the data.
| a | The additive constant A. |
| b | The additive constant B. |
References _FILEINFO_, Isis::IException::Programmer, Isis::Statistics::Sum(), and Isis::Statistics::SumSquare().
Referenced by toPvl().
| void Isis::MultivariateStatistics::RemoveData | ( | const double * | x, |
| const double * | y, | ||
| const unsigned int | count ) |
Remove an array of doubles from the accumulators and counters.
| x | Pointer to an array of doubles to remove. |
| y | Array of doubles to add. |
| count | Number of doubles to process. |
References _FILEINFO_, Isis::IsValidPixel(), Isis::IException::Programmer, and Isis::Statistics::RemoveData().
| void Isis::MultivariateStatistics::Reset | ( | ) |
Resets all accumulators to zero.
References Isis::Statistics::Reset().
Referenced by MultivariateStatistics(), and MultivariateStatistics().
| double Isis::MultivariateStatistics::SumXY | ( | ) | const |
Returns the sum of x*y for all data given through the AddData method.
Referenced by toPvl().
| PvlObject Isis::MultivariateStatistics::toPvl | ( | QString | name = "MultivariateStatistics" | ) | const |
Serializes a multivariate statistics object as a PvlObject.
| QString | (Default value is "MultivariateStatistics") - Name of the PvlObject |
References Correlation(), Covariance(), InvalidPixels(), LinearRegression(), SumXY(), Isis::Statistics::toPvl(), Isis::toString(), TotalPixels(), ValidPixels(), X(), and Y().
| BigInt Isis::MultivariateStatistics::TotalPixels | ( | ) | const |
Returns the total number of pixels processed.
Referenced by toPvl().
| BigInt Isis::MultivariateStatistics::ValidPixels | ( | ) | const |
Returns the number of valid pixels processed.
Only valid pixels are utilized when computing the average, standard deviation, variance, minimum, and maximum.
Referenced by Isis::OverlapStatistics::IsValid(), and toPvl().
| Isis::Statistics Isis::MultivariateStatistics::X | ( | ) | const |
Returns a Stats object for all of the X data fed through the AddData method.
Referenced by toPvl().
| Isis::Statistics Isis::MultivariateStatistics::Y | ( | ) | const |
Returns a Stats object for all of the Y data fed through the AddData method.
Referenced by toPvl().