Accumulator Class Reference
[Useful math tools]

Class to compute simple statistics of a stream of (currently real) numbers. More...

#include <quantum.h>

List of all members.

Public Member Functions

Accumulator ()

Default constructor: creates an empty accumulator.

number Sum ()

Returns the sum of all accumulated samples. $\sigma = \sum_{i=1}^N{x_i}$ .

number Count ()

Returns the number of samples accumulated. $N = \sum_{i=1}^N{1}$ .

number SqSum ()

Returns the sum of the squares of all accumulated samples: $\Sigma = \sum_{i=1}^N{x_i^2}$ .

number Mean ()

Returns the sample mean: $\overline{x} = \sigma / N$ .

number MeanSq ()

Returns the mean of the squares: $\overline{x^2} = \Sigma / N$ .

number RMS ()

Returns the RMS value: $x_{\scriptscriptstyle\mathrm{RMS}} = \sqrt{\Sigma / N}$ .

number SampleVariance ()

Returns the sample variance: $\Delta^2_{\scriptscriptstyle x} = (\overline{x^2} -\overline{x}^2) / N$ .

number PopVariance ()

Returns the estimated population variance: $\Delta^2_{\scriptscriptstyle\mathrm{pop}} = (\overline{x^2} -\overline{x}^2) / (N-1)$ .

number PopStdDev ()

Returns the estimated standard deviation of the population: $\Delta_{\scriptscriptstyle\mathrm{pop}} = \sqrt{\Delta^2_{\scriptscriptstyle\mathrm{pop}}}$ .

number StdDevMean ()

Returns the estimated standard deviation of the mean: $\Delta \overline{x} = \Delta_{\scriptscriptstyle\mathrm{pop}} / \sqrt{N}$ .

Accumulator & Reset ()

Discards all samples.

Accumulator & operator+= (number num)

Adds a sample num to the accumulator.

Accumulator & operator-= (number num)

Adds a sample -num to the accumulator. NOTE: does not delete a sample!

Detailed Description

Class to compute simple statistics of a stream of (currently real) numbers.

The Accumulator class is a convenient way to compute certain statistics for a stream of (currently) real numbers. Extending this to other types would be fairly easy. Statistics that can be computed are:

the number of samples,
the sum, mean value, and RMS value,
the sum of the squares and the mean of the squares,
the sample variance and the population variance,
the standard deviation of the population and of the mean.

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

quantum.h

Generated on Wed Jun 14 22:25:27 2006 for linalg by

1.4.4


Public Member Functions
	Accumulator ()
	Default constructor: creates an empty accumulator.
number	Sum ()
	Returns the sum of all accumulated samples. $\sigma = \sum_{i=1}^N{x_i}$ .
number	Count ()
	Returns the number of samples accumulated. $N = \sum_{i=1}^N{1}$ .
number	SqSum ()
	Returns the sum of the squares of all accumulated samples: $\Sigma = \sum_{i=1}^N{x_i^2}$ .
number	Mean ()
	Returns the sample mean: $\overline{x} = \sigma / N$ .
number	MeanSq ()
	Returns the mean of the squares: $\overline{x^2} = \Sigma / N$ .
number	RMS ()
	Returns the RMS value: $x_{\scriptscriptstyle\mathrm{RMS}} = \sqrt{\Sigma / N}$ .
number	SampleVariance ()
	Returns the sample variance: $\Delta^2_{\scriptscriptstyle x} = (\overline{x^2} -\overline{x}^2) / N$ .
number	PopVariance ()
	Returns the estimated population variance: $\Delta^2_{\scriptscriptstyle\mathrm{pop}} = (\overline{x^2} -\overline{x}^2) / (N-1)$ .
number	PopStdDev ()
	Returns the estimated standard deviation of the population: $\Delta_{\scriptscriptstyle\mathrm{pop}} = \sqrt{\Delta^2_{\scriptscriptstyle\mathrm{pop}}}$ .
number	StdDevMean ()
	Returns the estimated standard deviation of the mean: $\Delta \overline{x} = \Delta_{\scriptscriptstyle\mathrm{pop}} / \sqrt{N}$ .
Accumulator &	Reset ()
	Discards all samples.
Accumulator &	operator+= (number num)
	Adds a sample `num` to the accumulator.
Accumulator &	operator-= (number num)
	Adds a sample `-num` to the accumulator. NOTE: does not delete a sample!

Accumulator Class Reference [Useful math tools]

Public Member Functions

Detailed Description

Accumulator Class Reference
[Useful math tools]