MeanSD

Output range to compute mean, stdev, variance online. Getter methods * for stdev, var cost a few floating point ops. Getter for mean costs * a single branch to check for N == 0. Relatively expensive floating point * ops, if you only need mean, try Mean. This struct uses O(1) space and * does *NOT* store the individual elements. * * Note: This struct can implicitly convert to a Mean struct. * * References: Computing Higher-Order Moments Online. * http://people.xiph.org/~tterribe/notes/homs.html * * Examples: * --- * MeanSD summ; * summ.put(1); * summ.put(2); * summ.put(3); * summ.put(4); * summ.put(5); * assert(summ.mean == 3); * assert(summ.stdev == sqrt(2.5)); * assert(summ.var == 2.5); * ---

struct MeanSD {

void put(double element);

void put(typeof(this) rhs);

double sum [@property getter];

double mean [@property getter];

double stdev [@property getter];

double var [@property getter];

double mse [@property getter];

double N [@property getter];

Mean toMean [@property getter];

MeanSD toMeanSD [@property getter];

string toString();

}

put void put(double element)
put void put(typeof(this) rhs): Combine two MeanSD's.
toString string toString()

Properties

N double N [@property getter]
mean double mean [@property getter]
mse double mse [@property getter]: Mean squared error. In other words, a biased estimate of variance.
stdev double stdev [@property getter]
sum double sum [@property getter]
toMean Mean toMean [@property getter]: Converts this struct to a Mean struct. Also called when an implicit conversion via alias this takes place.
toMeanSD MeanSD toMeanSD [@property getter]: Simply returns this. Useful in generic programming contexts.
var double var [@property getter]

The OpenD Programming Language

MeanSD

Alias This

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