﻿ Statistics Functions

# Statistics Functions

## Introduction

This is the statistics extension. It contains few dozens of functions useful for statistical computations. It is a wrapper around 2 scientific libraries, namely DCDFLIB (Library of C routines for Cumulative Distributions Functions, Inverses, and Other parameters) by B. Brown & J. Lavato and RANDLIB by Barry Brown, James Lavato & Kathy Russell. Includes CD and PD functions.

## Installation

This » PECL extension is not bundled with PHP.

Information for installing this PECL extension may be found in the manual chapter titled Installation of PECL extensions. Additional information such as new releases, downloads, source files, maintainer information, and a CHANGELOG, can be located here: » http://pecl.php.net/package/stats.

## Requirements

No external libraries are needed. The extension comes bundled with the libraries used.

stats_absolute_deviation — Returns the absolute deviation of an array of values
stats_cdf_beta — CDF function for BETA Distribution. Calculates any one parameter of the beta distribution given values for the others.
stats_cdf_binomial — Calculates any one parameter of the binomial distribution given values for the others.
stats_cdf_cauchy — Not documented
stats_cdf_chisquare — Calculates any one parameter of the chi-square distribution given values for the others.
stats_cdf_exponential — Not documented
stats_cdf_f — Calculates any one parameter of the F distribution given values for the others.
stats_cdf_gamma — Calculates any one parameter of the gamma distribution given values for the others.
stats_cdf_laplace — Not documented
stats_cdf_logistic — Not documented
stats_cdf_negative_binomial — Calculates any one parameter of the negative binomial distribution given values for the others.
stats_cdf_noncentral_chisquare — Calculates any one parameter of the non-central chi-square distribution given values for the others.
stats_cdf_noncentral_f — Calculates any one parameter of the Non-central F distribution given values for the others.
stats_cdf_poisson — Calculates any one parameter of the Poisson distribution given values for the others.
stats_cdf_t — Calculates any one parameter of the T distribution given values for the others.
stats_cdf_uniform — Not documented
stats_cdf_weibull — Not documented
stats_covariance — Computes the covariance of two data sets
stats_den_uniform — Not documented
stats_dens_beta — Not documented
stats_dens_cauchy — Not documented
stats_dens_chisquare — Not documented
stats_dens_exponential — Not documented
stats_dens_f
stats_dens_gamma — Not documented
stats_dens_laplace — Not documented
stats_dens_logistic — Not documented
stats_dens_negative_binomial — Not documented
stats_dens_normal — Not documented
stats_dens_pmf_binomial — Not documented
stats_dens_pmf_hypergeometric
stats_dens_pmf_poisson — Not documented
stats_dens_t — Not documented
stats_dens_weibull — Not documented
stats_harmonic_mean — Returns the harmonic mean of an array of values
stats_kurtosis — Computes the kurtosis of the data in the array
stats_rand_gen_beta — Generates beta random deviate
stats_rand_gen_chisquare — Generates random deviate from the distribution of a chisquare with "df" degrees of freedom random variable.
stats_rand_gen_exponential — Generates a single random deviate from an exponential distribution with mean "av"
stats_rand_gen_f — Generates a random deviate
stats_rand_gen_funiform — Generates uniform float between low (exclusive) and high (exclusive)
stats_rand_gen_gamma — Generates random deviates from a gamma distribution
stats_rand_gen_ibinomial_negative — Generates a single random deviate from a negative binomial distribution. Arguments : n - the number of trials in the negative binomial distribution from which a random deviate is to be generated (n > 0), p - the probability of an event (0 < p < 1)).
stats_rand_gen_ibinomial — Generates a single random deviate from a binomial distribution whose number of trials is "n" (n >= 0) and whose probability of an event in each trial is "pp" ([0;1]). Method : algorithm BTPE
stats_rand_gen_int — Generates random integer between 1 and 2147483562
stats_rand_gen_ipoisson — Generates a single random deviate from a Poisson distribution with mean "mu" (mu >= 0.0).
stats_rand_gen_iuniform — Generates integer uniformly distributed between LOW (inclusive) and HIGH (inclusive)
stats_rand_gen_noncenral_chisquare — Generates random deviate from the distribution of a noncentral chisquare with "df" degrees of freedom and noncentrality parameter "xnonc". d must be >= 1.0, xnonc must >= 0.0
stats_rand_gen_noncentral_f — Generates a random deviate from the noncentral F (variance ratio) distribution with "dfn" degrees of freedom in the numerator, and "dfd" degrees of freedom in the denominator, and noncentrality parameter "xnonc". Method : directly generates ratio of noncentral numerator chisquare variate to central denominator chisquare variate.
stats_rand_gen_noncentral_t — Generates a single random deviate from a noncentral T distribution
stats_rand_gen_normal — Generates a single random deviate from a normal distribution with mean, av, and standard deviation, sd (sd >= 0). Method : Renames SNORM from TOMS as slightly modified by BWB to use RANF instead of SUNIF.
stats_rand_gen_t — Generates a single random deviate from a T distribution
stats_rand_get_seeds — Not documented
stats_rand_phrase_to_seeds — generate two seeds for the RGN random number generator
stats_rand_ranf — Returns a random floating point number from a uniform distribution over 0 - 1 (endpoints of this interval are not returned) using the current generator
stats_rand_setall — Not documented
stats_skew — Computes the skewness of the data in the array
stats_standard_deviation — Returns the standard deviation
stats_stat_binomial_coef — Not documented
stats_stat_correlation — Not documented
stats_stat_gennch — Not documented
stats_stat_independent_t — Not documented
stats_stat_innerproduct
stats_stat_noncentral_t — Calculates any one parameter of the noncentral t distribution give values for the others.
stats_stat_paired_t — Not documented
stats_stat_percentile — Not documented
stats_stat_powersum — Not documented
stats_variance — Returns the population variance

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