# PHP Statistics Functions

EditRocket provides the following information on Statistics functions in the PHP source code builder.

float stats_absolute_deviation ( array \$a ) -

float stats_cdf_beta ( float \$par1 , float \$par2 , float \$par3 , int \$which ) - Method Cumulative distribution function (P) is calculated directly by code associated with the following reference. DiDinato, A. R. and Morris, A. H. Algorithm 708: Significant Digit Computation of the Incomplete Beta Function Ratios. ACM Trans. Math. Softw. 18 (1993), 360-373. Computation of other parameters involve a search for a value that produces the desired value of P. The search relies on the monotinicity of P with the other parameter. Note The beta density is proportional to t^(A-1) * (1-t)^(B-1) Arguments P -- The integral from 0 to X of the chi-square distribution. Input range: [0, 1]. Q -- 1-P. Input range: [0, 1]. P + Q = 1.0. X -- Upper limit of integration of beta density. Input range: [0,1]. Search range: [0,1] Y -- 1-X. Input range: [0,1]. Search range: [0,1] X + Y = 1.0. A -- The first parameter of the beta density. Input range: (0, +infinity). Search range: [1D-100,1D100] B -- The second parameter of the beta density. Input range: (0, +infinity). Search range: [1D-100,1D100] STATUS -- 0 if calculation completed correctly -I if input parameter number I is out of range 1 if answer appears to be lower than lowest search bound 2 if answer appears to be higher than greatest search bound 3 if P + Q .ne. 1 4 if X + Y .ne. 1 BOUND -- Undefined if STATUS is 0 Bound exceeded by parameter number I if STATUS is negative. Lower search bound if STATUS is 1. Upper search bound if STATUS is 2.

float stats_cdf_binomial ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_cdf_cauchy ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_cdf_chisquare ( float \$par1 , float \$par2 , int \$which ) -

float stats_cdf_exponential ( float \$par1 , float \$par2 , int \$which ) -

float stats_cdf_f ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_cdf_gamma ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_cdf_laplace ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_cdf_logistic ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_cdf_negative_binomial ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_cdf_noncentral_chisquare ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_cdf_noncentral_f ( float \$par1 , float \$par2 , float \$par3 , float \$par4 , int \$which ) -

float stats_cdf_poisson ( float \$par1 , float \$par2 , int \$which ) -

float stats_cdf_t ( float \$par1 , float \$par2 , int \$which ) -

float stats_cdf_uniform ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_cdf_weibull ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_covariance ( array \$a , array \$b ) -

float stats_den_uniform ( float \$x , float \$a , float \$b ) -

float stats_dens_beta ( float \$x , float \$a , float \$b ) -

float stats_dens_cauchy ( float \$x , float \$ave , float \$stdev ) -

float stats_dens_chisquare ( float \$x , float \$dfr ) -

float stats_dens_exponential ( float \$x , float \$scale ) -

float stats_dens_f ( float \$x , float \$dfr1 , float \$dfr2 ) -

float stats_dens_gamma ( float \$x , float \$shape , float \$scale ) -

float stats_dens_laplace ( float \$x , float \$ave , float \$stdev ) -

float stats_dens_logistic ( float \$x , float \$ave , float \$stdev ) -

float stats_dens_negative_binomial ( float \$x , float \$n , float \$pi ) -

float stats_dens_normal ( float \$x , float \$ave , float \$stdev ) -

float stats_dens_pmf_binomial ( float \$x , float \$n , float \$pi ) -

float stats_dens_pmf_hypergeometric ( float \$n1 , float \$n2 , float \$N1 , float \$N2 ) -

float stats_dens_pmf_poisson ( float \$x , float \$lb ) -

float stats_dens_t ( float \$x , float \$dfr ) -

float stats_dens_weibull ( float \$x , float \$a , float \$b ) -

number stats_harmonic_mean ( array \$a ) -

float stats_kurtosis ( array \$a ) -

float stats_rand_gen_beta ( float \$a , float \$b ) - Returns a random deviate from the beta distribution with parameters A and B. The density of the beta is x^(a-1) * (1-x)^(b-1) / B(a,b) for 0 < x <. Method R. C. H. Cheng.

float stats_rand_gen_chisquare ( float \$df ) -

float stats_rand_gen_exponential ( float \$av ) -

float stats_rand_gen_f ( float \$dfn , float \$dfd ) - Generates a random deviate from the F (variance ratio) distribution with dfn degrees of freedom in the numerator and dfd degrees of freedom in the denominator. Method : directly generates ratio of chisquare variates.

float stats_rand_gen_funiform ( float \$low , float \$high ) -

float stats_rand_gen_gamma ( float \$a , float \$r ) - Generates random deviates from the gamma distribution whose density is (A**R)/Gamma(R) * X**(R-1) * Exp(-A*X).

int stats_rand_gen_ibinomial ( int \$n , float \$pp ) -

int stats_rand_gen_ibinomial_negative ( int \$n , float \$p ) -

int stats_rand_gen_int ( void ) -

int stats_rand_gen_ipoisson ( float \$mu ) -

int stats_rand_gen_iuniform ( int \$low , int \$high ) -

float stats_rand_gen_noncenral_chisquare ( float \$df , float \$xnonc ) -

float stats_rand_gen_noncentral_f ( float \$dfn , float \$dfd , float \$xnonc ) -

float stats_rand_gen_noncentral_t ( float \$df , float \$xnonc ) -

float stats_rand_gen_normal ( float \$av , float \$sd ) -

float stats_rand_gen_t ( float \$df ) -

array stats_rand_get_seeds ( void ) -

array stats_rand_phrase_to_seeds ( string \$phrase ) -

float stats_rand_ranf ( void ) -

void stats_rand_setall ( int \$iseed1 , int \$iseed2 ) -

float stats_skew ( array \$a ) -

float stats_standard_deviation ( array \$a [, bool \$sample ] ) -

float stats_stat_binomial_coef ( int \$x , int \$n ) -

float stats_stat_correlation ( array \$arr1 , array \$arr2 ) -

float stats_stat_gennch ( int \$n ) -

float stats_stat_independent_t ( array \$arr1 , array \$arr2 ) -

float stats_stat_innerproduct ( array \$arr1 , array \$arr2 ) -

float stats_stat_noncentral_t ( float \$par1 , float \$par2 , float \$par3 , int \$which ) -

float stats_stat_paired_t ( array \$arr1 , array \$arr2 ) -

float stats_stat_percentile ( float \$df , float \$xnonc ) -

float stats_stat_powersum ( array \$arr , float \$power ) -

float stats_variance ( array \$a [, bool \$sample ] ) -