SSJ
V. 2.1.3.

## umontreal.iro.lecuyer.randvar Class Rand1

java.lang.Object
umontreal.iro.lecuyer.randvar.Rand1


Deprecated. Use RandomVariateGen and RandomVariateGenInt instead.

public class Rand1extends Object

This static class provides a few methods for generating random variates from various distributions, using a given random stream. All the methods given here use inversion.

This is an OLD class that is DEPRECATED. Equivalent methods in the appropriate classes of this package should be used instead.

Method Summary
static int binomial(RandomStream s, int n, double p)
Deprecated. Returns a random variate having the binomial distribution with parameters n and p, using stream s.
static double chiSquare(RandomStream s, int n)
Deprecated. Returns a random variate having the ChiSquare distribution with parameters n.
static double erlang(RandomStream s, int k, double mu)
Deprecated. Returns a random variate having the Erlang distribution.
static double expon(RandomStream s, double mean)
Deprecated. Returns a random variate having the exponential distribution with mean = mean, using stream s.
static int geometric(RandomStream s, double p)
Deprecated. Returns a random variate having the geometric distribution with parameter p, where 0 < p < 1, using stream s.
static double gumbel(RandomStream s, double alpha, double lambda)
Deprecated. Returns a random variate having the Gumbel distribution with parameters alpha and lambda (see, Problem 8.1).
static double invStudentDist(int n, double u)
Deprecated. Returns y = F-1(u), where F is the Student distribution function with n degrees of freedom.
static double Logistic(RandomStream s, double alpha, double lambda)
Deprecated. Returns a Logistic random variate with parameters alpha and standard deviation lambda, using stream s.
static double lognormal(RandomStream s, double mu, double sigma)
Deprecated. Returns a random variate having the lognormal distribution.
static int negativeBinomial(RandomStream s, int n, double p)
Deprecated. Returns a random variate having the binomial distribution with parameters n and p, using stream s.
static double normal(RandomStream s, double mean, double sigma)
Deprecated. Returns a normal random variate with mean mu and standard deviation sigma using stream s.
static double pareto(RandomStream s, double alpha, double beta)
Deprecated. Returns a random variate having the Pareto distribution with parameters alpha and (see, Problem 8.1).
static int poisson(RandomStream s, double lambda)
Deprecated. Returns a random variate having the Poisson distribution with parameter (mean) lambda.
static double student(RandomStream s, int n)
Deprecated. Returns a random variate having the Student distribution with n degrees of freedom, using stream s.
static double uniform(RandomStream s, double a, double b)
Deprecated. Returns a random variate having the uniform distribution over the real interval (a, b), using stream s.
static double weibull(RandomStream s, double alpha, double lambda, double delta)
Deprecated. Returns a random variate having the Weibull distribution.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

### uniform

public static double uniform(RandomStream s,
double a,
double b)
Deprecated.
Returns a random variate having the uniform distribution over the real interval (a, b), using stream s. The returned value is always strictly between a and b.

### expon

public static double expon(RandomStream s,
double mean)
Deprecated.
Returns a random variate having the exponential distribution with mean = mean, using stream s. Uses inversion.

### erlang

public static double erlang(RandomStream s,
int k,
double mu)
Deprecated.
Returns a random variate having the Erlang distribution. It has parameters (k,[tex2html_wrap_inline329]), which is the sum of k exponential random variables with mean [tex2html_wrap_inline332]. The mean of this Erlang random variable is k[tex2html_wrap_inline334]. This method simply generates k exponentials by calling ExponentialDist.inverseF k times with stream s, and returns the sum.

### weibull

public static double weibull(RandomStream s,
double alpha,
double lambda,
double delta)
Deprecated.
Returns a random variate having the Weibull distribution. It has parameters = alpha and = lambda, using stream s. This Weibull distribution function is F(x) = 1 - e-x for x > 0. The mean is given by (1+1/[tex2html_wrap_inline347])/. Restrictions: must have [tex2html_wrap_inline350] > 0 et [tex2html_wrap_inline352] > 0. Uses inversion.

### normal

public static double normal(RandomStream s,
double mean,
double sigma)
Deprecated.
Returns a normal random variate with mean mu and standard deviation sigma using stream s. Uses inversion via invNormalDist.

### Logistic

public static double Logistic(RandomStream s,
double alpha,
double lambda)
Deprecated.
Returns a Logistic random variate with parameters alpha and standard deviation lambda, using stream s. Uses inversion via .

### student

public static double student(RandomStream s,
int n)
Deprecated.
Returns a random variate having the Student distribution with n degrees of freedom, using stream s. Uses inversion via invStudentDist.

### invStudentDist

public static double invStudentDist(int n,
double u)
Deprecated.
Returns y = F-1(u), where F is the Student distribution function with n degrees of freedom.

### lognormal

public static double lognormal(RandomStream s,
double mu,
double sigma)
Deprecated.
Returns a random variate having the lognormal distribution. It has parameters [tex2html_wrap_inline364] and [tex2html_wrap_inline366], i.e., whose natural logarithm is normal with mean [tex2html_wrap_inline368] and variance . Generates a normal by inversion and takes the exponential.

### chiSquare

public static double chiSquare(RandomStream s,
int n)
Deprecated.
Returns a random variate having the ChiSquare distribution with parameters n. Uses inversion.

### gumbel

public static double gumbel(RandomStream s,
double alpha,
double lambda)
Deprecated.
Returns a random variate having the Gumbel distribution with parameters alpha and lambda (see, Problem 8.1). Uses inversion.

### pareto

public static double pareto(RandomStream s,
double alpha,
double beta)
Deprecated.
Returns a random variate having the Pareto distribution with parameters alpha and (see, Problem 8.1). Uses inversion.

### binomial

public static int binomial(RandomStream s,
int n,
double p)
Deprecated.
Returns a random variate having the binomial distribution with parameters n and p, using stream s. The parameter p must be in [0, 1]. This method is efficient only for small n (say, n <= 10).

### negativeBinomial

public static int negativeBinomial(RandomStream s,
int n,
double p)
Deprecated.
Returns a random variate having the binomial distribution with parameters n and p, using stream s. The parameter p must be in [0, 1]. This method is efficient only for small n (say, n <= 10).

### geometric

public static int geometric(RandomStream s,
double p)
Deprecated.
Returns a random variate having the geometric distribution with parameter p, where 0 < p < 1, using stream s. Uses inversion.

### poisson

public static int poisson(RandomStream s,
double lambda)
Deprecated.
Returns a random variate having the Poisson distribution with parameter (mean) lambda. One must have lambda > 0 and this method is efficient only for small lambda (say, lambda  <= 10).

Uses Tabulated Inversion combined with Acceptance Complement strongly inspired from the UNURAN library.

SSJ
V. 2.1.3.

To submit a bug or ask questions, send an e-mail to Pierre L'Ecuyer.