LabVIEW 2012 MathScript RT模块帮助
版本日期：June 2012
产品编号：373123C0118
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Owning Class: statistics
Requires: MathScript RT Module
Syntax
r = random(type, a, b, c)
r = random(type, a, b, c, m)
r = random(type, a, b, c, n)
r = random(type, a, b, c, m, n)
r = random(type, a, b, c, [m, n])
Description
Generates random numbers according to a specified distribution. random(type, a, b, c) generates a single random number. random(type, a, b, c, m) and random(type, a, b, c, n) generate an mbym and nbyn matrix, respectively. random(type, a, b, c, m, n) and random(type, a, b, c, [m, n]) generate an mbyn matrix.
Details
Examples
Inputs
Name 
Description 
type 
Specifies the type of distribution. type is a string that accepts the following values.
'beta' 
Specifies a beta distribution. LabVIEW also accepts 'Beta'. This distribution takes two parameters. 
'bino' 
Specifies a binomial distribution. LabVIEW also accepts 'Binomial'. This distribution takes two parameters. 
'chi2' 
Specifies a chisquared distribution. LabVIEW also accepts 'Chisquare'. This distribution takes one parameter. 
'exp' 
Specifies an exponential distribution. LabVIEW also accepts 'Exponential'. This distribution takes one parameter. 
'f' 
Specifies an F distribution. LabVIEW also accepts 'F'. This distribution takes two parameters. 
'gam' 
Specifies a gamma distribution. LabVIEW also accepts 'Gamma'. This distribution takes two parameters. 
'geo' 
Specifies a geometric distribution. LabVIEW also accepts 'Geometric'. This distribution takes one parameter. 
'hyge' 
Specifies a hypergeometric distribution. LabVIEW also accepts 'Hypergeometric'. This distribution takes three parameters. 
'logn' 
Specifies a lognormal distribution. LabVIEW also accepts 'Lognormal'. This distribution takes two parameters. 
'nbin' 
Specifies a negative binomial distribution. LabVIEW also accepts 'Negative Binomial'. This distribution takes two parameters. 
'ncf' 
Specifies a noncentral F distribution. LabVIEW also accepts 'Noncentral F'. This distribution takes three parameters. 
'nct' 
Specifies a noncentral T distribution. LabVIEW also accepts 'Noncentral T'. This distribution takes two parameters. 
'ncx2' 
Specifies a noncentral chisquared distribution. LabVIEW also accepts 'Noncentral Chisquare'. This distribution takes two parameters. 
'norm' 
Specifies a normal distribution. LabVIEW also accepts 'Normal'. This distribution takes two parameters. 
'poiss' 
Specifies a Poisson distribution. LabVIEW also accepts 'Poisson'. This distribution takes two parameters. 
'rayl' 
Specifies a Rayleigh distribution. LabVIEW also accepts 'Rayleigh'. This distribution takes one parameter. 
't' 
Specifies a T distribution. LabVIEW also accepts 'T'. This distribution takes one parameter. 
'unid' 
Specifies a discrete uniform distribution. LabVIEW also accepts 'Discrete Uniform'. This distribution takes one parameter. 
'unif' 
Specifies a continuous uniform distribution. LabVIEW also accepts 'Uniform'. This distribution takes two parameters. 
'weib' 
Specifies a Weibull distribution. LabVIEW also accepts 'weibull'. This distribution takes two parameters. 

a 
Specifies a parameter for the distribution. a is a number or matrix. If a is a matrix, a must be of the size mbyn. Refer to the Details section for more information about this parameter. 
b 
Specifies a parameter for the distribution. b is a number or matrix. If b is a matrix, b must be of the size mbyn. Refer to the Details section for more information about this parameter. 
c 
Specifies a parameter for the distribution. c is a number or matrix. If c is a matrix, c must be of the size mbyn. Refer to the Details section for more information about this parameter. 
m 
Specifies the number of rows in r. m is a positive integer. 
n 
Specifies the number of columns in r. n is a positive integer. 
Outputs
Name 
Description 
r 
Returns an mbyn matrix of random numbers with a type distribution. 
Details
The input elements
a,
b, and
c specify the following parameters for each of the
distribution types:
 beta
 a specifies the first shape parameter.
 b specifies the second shape parameter.
 bino (Binomial)
 a specifies the number of Bernoulli trials to perform.
 b specifies the probability that a given Bernoulli trial is true.
 chi2 (Chisquare)
 a specifies the number of degrees of freedom.
 exp (Exponential)
 a specifies the scale parameter.
 f (F)
 a specifies the number of degrees of freedom in the first chisquared variate in the F distribution.
 b specifies the number of degrees of freedom in the second chisquared variate in the F distribution.
 gam (Gamma)
 a specifies the scale parameter.
 b specifies the shape parameter.
 geo (Geometric)
 a specifies the probability parameter.
 hyge (Hypergeometric)
 a specifies the total number of elements in the population.
 b specifies the number of successes.
 c specifies the number of items drawn without replacement.
 logn (Lognormal)
 a specifies the scale or median parameter.
 b specifies the shape parameter.
 nbin (Negative Binomial)
 a specifies the number of Bernoulli trials to perform.
 b specifies the probability that a given Bernoulli trial is true.
 ncf (Noncentral F)
 a specifies the number of degrees of freedom of the noncentral chisquared variate in the noncentral F distribution.
 b specifies the number of degrees of freedom of the chisquared variate in the noncentral F distribution.
 b specifies the noncentrality parameter of the noncentral chisquared variate in the noncentral F distribution.
 nct (Noncentral T)
 a specifies the number of degrees of freedom.
 b specifies the noncentrality parameter.
 ncx2 (Noncentral Chisquare)
 a specifies the number of degrees of freedom.
 b specifies the noncentrality parameter.
 norm (Normal)
 a specifies the location or mean parameter.
 b specifies the standard deviation parameter.
 poiss (Poisson)
 a specifies the mean parameter.
 rayl (Rayleigh)
 a specifies the scale parameter.
 t (T)
 a specifies the number of degrees of freedom.
 unid (Discrete Uniform)
 a specifies the amplitude parameter.
 unif (Uniform)
 a specifies the lower limit parameter.
 b specifies the upper limit parameter.
 weib (weibull)
 a specifies the location parameter.
 b specifies the shape parameter.
The following table lists the support characteristics of this function.
Supported in the LabVIEW RunTime Engine 
Yes

Supported on RT targets 
Yes

Suitable for bounded execution times on RT 
Not characterized

Examples
R = random('chi2', 3, 5, 6)
Related Topics
rand