SED navigation bar go to SED home page go to Dataplot home page go to NIST home page SED Home Page SED Staff SED Projects SED Products and Publications Search SED Pages
Dataplot Vol 2 Vol 1

RAYCDF

Name:
    RAYCDF (LET)
Type:
    Library Function
Purpose:
    Compute the Rayleigh cumulative distribution function.
Description:
    The Rayleigh distribution is a special case of the chi distribution with degrees of freedom parameter = 2 and scale parameter sigma. It is also a special case of the Weibull distribution with shape parameter = 2 and scale parameter = SQRT(2)*sigma. Note that some sources may define the Rayleigh distribution as a Weibull with shape parameter = 2 and scale parameter = sigma.

    The Rayleigh distribution has the following cumulative disribution function:

      F(x,u,sigma)=1 - EXP(-(1/2)*((x-u)/sigma)**2)
 x > u, sigma > 0

    with mu and sigma denoting the location and scale parameters, respectively.

    The standard Rayleigh distribution is the case with mu = 0 and sigma = 1.

Syntax:
    LET <y> = RAYCDF(<x>,<loc>,<scale>)
                            <SUBSET/EXCEPT/FOR qualification>
    where <x> is a variable or a parameter;
                <loc> is an optional number or parameter that specifies the value of the location parameter;
                <scale> is an optional positive number or parameter that specifies the value of the scale parameter;
                <y> is a variable or a parameter (depending on what <x> is) where the computed Rayleigh cdf value is stored;
    and where the <SUBSET/EXCEPT/FOR qualification> is optional.
Examples:
    LET Y = RAYCDF(3)
    LET Y = RAYCDF(X1,0,SIGMA)
    PLOT RAYCDF(X,0,SIGMA) FOR X = 0.01 0.01 5
Default:
    None
Synonyms:
    None
Related Commands:
    RAYPDF = Compute the Rayleigh probability density function.
    RAYPPF = Compute the Rayleigh percent point function.
    MAXPDF = Compute the Maxwell probability density function.
    CHPDF = Compute the chi probability density function.
    WEIPDF = Compute the Weibull probability density function.
    NORPDF = Compute the normal probability density function.
    LGNPDF = Compute the lognormal probability density function.
Reference:
    "Continuous Univariate Distributions: Volume I", Second Edition, Johnson, Kotz, and Balakrishnan, Wiley, 1994, pp. 453, 686.
Applications:
    Distributional Modeling, Statistical Physics
Implementation Date:
    6/2004
Program:
     
    Y1LABEL Probability
    X1LABEL X
    LABEL CASE ASIS
    TITLE CASE ASIS
    TITLE Rayleigh Cumulative Disribution
    PLOT RAYCDF(X) FOR X = 0  0.01  5
        
    plot generated by sample program

Date created: 7/7/2004
Last updated: 7/7/2004
Please email comments on this WWW page to alan.heckert@nist.gov.