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

GL2CDF

Name:
    GL2CDF (LET)
Type:
    Library Function
Purpose:
    Compute the type 2 generalized logistic cumulative distribution function with shape parameter alpha.
Description:
    The standard form of the type 2 generalized logistic distribution has the cumulative distribution function:

      F(x;alpha) = 1 - EXP(-alpha*x)/(1 + EXP(-x))**(alpha)    alpha > 0

    The general form of the type 2 generalized logistic cumulative distribution function can be obtained by replacing x in the above formula with (x-loc)/scale.

Syntax:
    LET <y> = GL2CDF(<x>,<alpha>,<loc>,<scale>)
                            <SUBSET/EXCEPT/FOR qualification>
    where <x> is a variable, number or parameter;
                <alpha> is a number or parameter that specifies the value of the shape parameter;
                <loc> is a number or parameter that specifies the value of the location parameter;
                <scale> is a 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 generalized logistic type 2 cdf value is stored;
    and where the <SUBSET/EXCEPT/FOR qualification> is optional.

    The location and scale parameters are optional.

Examples:
    LET A = GL2CDF(3,2)
    LET X2 = GL2CDF(X1,ALPHA)
    PLOT GL2CDF(X,ALPHA) FOR X = -5 0.01 5
Default:
    None
Synonyms:
    None
Related Commands:
    GL2PDF = Compute the generalized logistic type 2 probability density function.
    GL2PPF = Compute the generalized logistic type 2 percent point function.
    GLOPDF = Compute the generalized logistic type 1 probability density function.
    GL3PDF = Compute the generalized logistic type 3 probability density function.
    GL4PDF = Compute the generalized logistic type 4 probability density function.
    GL5PDF = Compute the generalized logistic (Hosking parameterization) probability density function.
    LOGPDF = Compute the logistic probability density function.
    NORPDF = Compute the normal probability density function.
    LGNPDF = Compute the logmormal probability density function.
Reference:
    "Continuous Univariate Distributions - 2", 2nd. Ed., Johnson, Kotz, and Balakrishnan, John Wiley, 1994 (pp. 140-147).
Applications:
    Distributional Modeling
Implementation Date:
    2006/3
Program:
     
    LET A = DATA 0.5  1  2  5
    MULTIPLOT 2 2
    MULTIPLOT CORNER COORDINATES 0 0 100 95
    MULTIPLOT SCALE FACTOR 2
    LABEL CASE ASIS
    TITLE CASE ASIS
    TITLE DISPLACEMENT 2
    X1LABEL X
    Y1LABEL Probability
    X1LABEL DISPLACEMENT 12
    Y1LABEL DISPLACEMENT 15
    .
    LOOP FOR K = 1 1 4
       LET ALPHA = A(K)
       TITLE Alpha = ^ALPHA
       PLOT GL2CDF(X,ALPHA) FOR X = -5  0.01  5
    END OF LOOP
    END OF MULTIPLOT
    CASE ASIS
    MOVE 50 97
    JUSTIFICATION CENTER
    TEXT Generalized Logistic Type 2 CDF's
        
    plot generated by sample program

Date created: 3/27/2006
Last updated: 3/27/2006
Please email comments on this WWW page to alan.heckert@nist.gov.