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Dataplot Vol 2 Vol 1

SLOCDF

Name:
    SLOCDF (LET)
Type:
    Library Function
Purpose:
    Compute the slope cumulative distribution function with shape parameter alpha.
Description:
    The standard slope distribution has the following cumulative distribution function:

      F(x;alpha) = alpha*x + (1-alpha)*x**2    0 <= x <= 1, 0 <= alpha <= 2

    with alpha denoting the shape parameter.

    This distribution can be extended with lower and upper bound parameters. If a and b denote the lower and upper bounds, respectively, then the location and scale parameters are:

      location = a
      scale = b - a

    The general form of the distribution can then be found by using the relation

      F(x;alpha,a,b) = F((x-a)/(b-a);alpha,0,1)
Syntax:
    LET <y> = SLOCDF(<x>,<alpha>,<a>,<b>)
                            <SUBSET/EXCEPT/FOR qualification>
    where <x> is a number, parameter, or variable containing values in the interval (a,b);
                <y> is a variable or a parameter (depending on what <x> is) where the computed slope cdf value is stored;
                <alpha> is a positive number, parameter, or variable that specifies the shape parameter;
                <a> is a number, parameter, or variable that specifies the lower limit;
                <b> is a number, parameter, or variable that specifies the upper limit;
    and where the <SUBSET/EXCEPT/FOR qualification> is optional.

    If <a> and <b> are omitted, they default to 0 and 1, respectively.

Examples:
    LET A = SLOCDF(0.3,0.2)
    LET Y = SLOCDF(X,0.5,0,5)
    PLOT SLOCDF(X,2,0,3) FOR X = 0 0.01 3
Default:
    None
Synonyms:
    None
Related Commands:
    SLOPDF = Compute the slope probability density function.
    SLOPPF = Compute the slope percent point function.
    TSSPDF = Compute the two-sided slope probability density function.
    OGIPDF = Compute the ogive probability density function.
    TOPPDF = Compute the Topp and Leone probability density function.
    RGTPDF = Compute the generalized reflected slope probability density function.
    GTLPDF = Compute the generalized slope probability density function.
    TSPPDF = Compute the two-sided power probability density function.
    BETPDF = Compute the alpha probability density function.
    TRIPDF = Compute the triangular probability density function.
    TRAPDF = Compute the trapezoid probability density function.
    UNIPDF = Compute the uniform probability density function.
    POWPDF = Compute the power probability density function.
    JSBPDF = Compute the Johnson SB probability density function.
Reference:
Applications:
    Distributional Modeling
Implementation Date:
    2007/10
Program:
     
     LABEL CASE ASIS
     TITLE CASE ASIS
     TITLE OFFSET 2
     .
     MULTIPLOT 2 2
     MULTIPLOT CORNER COORDINATES 0 0 100 95
     MULTIPLOT SCALE FACTOR 2
     .
     LET ALPHA  = 0.5
     TITLE Alpha = ^alpha
     PLOT SLOCDF(X,ALPHA) FOR X = 0  0.01  1
     .
     LET ALPHA  = 1
     TITLE Alpha = ^alpha
     PLOT SLOCDF(X,ALPHA) FOR X = 0  0.01  1
     .
     LET ALPHA  = 1.5
     TITLE Alpha = ^alpha
     PLOT SLOCDF(X,ALPHA) FOR X = 0  0.01  1
     .
     LET ALPHA  = 2
     TITLE Alpha = ^alpha
     PLOT SLOCDF(X,ALPHA) FOR X = 0  0.01  1
     .
     END OF MULTIPLOT
     .
     JUSTIFICATION CENTER
     MOVE 50 97
     TEXT Slope Cumulative Distribution Functions
        
    plot generated by sample program

Date created: 11/07/2007
Last updated: 11/07/2007
Please email comments on this WWW page to alan.heckert@nist.gov.