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Dataplot Vol 2 Vol 1

B10PDF

Name:
    B10PDF (LET)
Type:
    Library Function
Purpose:
    Compute the Burr type 10 probability density function with shape parameter r.
Description:
    The standard Burr type 10 distribution has the following probability density function:

      f(x;r) = 2*r*x*(1 - EXP(-x**2)**(r-1)/EXP(x^2)      x >  0; r > 0

    with r denoting the shape parameter.

    This distribution can be generalized with location and scale parameters in the usual way using the relation

      f(x;r,loc,scale) = (1/scale)*f((x-loc)/scale,0,1)

    If r = 1, the Burr type 10 distribution is equivalent to the Rayleigh distribution. For this reason, the Burr type 10 distribution is also referred to as the generalized Rayleigh distribution. It has found use in reliability applications.

Syntax:
    LET <y> = B10PDF(<x>,<r>,<loc>,<scale>)
                            <SUBSET/EXCEPT/FOR qualification>
    where <x> is a number, parameter, or variable;
                <y> is a variable or a parameter (depending on what <x> is) where the computed Burr type 10 pdf value is stored;
                <r> is a positive number, parameter, or variable that specifies the shape parameter;
                <loc> is a number, parameter, or variable that specifies the location parameter;
                <scale> is a positive number, parameter, or variable that specifies the scale parameter;
    and where the <SUBSET/EXCEPT/FOR qualification> is optional.

    If <loc> and <scale> are omitted, they default to 0 and 1, respectively.

Examples:
    LET A = B10PDF(0.3,0.2)
    LET Y = B10PDF(X,0.5,0,5)
    PLOT B10PDF(X,2,0,3) FOR X = 0 0.01 5
Note:
    Burr type 10 random numbers, probability plots, and goodness of fit tests can be generated with the commands:

      LET R = <value>
      LET Y = BURR TYPE 10 RANDOM NUMBERS FOR I = 1 1 N
      BURR TYPE 10 PROBABILITY PLOT Y
      BURR TYPE 10 PROBABILITY PLOT Y2 X2
      BURR TYPE 10 PROBABILITY PLOT Y3 XLOW XHIGH
      BURR TYPE 10 KOLMOGOROV SMIRNOV GOODNESS OF FIT Y
      BURR TYPE 10 CHI-SQUARE GOODNESS OF FIT Y2 X2
      BURR TYPE 10 CHI-SQUARE GOODNESS OF FIT Y3 XLOW XHIGH

    The following commands can be used to estimate the r shape parameter for the Burr type 10 distribution:

      LET R1 = <value>
      LET R2 = <value>
      BURR TYPE 10 PPCC PLOT Y
      BURR TYPE 10 PPCC PLOT Y2 X2
      BURR TYPE 10 PPCC PLOT Y3 XLOW XHIGH
      BURR TYPE 10 KS PLOT Y
      BURR TYPE 10 KS PLOT Y2 X2
      BURR TYPE 10 KS PLOT Y3 XLOW XHIGH

    The default values for R1 and R2 are 0.5 and 10.

    The probability plot can then be used to estimate the location and scale (location = PPA0, scale = PPA1).

    The 2-parameter Burr type 10 maximum likelihood estimates can be obtained using the command

      BURR TYPE 10 MAXIMUM LIKELIHOOD Y

    The maximum likelihood estimates are obtained as the solution of the following simultaneous equations (from Raqab and Kundu):

      (n/r) + SUM[i=1 to n][LN(1 - EXP(-(s*x(i))**2))] = 0

      (2*n/s) - 2*s*SUM[i=1 to n][x(i)**2] + 
2*s*(r-1)*SUM[i=1 to n][x(i)^2*EXP(-(s*x(i))**2)/
1 - EXP(-(s*x(i))**2))] = 0

    The BOOTSTRAP DISTRIBUTION command can be used to find uncertainty intervals for the parameter estimates based on the ppcc plot, the ks plot, and the maximum likelihood estimates.

Default:
    None
Synonyms:
    BURR TYPE X is a synonym for BURR TYPE 10.
Related Commands:
    B10CDF = Compute the Burr type 10 cumulative distribution function.
    B10PPF = Compute the Burr type 10 percent point function.
    BU2PDF = Compute the Burr type 2 probability density function.
    BU3PDF = Compute the Burr type 3 probability density function.
    BU4PDF = Compute the Burr type 4 probability density function.
    BU5PDF = Compute the Burr type 5 probability density function.
    BU5PDF = Compute the Burr type 6 probability density function.
    BU7PDF = Compute the Burr type 7 probability density function.
    BU8PDF = Compute the Burr type 8 probability density function.
    BU9PDF = Compute the Burr type 9 probability density function.
    B11PDF = Compute the Burr type 11 probability density function.
    B12PDF = Compute the Burr type 12 probability density function.
    RAYPDF = Compute the Rayleigh probability density function.
    WEIPDF = Compute the Weibull probability density function.
    EWEPDF = Compute the exponentiated Weibull probability density function.
Reference:
    Burr (1942), "Cumulative Frequency Functions", Annals of Mathematical Statistics, 13, pp. 215-232.

    Raqab and Kundu (2006), "Burr Type X Distributions: Revisited", Journal of Probability and Statistical Sciences, Vol. 4, No. 2, pp. 179-193.

    Johnson, Kotz, and Balakrishnan (1994), "Contiunuous Univariate Distributions--Volume 1", Second Edition, Wiley, pp. 53-54.

    Devroye (1986), "Non-Uniform Random Variate Generation", Springer-Verlang, pp. 476-477.

Applications:
    Distributional Modeling
Implementation Date:
    2007/10
Program 1:
     
    LABEL CASE ASIS
    TITLE CASE ASIS
    TITLE OFFSET 2
    .
    MULTIPLOT 2 2
    MULTIPLOT CORNER COORDINATES 0 0 100 95
    MULTIPLOT SCALE FACTOR 2
    .
    LET R  = 0.5
    TITLE R = ^r
    PLOT B10PDF(X,R) FOR X = 0.01  0.01  5
    .
    LET R  = 1
    TITLE R = ^r
    PLOT B10PDF(X,R) FOR X = 0.01  0.01  5
    .
    LET R  = 2
    TITLE R = ^r
    PLOT B10PDF(X,R) FOR X = 0.01  0.01  5
    .
    LET R  = 5
    TITLE R = ^r
    PLOT B10PDF(X,R) FOR X = 0.01  0.01  5
    .
    END OF MULTIPLOT
    .
    JUSTIFICATION CENTER
    MOVE 50 97
    TEXT Burr Type 10 Probability Density Functions
        
    plot generated by sample program

Program 2:
     
    let r = 2.1
    let rsav = r
    .
    let y = burr type 10 random numbers for i = 1 1 200
    let y = 10*y
    let amax = maximum y
    .
    burr type 10 ppcc plot y
    let rtemp = shape - 2
    let r1 = max(rtemp,0.05)
    let r2 = shape + 2
    y1label Correlation Coefficient
    x1label R
    burr type 10 ppcc plot y
    let r = shape
    justification center
    move 50 6
    text Rhat = ^r (R = ^rsav)
    move 50 2
    text Maximum PPCC = ^maxppcc
    .
    char x
    line bl
    burr type 10 prob plot y1
    move 50 6
    text Location = ^ppa0, Scale = ^ppa1
    char bl
    line so
    .
    relative hist y
    limits freeze
    pre-erase off
    plot b10pdf(x,r,ppa0,ppa1) for x = 0.01 .01 amax
    limits 
    pre-erase on
    .
    let ksloc = ppa0
    let ksscale = ppa1
    burr type 10 kolmogorov smirnov goodness of fit y
    .
    burr type 10 mle y
    let ksloc = 0
    let ksscale = scaleml
    let r = rml
    burr type 10 kolmogorov smirnov goodness of fit y
        
    plot generated by sample program

    plot generated by sample program

    plot generated by sample program

    plot generated by sample program

                       KOLMOGOROV-SMIRNOV GOODNESS-OF-FIT TEST
      
     NULL HYPOTHESIS H0:      DISTRIBUTION FITS THE DATA
     ALTERNATE HYPOTHESIS HA: DISTRIBUTION DOES NOT FIT THE DATA
     DISTRIBUTION:            BURR TYPE 10
        NUMBER OF OBSERVATIONS              =      200
      
     TEST:
     KOLMOGOROV-SMIRNOV TEST STATISTIC      =   0.3035629E-01
      
        ALPHA LEVEL         CUTOFF              CONCLUSION
                10%       0.086*              ACCEPT H0
                          0.085**
                 5%       0.096*              ACCEPT H0
                          0.095**
                 1%       0.115*              ACCEPT H0
                          0.114**
      
         *  - STANDARD LARGE SAMPLE APPROXIMATION  ( C/SQRT(N) )
        ** - MORE ACCURATE LARGE SAMPLE APPROXIMATION  ( C/SQRT(N + SQRT(N/10)) )
      
      
                 BURR TYPE 10 PARAMETER ESTIMATION
      
     SUMMARY STATISTICS:
     NUMBER OF OBSERVATIONS                   =      200
     SAMPLE MEAN                              =    12.03479
     SAMPLE STANDARD DEVIATION                =    4.367350
     SAMPLE MINIMUM                           =    2.148263
     SAMPLE MAXIMUM                           =    24.75311
      
     MAXIMUM LIKELIHOOD ESTIMATES:
     ESTIMATE OF R                            =    2.141123
     ESTIMATE OF SCALE                        =   -10.27274
      
      
                       KOLMOGOROV-SMIRNOV GOODNESS-OF-FIT TEST
      
     NULL HYPOTHESIS H0:      DISTRIBUTION FITS THE DATA
     ALTERNATE HYPOTHESIS HA: DISTRIBUTION DOES NOT FIT THE DATA
     DISTRIBUTION:            BURR TYPE 10
        NUMBER OF OBSERVATIONS              =      200
      
     TEST:
     KOLMOGOROV-SMIRNOV TEST STATISTIC      =   0.9947237
      
        ALPHA LEVEL         CUTOFF              CONCLUSION
                10%       0.086*              REJECT H0
                          0.085**
                 5%       0.096*              REJECT H0
                          0.095**
                 1%       0.115*              REJECT H0
                          0.114**
      
         *  - STANDARD LARGE SAMPLE APPROXIMATION  ( C/SQRT(N) )
        ** - MORE ACCURATE LARGE SAMPLE APPROXIMATION  ( C/SQRT(N + SQRT(N/10)) )
        

Date created: 11/27/2007
Last updated: 11/27/2007
Please email comments on this WWW page to alan.heckert@nist.gov.