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PPPLOT Statement |

**ALPHA=***value*-
specifies the shape parameter for P-P plots requested with the BETA and GAMMA options. For
examples, see the entries for the BETA and GAMMA options.
**ANNOTATE=***SAS-data-set***ANNO=***SAS-data-set*- [
*Graphics*]

specifies an input data set containing annotate variables as described in*SAS/GRAPH Software: Reference*. You can use this data set to add features to the plot. The ANNOTATE= data set specified in the PPPLOT statement is used for all plots created by the statement. You can also specify an ANNOTATE= data set in the PROC CAPABILITY statement to enhance all plots created by the procedure; for more information, see "ANNOTATE= Data Sets". **BETA<(***beta-options*)>-
creates a beta P-P plot. To create the plot, the
*n*nonmissing observations are ordered from smallest to largest:

The*y*-coordinate of the*i*^{ th}point is the empirical cdf value [*i*/*n*]. The*x*-coordinate is the theoretical beta cdf value

You can specify , , , and with the ALPHA=, BETA=, SIGMA=, and THETA=`where is the normalized incompletebeta function, , and lower threshold parameter scale parameter first shape parameter second shape parameter`*beta-options*, as illustrated in the following example:proc capability data=measures; ppplot width / beta(theta=1 sigma=2 alpha=3 beta=4); run;

If you do not specify values for these parameters, then by default, , , and maximum likelihood estimates are calculated for and .**IMPORTANT:**If the default unit interval (0,1) does not adequately describe the range of your data, then you should specify THETA= and SIGMA= so that your data fall in the interval .

If the data are beta distributed with parameters ,, , and , then the points on the plot for ALPHA=, BETA=, SIGMA=, and THETA=tend to fall on or near the diagonal line*y*=*x*, which is displayed by default. Agreement between the diagonal line and the point pattern is evidence that the specified beta distribution is a good fit. You can specify the SCALE= option as an alias for the SIGMA= option and the THRESHOLD= option as an alias for the THETA= option. **BETA=***value*-
specifies the shape parameter for
P-P plots requested with the BETA distribution option. See the
preceding entry for the BETA distribution option for an example.
**C=***value*-
specifies the shape parameter
*c*(*c*>0) for P-P plots requested with the WEIBULL option. See the entry for the WEIBULL option for examples. **CAXIS=***color***CAXES=***color*-
[
*Graphics*]

specifies the color for the axes. This option overrides any COLOR= specifications in an AXIS statement. The default is the first color in the device color list. **CFRAME=***color***CFR=***color*-
[
*Graphics*]

specifies a fill color for the area enclosed by the axes and frame. By default, this area is not filled. **CHREF=***color***CH=***color*-
[
*Graphics*]

specifies the color for reference lines requested by the option. The default is the first color in the device color list. **COLOR=***color*-
[
*Graphics*]

specifies the color for the diagonal reference line. For example, the following statements request a blue line:proc capability data=measures; ppplot length / normal(mu=10 sigma=0.25 color=blue); run;

The default is the first color in the device color list. **CTEXT=***color*-
[
*Graphics*]

specifies the color for tick mark values and axis labels. The default is the color specified for the CTEXT= option in the most recent GOPTIONS statement. **CVREF=***color***CV=***color*-
[
*Graphics*]

specifies the color for reference lines requested by the VREF= option. The default is the first color in the device color list. **DESCRIPTION='***string*'**DES='***string*'-
[
*Graphics*]

specifies a description, up to 40 characters, that appears in the PROC GREPLAY master menu. The default string is the variable name. **EXPONENTIAL<(***exponential-options*)>**EXP<(***exponential-options*)>-
creates an exponential P-P plot. To create the plot, the
*n*nonmissing observations are ordered from smallest to largest:

The*y*-coordinate of the*i*^{ th}point is the empirical cdf value [*i*/*n*]. The*x*-coordinate is the theoretical exponential cdf value

You can specify and with the SIGMA= and THETA=`where threshold parameter scale parameter`*exponential-options*, as illustrated in the following example:proc capability data=measures; ppplot width / exponential(theta=1 sigma=2); run;

If you do not specify values for these parameters, then by default, and a maximum likelihood estimate is calculated for .**IMPORTANT:**Your data must be greater than or equal to the lower threshold . If the default is not an adequate lower bound for your data, specify with the THETA= option.

If the data are exponentially distributed with parameters and , the points on the plot for SIGMA=and THETA= tend to fall on or near the diagonal line*y*=*x*, which is displayed by default. Agreement between the diagonal line and the point pattern is evidence that the specified exponential distribution is a good fit. You can specify the SCALE= option as an alias for the SIGMA= option and the THRESHOLD= option as an alias for the THETA= option. **FONT=***font*-
[
*Graphics*]

specifies a software font for horizontal and vertical reference line labels and axis labels. You can also specify fonts for axis labels in an AXIS statement. The FONT= font takes precedence over the FTEXT= font you specify in the GOPTIONS statement. Hardware characters are used by default. **GAMMA<(***gamma-options*)>-
creates a gamma P-P plot. To create the plot, the
*n*nonmissing observations are ordered from smallest to largest:

The*y*-coordinate of the*i*^{ th}point is the empirical cdf value [*i*/*n*]. The*x*-coordinate is the theoretical gamma cdf value

You can specify , , and with the ALPHA=, SIGMA=, and THETA=`where is the normalized incompletegamma function, and threshold parameter scale parameter shape parameter`*gamma-options*, as illustrated in the following example:proc capability data=measures; ppplot width / gamma(alpha=1 sigma=2 theta=3); run;

If you do not specify values for these parameters, then by default, and maximum likelihood estimates are calculated for and .**IMPORTANT:**Your data must be greater than or equal to the lower threshold . If the default is not an adequate lower bound for your data, specify with the THETA= option.

If the data are gamma distributed with parameters ,, and , the points on the plot for ALPHA=,SIGMA=, and THETA= tend to fall on or near the diagonal line*y*=*x*, which is displayed by default. Agreement between the diagonal line and the point pattern is evidence that the specified gamma distribution is a good fit. You can specify the SHAPE= option as an alias for the ALPHA= option, the SCALE= option as an alias for the SIGMA= option, and the THRESHOLD= option as an alias for the THETA= option.

**HAXIS=***name*-
[
*Graphics*]

specifies the name of an AXIS statement describing the horizontal axis. **HMINOR=***n***HM=***n*- [
*Graphics*]

specifies the number of minor tick marks between each major tick mark on the horizontal axis. Minor tick marks are not labeled. The default is 0. **HREF=***value-list*-
draws reference lines perpendicular to the horizontal
axis at the values specified.
See also the HREFCHAR=, CHREF=, and LHREF=options.
**HREFCHAR='***character*'-
[
*Line Printer*]

specifies the character used to form the reference lines requested by the HREF=option for a line printer. The default is the vertical bar (|). **HREFLABELS=***'label1' ... 'labeln'***HREFLABEL=***'label1' ... 'labeln'***HREFLAB=***'label1' ... 'labeln'*-
specifies labels for the reference lines requested by the
HREF=option. The number of labels must equal the number
of lines. Enclose each label in quotes. Labels can be up
to 16 characters.
**L=***linetype*- [
*Graphics*]

specifies the line type for the diagonal distribution reference line. For example,proc capability data=measures; ppplot length / normal(mu=10 sigma=0.25 l=2); run;

The default is 1, which produces a solid line. **LHREF=***linetype***LH=***linetype*- [
*Graphics*]

specifies the line type for reference lines requested by the HREF=option. The default is 2, which produces a dashed line. **LOGNORMAL<(***lognormal-options*)>**LNORM<(***lognormal-options*)>-
creates a lognormal P-P plot. To create the plot, the
*n*nonmissing observations are ordered from smallest to largest:

The*y*-coordinate of the*i*^{ th}point is the empirical cdf value [*i*/*n*]. The*x*-coordinate is the theoretical lognormal cdf value

You can specify , , and with the THETA=, ZETA=, and SIGMA=`where is the cumulative standard normaldistribution function, and threshold parameter scale parameter shape parameter`*lognormal-options*, as illustrated in the following example:proc capability data=measures; ppplot width / lognormal(theta=1 zeta=2); run;

If you do not specify values for these parameters, then by default, and maximum likelihood estimates are calculated for and .**IMPORTANT:**Your data must be greater than the lower threshold . If the default is not an adequate lower bound for your data, specify with the THETA= option.

If the data are lognormally distributed with parameters ,, and , the points on the plot for SIGMA=,THETA=, and ZETA= tend to fall on or near the diagonal line*y*=*x*, which is displayed by default. Agreement between the diagonal line and the point pattern is evidence that the specified lognormal distribution is a good fit. You can specify the SHAPE= option as an alias for the SIGMA=option, the SCALE= option as an alias for the ZETA= option, and the THRESHOLD= option as an alias for the THETA= option.

**LVREF=***linetype***LV=***linetype*- [
*Graphics*]

specifies the line type for reference lines requested by the VREF= option. The default is 2, which produces a dashed line. **MU=***value*-
specifies the mean for a normal P-P plot
requested with the NORMAL option.
For examples, see Figure 8.1,
or Figure 8.2 and Figure 8.3.
By default, the sample mean is used for .
**NAME='***string*'- [
*Graphics*]

specifies a name for the plot, up to eight characters, that appears in the PROC GREPLAY master menu. The default name is 'CAPABILI'. **NOFRAME**-
suppresses the frame around the subplot area.
**NOLINE**-
suppresses the diagonal reference line.
**NOOBSLEGEND****NOOBSL**- [
*Line Printer*]

suppresses the legend that indicates the number of hidden observations. **NORMAL<(***normal-options*)>**NORM<(***normal-options*)>-
creates a normal P-P plot. By default, if you do not specify a
distribution option, the procedure displays a normal P-P plot.
To create the plot, the
*n*nonmissing observations are ordered from smallest to largest:

The*y*-coordinate of the*i*^{ th}point is the empirical cdf value [*i*/*n*]. The*x*-coordinate is the theoretical normal cdf value

You can specify and with the MU= and SIGMA=`where is the cumulative standard normaldistribution function, and location parameter or mean scale parameter or standard deviation`*normal-options*, as illustrated in the following example:proc capability data=measures; ppplot width / normal(mu=1 sigma=2); run;

By default, the sample mean and sample standard deviation are used for and .

If the data are normally distributed with parameters and , the points on the plot for MU=and SIGMA= tend to fall on or near the diagonal line*y*=*x*, which is displayed by default. Agreement between the diagonal line and the point pattern is evidence that the specified normal distribution is a good fit. For an example, see Figure 8.1. **PPSYMBOL='***character*'- [
*Line Printer*]

specifies the character used to plot the points when the P-P plot is produced on a line printer. The default is the plus sign (+). **SCALE=***value*-
is an alias for the SIGMA= option with the BETA, EXPONENTIAL,
GAMMA, and WEIBULL options and an alias for the ZETA=
option with the LOGNORMAL option. See the entries for the
SIGMA= and ZETA= options.
**SHAPE=***value*-
is an alias for the ALPHA= option with the GAMMA option, for the
SIGMA= option with the LOGNORMAL option, and for the C= option
with the WEIBULL option. See the entries for the ALPHA=, C=,
and SIGMA= options.
**SIGMA=***value*-
specifies the parameter , where .When used with the BETA,
EXPONENTIAL, GAMMA, NORMAL,
and WEIBULL options, the SIGMA= option specifies the scale parameter.
When used with the LOGNORMAL option, the SIGMA= option specifies
the shape parameter. For an example of the SIGMA= option
used with the NORMAL option, see Figure 8.1.
**SQUARE**-
displays the P-P plot in a square frame. The default is a
rectangular frame. See Figure 8.1
for an example.
**SYMBOL='***character*'- [
*Line Printer*]

specifies the character used to plot the diagonal reference line for a line printer. The default character is the first letter of the distribution option keyword. **THETA=***value*-
specifies the lower threshold parameter for plots
requested with the BETA, EXPONENTIAL, GAMMA, LOGNORMAL, and
WEIBULL options.
**THRESHOLD=***value*-
is an alias for the THETA= option.
**VAXIS=***name*- [
*Graphics*]

specifies the name of an AXIS statement describing the vertical axis. For an example, see Figure 8.2 and Figure 8.3. **VMINOR=***n***VM=***n*- [
*Graphics*]

specifies the number of minor tick marks between each major tick mark on the vertical axis. Minor tick marks are not labeled. The default is 0. **VREF=***value-list*-
draws reference lines perpendicular to the vertical
axis at the values specified.
See the entries for the VREFCHAR=, CVREF=, and LVREF= options.
**VREFCHAR='***character*'-
[
*Line Printer*]

specifies the character used to form the reference lines requested by the VREF= option for a line printer. The default is the hyphen (-). **VREFLABELS='***label1' ... 'labeln'***VREFLABEL='***label1' ... 'labeln'***VREFLAB='***label1' ... 'labeln'*-
specifies labels for the reference lines requested by the
VREF= option. The number of labels must equal the number
of lines. Enclose each label in quotes. Labels can be up
to 16 characters.
**W=***n*- [
*Graphics*]

specifies the width in pixels for the diagonal reference line. Specify the W= option in parentheses following a distribution option keyword. For a similar syntax example, see the entry for the L= option. The default is 1. **WEIBULL<(***Weibull-options*)>**WEIB<(***Weibull-options*)>-
creates a Weibull P-P plot. To create the plot, the
*n*nonmissing observations are ordered from smallest to largest:

The*y*-coordinate of the*i*^{ th}point is the empirical cdf value [*i*/*n*]. The*x*-coordinate is the theoretical Weibull cdf value

You can specify`where threshold parameter scale parameter`*c*= shape parameter (*c*>0)*c*, , and with the C=, SIGMA=, and THETA=*Weibull-options*, as illustrated in the following example:proc capability data=measures; ppplot width / weibull(theta=1 sigma=2); run;

If you do not specify values for these parameters, then by default and maximum likelihood estimates are calculated for and*c*.**IMPORTANT:**Your data must be greater than or equal to the lower threshold . If the default is not an adequate lower bound for your data, you should specify with the THETA= option.

If the data are Weibull distributed with parameters*c*, , and , the points on the plot for C=*c*, SIGMA=, and THETA= tend to fall on or near the diagonal line*y*=*x*, which is displayed by default. Agreement between the diagonal line and the point pattern is evidence that the specified Weibull distribution is a good fit. You can specify the SHAPE= option as an alias for the C= option, the SCALE= option as an alias for the SIGMA= option, and the THRESHOLD= option as an alias for the THETA= option. **ZETA=***value*-
specifies a value for the scale parameter for lognormal
P-P plots requested with the LOGNORMAL option.

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Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.