Chapter Contents
Chapter Contents
Previous
Previous
Next
Next
INSET Statement

Summary of INSET Keywords

Summary Statistics and Process Capability Indices

Table 5.1: Summary Statistics
Nsample size
SUMWGTsum of the weights
MEANsample mean
SUMsum of the observations
STDstandard deviation
VARvariance
SKEWNESSskewness
KURTOSISkurtosis
MAXlargest value
MINsmallest value
NOBSnumber of observations
RANGErange
MODEmost frequent value
NMISSnumber of missing values
USSuncorrected sum of squares
CSScorrected sum of squares
CVcoefficient of variation
STDMEANstandard error of the mean
DATA=arbitrary values from SAS-data-set

Table 5.2: Percentile Statistics
P11 st percentile
P55 th percentile
P1010 th percentile
Q1lower quartile (25 th percentile)
MEDIANmedian (50 th percentile)
Q3upper quartile (75 th percentile)
P9090 th percentile
P9595 th percentile
P9999 th percentile
QRANGEinterquartile range (Q3 - Q1)

Table 5.3: Test of Normality
NORMALTESTtest statistic for normality
PNORMALprobability value for the normality test

Table 5.4: Signed Rank Test
SIGNRANKsigned rank statistic
PROBSprobability value for the signed rank test

Table 5.5: Capability Indices and Confidence Limits
CPcapability index Cp
CPLCLlower confidence limit for Cp
CPUCLupper confidence limit for Cp
CPKcapability index Cpk
CPKLCLlower confidence limit for Cpk
CPKUCLupper confidence limit for Cpk
CPLcapability index CPL
CPMcapability index Cpm
CPMLCLlower confidence limit for Cpm
CPMUCLupper confidence interval for Cpm
CPUcapability index CPU
Kcapability index K

Table 5.6: Specification Limits and Related Information
LSLlower specification limit
USLupper specification limit
TARGETtarget value
PCTGTRpercent of nonmissing observations that exceed the upper specification limit
PCTLSSpercent of nonmissing observations that are less than the lower specification limit
PCTBETpercent of nonmissing observations between the upper and lower specification limits (inclusive)

Table 5.7: Student's t-Test
Tstatistic for Student's t-test
PROBTprobability value for Student's t-test

Statistics Available with Parametric Density Estimates

You can request parametric density estimates with all plot statements in the CAPABILITY procedure (CDFPLOT, COMPHISTOGRAM, HISTOGRAM, PPPLOT, PROBPLOT, and QQPLOT). You can display parameters and statistics associated with these estimates in an inset by specifying a distribution keyword followed by secondary keywords in parentheses. For example, the following statements create a histogram for STRENGTH with a fitted exponential density curve:
   proc capability data=wire;
      histogram strength / exp;
      inset exp(sigma theta);
   run;
The secondary keywords SIGMA and THETA for the EXP distribution keyword request an inset displaying the values of the exponential scale parameter \sigmaand threshold parameter \theta. You must request the distribution option in the plot statement to display the corresponding distribution statistics in an inset. Specifying a distribution keyword with no secondary keywords produces an inset displaying the full set of parameters for that distribution. See Output 5.1.1 for an example of an inset with statistics from a fitted normal curve.

The following table describes the available distribution keywords. Note that some keywords are not available with all plot statements.

Table 5.8: Density Estimation Primary Keywords
Keyword Distribution Plot Statement Availability
BETAbetaall except COMPHISTOGRAM
EXPONENTIALexponentialall except COMPHISTOGRAM
GAMMAgammaall except COMPHISTOGRAM
LOGNORMALlognormalall except COMPHISTOGRAM
NORMALnormalall plot statements
SBJohnson SBall except COMPHISTOGRAM
SUJohnson SUall except COMPHISTOGRAM
WEIBULLWeibullall except COMPHISTOGRAM
WEIBULL22-parameter WeibullPROBPLOT and QQPLOT

Table 5.9 through Table 5.17 list the secondary keywords available with each distribution keyword listed in Table 5.8. In many cases, aliases can be used (for example, ALPHA in place of SHAPE1).

Table 5.9: Secondary Keywords Available with the BETA Keyword
Secondary Keyword Alias Description
ALPHASHAPE1first shape parameter \alpha
BETASHAPE2second shape parameter \beta
SIGMASCALEscale parameter \sigma
THETATHRESHOLDlower threshold parameter \theta

Table 5.10: Secondary Keywords Available with the EXP Keyword
Secondary Keyword Alias Description
SIGMASCALEscale parameter \sigma
THETATHRESHOLDthreshold parameter \theta

Table 5.11: Secondary Keywords Available with the GAMMA Keyword
Secondary Keyword Alias Description
ALPHASHAPEshape parameter \alpha
SIGMASCALEscale parameter \sigma
THETATHRESHOLDthreshold parameter \theta

Table 5.12: Secondary Keywords Available with the LOGNORMAL Keyword
Secondary Keyword Alias Description
SIGMASHAPEshape parameter \sigma
THETATHRESHOLDthreshold parameter \theta
ZETASCALEscale parameter \zeta

Table 5.13: Secondary Keywords Available with the NORMAL Keyword
Secondary Keyword Alias Description
MUMEANmean parameter \mu
SIGMASTDscale parameter \sigma

Table 5.14: Secondary Keywords Available with the SB Keyword
Secondary Keyword Alias Description
DELTA shape parameter \delta
GAMMA shape parameter \gamma
SIGMASHAPEscale parameter \sigma
THETATHRESHOLDthreshold parameter \theta

Table 5.15: Secondary Keywords Available with the SU Keyword
Secondary Keyword Alias Description
DELTA shape parameter \delta
GAMMA shape parameter \gamma
SIGMASHAPEscale parameter \sigma
THETA location parameter \theta

Table 5.16: Secondary Keywords Available with the WEIBULL Keyword
Secondary Keyword Alias Description
CSHAPEshape parameter c
SIGMASCALEscale parameter \sigma
THETATHRESHOLDthreshold parameter \theta

Table 5.17: Secondary Keywords Available with the WEIBULL2 Keyword
Secondary Keyword Alias Description
CSHAPEshape parameter c
SIGMASCALEscale parameter \sigma
THETATHRESHOLDknown lower threshold \theta_0

The secondary keywords listed in Table 5.18 can be used with any distribution keyword but only with the HISTOGRAM and COMPHISTOGRAM plot statements.

Table 5.18: Statistics Computed from Any Parametric Density Estimate
Secondary Keyword Description
CPcapability index Cp
CPKcapability index Cpk
CPLcapability index CPL
CPMcapability index Cpm
CPUcapability index CPU
ESTPCTLSSestimated percentage less than the lower specification limit
ESTPCTGTRestimated percentage greater than the upper specification limit
Kcapability index K

The secondary keywords listed in Table 5.19 can be used with any distribution keyword but only with the HISTOGRAM plot statement (see Example 5.1).

Table 5.19: Goodness-of-Fit Statistics for Fitted Curves
Secondary Keyword Description
CHISQchi-square statistic
DFdegrees of freedom for the chi-square test
PCHISQprobability value for the chi-square test
ADAnderson-Darling EDF test statistic
ADPVALAnderson-Darling EDF test p-value
CVMCram\acute{e}r-von Mises EDF test statistic
CVMPVALCram\acute{e}r-von Mises EDF test p-value
KSDKolmogorov-Smirnov EDF test statistic
KSDPVALKolmogorov-Smirnov EDF test p-value

Table 5.20 lists primary keywords available only with the HISTOGRAM and COMPHISTOGRAM plot statements. These keywords display fill areas on a histogram. If you fit a parametric density on a histogram and request that the area under the curve be filled, these keywords display the percentage of the distribution area that lies below the lower specification limit, between the specification limits, or above the upper specification limit. If you do not fill the area beneath a parametric density estimate, these keywords display the observed proportion of observations (that is, the area in the bars of the histogram).

You should use these options with the FILL, CFILL=, and PFILL= options in the HISTOGRAM and COMPHISTOGRAM statements and with the CLEFT=, CRIGHT=, PLEFT=, and PRIGHT= options in the SPEC statements. See Output 5.2.1 for an example.

Table 5.20: Curve Area Keywords
Keyword Alias Description
BETWEENPCTBETPCTarea between the specification limits
LSLPCT area below the lower specification limit
USLPCT area above the upper specification limit

Statistics Available with Nonparametric Kernel Density Estimates

You can request nonparametric kernel density estimates with the HISTOGRAM and COMPHISTOGRAM plot statements. You can display statistics associated with these estimates by specifying a kernel density keyword followed by secondary keywords in parentheses. For example, the following statements create a histogram for STRENGTH with a fitted kernel density estimate:
   proc capability data=wire;
      histogram strength / kernel;
      inset kernel(c amise);
   run;


The secondary keywords C and AMISE for the KERNEL keyword display the values of the standardized bandwidth c and the approximate mean integrated square error.

Note that you can specify up to five kernel density estimates on a single histogram. If you specify multiple kernel density estimates, you can request inset statistics for all of the estimates with the KERNEL keyword, or you can display inset statistics for individual curves with KERNELn keywords, as in the following example:

   proc capability data=wire;
      histogram strength / kernel(c = 1 2 3);
      inset kernel2(c) kernel3(c);
   run;

Three kernel density estimates are displayed on the histogram, but the inset displays the value of c only for the second and third estimates.

Table 5.21 lists the kernel density keywords. Table 5.22 lists the available secondary keywords.

Table 5.21: Kernel Density Estimate Primary Keywords
Keyword Description
KERNELdisplays statistics for all kernel estimates
KERNELndisplays statistics for only the n th kernel density estimate
 n = 1, 2, 3, 4, or 5

Table 5.22: Secondary Keywords Available with the KERNEL Keyword
Secondary Keyword Description
TYPEkernel type: normal, quadratic, or triangular
BANDWIDTHbandwidth \lambda for the density estimate
BWIDTHalias for BANDWIDTH
Cstandardized bandwidth c for the density estimate:
 c=\frac{\lambda}Q n^{\frac{1}5} where n= sample size, \lambda= bandwidth, and
 Q= interquartile range
AMISEapproximate mean integrated square error (MISE) for the
 kernel density

Chapter Contents
Chapter Contents
Previous
Previous
Next
Next
Top
Top

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