Chapter Contents 
Previous 
Next 
HISTOGRAM Statement 
The following entries provide detailed descriptions of options for the HISTOGRAM statement.
where and
lower threshold parameter (lower endpoint parameter) scale parameter shape parameter shape parameter h = width of histogram interval
proc capability; histogram length / beta(theta=50 sigma=25); run;
proc capability; histogram length / kernel(c=0.5 1.0 mise); run;
proc capability; histogram length / kernel(c=1 2 3 k=normal quadratic); run;
where
threshold parameter scale parameter h = width of histogram interval
proc capability; histogram / exponential(theta=10 l=2 color=red); run;
proc capability; histogram length / normal(fill) cfill=green pfill=solid; run;Depending on the area to be filled (outside or between the specification limits), you can specify the color and pattern with options in the SPEC statement and HISTOGRAM statement, as summarized in the following table:
Area Under Curve  Statement  Option 
between specification  HISTOGRAM  CFILL=color 
limits  HISTOGRAM  PFILL=pattern 
left of lower  SPEC  CLEFT=color 
specification limit  SPEC  PLEFT=pattern 
right of upper  SPEC  CRIGHT=color 
specification limit  SPEC  PRIGHT=pattern 
where
threshold parameter
scale parameter
shape parameter
h = width of histogram interval
The parameter for the gamma distribution
must be less than the minimum data value. You can
specify with the THETA= gammaoption.
The default value for is 0.
If you specify THETA=EST, a maximum likelihood estimate
is computed for .In addition,
the gamma distribution has a shape parameter and a scale parameter . You can specify these
parameters with the ALPHA= and SIGMA= gammaoptions.
By default, maximum likelihood estimates are computed
for and . For example, the following
statements fit a gamma curve with and with maximum
likelihood estimates for and :proc capability; histogram length / gamma(theta=4); run;Note that the maximum likelihood estimate of is calculated iteratively using the NewtonRaphson approximation. The ALPHADELTA=, ALPHAINITIAL=, and MAXITER= gammaoptions control the approximation.
proc capability; histogram length / kernel(k=quadratic); run;
proc capability; histogram length / kernel(c=0.5 1.0 1.5 k=normal quadratic); run;
FILL  specifies that the area under the curve is to be filled 
COLOR=  specifies the color of the curve 
L=  specifies the line style for the curve 
W=  specifies the width of the curve 
K=  specifies the type of kernel function 
C=  specifies the smoothing parameter 
SYMBOL=  specifies the character used to plot the kernel density curve if the histogram is produced on a line printer 
whereNote that the lognormal distribution is also referred to as the S_{L} distribution in the Johnson system of distributions.
threshold parameter scale parameter shape parameter h = width of histogram interval
proc capability; histogram length / lognormal; run;The LOGNORMAL option can appear only once in a HISTOGRAM statement. Table 4.2 and Table 4.6 list options that you can specify with the LOGNORMAL option. See Example 4.2 and "Formulas for Fitted Curves".
proc capability; histogram length / gamma(theta=3 midpercents) run;
midpoints=2 to 10 by 0.5then all of the observations and specification limits must fall between 1.75 and 10.25 (otherwise, a default list of midpoints is used).
proc capability; histogram length / midpoints=20 to 80 by 10 haxis=axis1; axis1 length=6 in order=10 20 30 40 50 60 70 80 90; run;
where
mean
standard deviation
h = width of histogram interval
Note that the normal distribution is also referred to as
the S_{N} distribution in the Johnson system of distributions.
proc capability; histogram length / normal(mu=14 sigma=0.05); run;
proc capability; histogram length / lognormal(percents=1 3 5 95 97 99); run;

where
threshold parameter
scale parameter
shape parameter
shape parameter
h = width of histogram interval
The S_{B} distribution is bounded below by the parameter
and above by the value .The parameter
must be less than the minimum data value. You can
specify with the THETA= S_{B}option,
or you can request that be estimated
with the THETA = EST S_{B}option.
The default value for is zero.
The sum must be greater than the maximum
data value.
The default value for is one.
You can specify with the SIGMA= S_{B}option,
or you can request that be estimated
with the SIGMA = EST S_{B}option.
You can
specify with the DELTA= S_{B}option,
and you can
specify with the GAMMA= S_{B}option.
Note that the S_{B}options are given in
parentheses after the SB option.
proc capability; histogram length / sb; histogram length / sb( theta=est sigma=est ); histogram length / sb( theta=0.5 sigma=8.4 delta=0.8 gamma=0.6 ); run;The first HISTOGRAM statement fits an S_{B} distribution with default values of and and with percentilebased estimates for and .The second HISTOGRAM statement estimates all four parameters with the method of percentiles. The third HISTOGRAM statement displays an S_{B} curve with specified values for all four parameters.
Distribution Keyword  SIGMA= Specifies  Default Value  Alias 
BETA  scale parameter  1  SCALE= 
EXPONENTIAL  scale parameter  maximum likelihood estimate  SCALE= 
GAMMA  scale parameter  maximum likelihood estimate  SCALE= 
LOGNORMAL  shape parameter  maximum likelihood estimate  SHAPE= 
NORMAL  scale parameter  standard deviation  
SB  scale parameter  1  SCALE= 
SU  scale parameter  percentilebased estimate  
WEIBULL  scale parameter  maximum likelihood estimate  SCALE= 
whereYou can specify the parameters with the THETA=, SIGMA=, DELTA=, and GAMMA= S_{U}options, which are enclosed in parentheses after the SU option. If you do not specify these parameters, they are estimated.
location parameter scale parameter shape parameter shape parameter h = width of histogram interval
proc capability; histogram length / su; histogram length / su( theta=0.5 sigma=8.4 delta=0.8 gamma=0.6 ); run;The first HISTOGRAM statement estimates all four parameters with the method of percentiles. The second HISTOGRAM statement displays an S_{U} curve with specified values for all four parameters.
proc capability; histogram length / normal(w=3); run;The default is 1.
where threshold parameter scale parameter c = shape parameter (c >0) h = width of histogram intervalThe parameter must be less than the minimum data value. You can specify with the THETA= Weibulloption. The default value for is zero. If you specify THETA=EST, a maximum likelihood estimate is computed for .You can specify and c with the SIGMA= and C= Weibulloptions. By default, maximum likelihood estimates are computed for c and . For example, the following statements fit a Weibull distribution with and with maximum likelihood estimates for and c:
proc capability; histogram length / weibull(theta=15); run;
Chapter Contents 
Previous 
Next 
Top 
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.