ESTIMATE Statement
 ESTIMATE item [ , item ... ] [ ,/ options ] ;
The ESTIMATE statement computes estimates of functions
of the parameters.
The ESTIMATE statement refers to the parameters estimated
by the associated FIT statement
(that is, to either the preceding FIT statement or,
in the absence of a preceding FIT statement, to the
following FIT statement).
You can use any number of ESTIMATE statements.
If you specify options on the ESTIMATE statement,
a comma is required before the "/" character separating
the test expressions from the options,
since the "/" character can also be used within test expressions to
indicate division.
Each item is written as an optional name followed by an expression
 [ "name" ] expression
where "name" is a string used to identify the estimate
in the printed output and in the OUTEST= data set.
Expressions can be composed of parameter names,
arithmetic operators, functions, and constants.
Comparison operators (such as "=" or "<") and logical operators (such
as "&")
cannot be used in ESTIMATE statement expressions.
Parameters named in ESTIMATE expressions must be among the parameters
estimated by the associated FIT statement.
You can use the following options in the ESTIMATE statement:
 OUTEST=

specifies the name of the data set in which the estimate of
the functions of the parameters are to
be written. The format for this data set is identical to
the OUTEST= data set for the FIT statement.
If you specify a name in the ESTIMATE statement,
that name is used as the parameter name for the estimate
in the OUTEST= data set.
If no name is provided and the expression is just a symbol,
the symbol name is used; otherwise, the string "_Estimate #" is used,
where "#" is the variable number in the OUTEST= data set.
 OUTCOV

writes the covariance matrix of the functions of the parameters to
the OUTEST= data set in addition to the parameter estimates.
 COVB

prints the covariance matrix of the functions of the parameters.
 CORRB

prints the correlation matrix of the functions of the parameters.
The following is an example of the use of the ESTIMATE statement
in a segmented model:
data a;
input y x @@;
datalines;
.46 1 .47 2 .57 3 .61 4 .62 5 .68 6 .69 7
.78 8 .70 9 .74 10 .77 11 .78 12 .74 13 .80 13
.80 15 .78 16
;
title 'Segmented Model  Quadratic with Plateau';
proc model data=a;
x0 = .5 * b / c;
if x < x0 then y = a + b*x + c*x*x;
else y = a + b*x0 + c*x0*x0;
fit y start=( a .45 b .5 c .0025 );
estimate 'Join point' x0 ,
'plateau' a + b*x0 + c*x0**2 ;
run;
Segmented Model  Quadratic with Plateau 
Nonlinear OLS Estimates 
Term 
Estimate 
Approx Std Err 
t Value 
Approx Pr > t 
Label 
Join point 
12.7504 
1.2785 
9.97 
<.0001 
x0 
plateau 
0.777516 
0.0123 
63.10 
<.0001 
a + b*x0 + c*x0**2 

Figure 14.14: ESTIMATE Statement Output
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.