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SPSS® 12.0 Command Syntax Reference

SPSS® 12.0 Command Syntax Reference

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1052 NLR<br />

• Some new parameters may be specified for the model on the MODEL PROGRAM<br />

command while others are read from the file specified on the FILE subcommand.<br />

• You do not have to name the parameters on MODEL PROGRAM in the order in which they<br />

occur in the parameter data file. In addition, you can name a partial list of the variables<br />

contained in the file.<br />

• If the starting value for a parameter is specified on MODEL PROGRAM, the specification<br />

overrides the value read from the parameter data file.<br />

• If split-file processing is in effect, the starting values for the first subfile are taken from<br />

the first case of the parameter data file. Subfiles are matched with cases in order until the<br />

starting value file runs out of cases. All subsequent subfiles use the starting values for the<br />

last case.<br />

• To read starting values from a parameter data file and then replace those values with the<br />

final results from [C]NLR, specify the same file on the FILE and OUTFILE subcommands.<br />

The input file is read completely before anything is written in the output file.<br />

Example<br />

MODEL PROGRAM A B C=1 D=3.<br />

COMPUTE PRED=A*SPEED**B + C*SPEED**D.<br />

NLR STOP /FILE=PARAM /OUTFILE=PARAM.<br />

• MODEL PROGRAM names four of the parameters used to calculate PRED, but assigns<br />

values to only C and D. The values of A and B are read from the existing data file PARAM.<br />

• After NLR computes the final estimates of the four parameters, OUTFILE writes over the<br />

old input file. If, in addition to these new final estimates, the former starting values of A<br />

and B are still desired, specify a different file on the OUTFILE subcommand.<br />

PRED Subcommand<br />

PRED identifies the variable holding the predicted values.<br />

• The only specification is a variable name, which must be identical to the variable name<br />

used to calculate predicted values in the model program.<br />

• If the model program names the variable PRED, the PRED subcommand can be omitted.<br />

Otherwise, the PRED subcommand is required.<br />

• The variable for predicted values is not saved in the working data file unless the SAVE<br />

subcommand is used.<br />

Example<br />

MODEL PROGRAM A=.5 B=1.6.<br />

COMPUTE PSTOP=A*SPEED**B.<br />

NLR STOP /PRED=PSTOP.<br />

• COMPUTE in the model program creates a variable named PSTOP to temporarily store the<br />

predicted values for the dependent variable STOP.<br />

• PRED identifies PSTOP as the variable used to define the model for the NLR procedure.

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