GPS-X Technical Reference

Optimizer 384
Confidence Limits Sub-Section
Printing of confidence limits (ON - OFF): Controls the calculation and printing of
confidence limits for the parameter estimates. When this option is ON the confidence
limits are reported to the Log window and if requested to the stats.txt file. When this
option is OFF (default), the confidence limits are not calculated or printed to the Log
window or the stats.txt file. Confidence limits are only reported when the maximum
likelihood or the sum of squares objective functions are used. This switch does not affect
the outcome of an optimization run.
Confidence level for confidence limits: The level of confidence used when calculating
the confidence limits. The default value of 0.95 corresponds to 95 percent confidence
limits.
Treat the different target variables as one target (ON - OFF): If there is more than
one target variable and the maximum likelihood objective function is used, this switch
controls whether the different targets are treated as the same target for the purposes of
calculating the degrees of freedom used in the Student’s t-statistic in the confidence
limits calculations. This feature is useful if you have a number of different target
variables that are actually the same variable measured in different experiments.
Significance of the Regression Sub-Section
Level of significance for significance of regression test: This is the level of
significance used in the significance of the regression test. An appropriate message is
printed by GPS-X depending on the calculated probability value and the level of
significance. If the probability is larger than the chosen significance level (default value
is 0.05) it provides evidence that the parameters are all zero and that the regression is not
significant for the corresponding target variable. If the probability value is smaller than
the significance level it indicates that the regression is significant for the corresponding
target variable and that the variation explained by the regression is greater than expected
by chance. This test is only reported when the maximum likelihood or the sum of squares
objective functions are used. It does not affect the outcome of an optimization run.
Lack of Fit Sub-Section
Lack of fit test (ON - OFF): Controls the printing of the lack of fit test. If this option is
set to ON and the detailed statistical report is set to ON, the lack of fit test is printed to
the Log window and if necessary the stats.txt file. This test determines whether the
variance of the residuals is acceptable compared to the user supplied estimate of the
measurement variance or the measurement variance calculated using replicate
measurements. This test is only reported when the maximum likelihood or the sum of
squares objective functions are used. It does not affect the outcome of an optimization
run.
GPS-X Technical Reference