Results
What is the approximation error of the result?
The approximation error indicators (predict the metamodel accuracy of the results) can be either visualized in the LS-OPT Viewer or found in the lsopt_output file, e.g. for the response HIC you may find:
LS-OPT Viewer
Start the LS-OPT Viewer by selecting the View tab and
→ The coefficient of determination (R2) is high (=0.922), but the RMS Error may need further improvement, e.g. more iterations or selection of a more suitable metamodel (e.g. Feedforward Neural Network or Radial Basis Function Network). Nevertheless for a raw estimate the result may be considered as acceptable. | |
lsopt_output File
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With the same procedure you may find the RMS Error and R2 of the other responses:
| Mean Response Value | RMS Error | R2 |
MASS | 0.7742 | 0 | 1 |
Disp1 | -159.3846 | 2.0286 (1.27%) | 0.4790 |
Disp2 | -694.5753 | 5.5459 (0.80%) | 0.9896 |
HIC | 275.72 | 76.5620 (27.77%) | 0.9224 |
Which variable appears to be the most important?
The significance of a variable for a response can be illustrated with ANOVA (analysis of variance) or GSA/Sobol (global sensitivity ananlysis), e.g for the response HIC you may find:
LS-OPT Viewer
ANOVA
→ For the response HIC the variable thood is more important, while the variable tbumper is rather insignificant.
GSA/Sobol
→ We come to the same conclusion by using GSA. The influence of thood on HIC is 84.9%, larger than that of tbumper (15.1%). | |
lsopt_output File
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Study the change in each of the variables/responses and the accuracy of the predicted compared to the computed result.
The accuracy of the starting point and the approximate optimum points after the first iteration can be illustrated, e.g. for the response HIC you may find:
LS-OPT Viewer
→ You can find out the appropriate values for the predicted (black) and the computed (red points) results. More iterations may lead to a better predictive capability.
| (Note the range of the values when assessing the accuracy) |
lsopt_output File
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With the same procedure you may find the other values of the variables and the responses:
Start | First Iteration | |||||||||||||||
Predicted | Computed | Predicted | Computed | |||||||||||||
thood | 1 | 1.548 | ||||||||||||||
tbumper | 3 | 5 | ||||||||||||||
MASS | 0.4103 | 0.4103 | 0.6569 | 0.6569 | ||||||||||||
Intrusion | 577.3 | 575.7 | 550 | 550.5 | ||||||||||||
HIC | 74.57 | 68.02 | 38.63 | 126.5 | ||||||||||||
Max. Constr. Violation | 27.27 | 25.68 | 1.162e-4 | 0.4658 |