Complex Piecewise Regression Analysis

FIGURE 9.12 Data plot of logio populations recovered. Example 9.2. 

Example 9.3 In a study for absorption and elimination of oral drug 2121-BO , the following blood levels of the active Tinapticin-3 were determined by means of HPLC analysis (Table 9.26). 

This approach to the pivotal points needs to be checked, ideally not just for this curve, but for application in other studies. That is, it is wise to keep the piece components as few as possible, because the idea is to create a model that can be used across studies, not just for one particular study. Technically, one could fit each value as a piecewise computation until one ran out of degrees of freedom, but this is not useful. 

To build the model, we must create a h, and an jc, for each pivot point, in addition to the first or original segment. The proposed model, then, is 

The results of regression using this model are presented in Table 9.27. The model seems adequate, but the performance should be compared among other similar studies, if available. The actual input y, x, x—5, and x—9 data, as well as y and e are presented in Table 9.28. 

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