Figure 2.
Simulations of analysis using Equation (6). Responses in two systems were simulated with Equation (A22) for four ligands (A–D). The seed (true mean) and simulated parameters are summarized in Table 2, and the results of fitting Equation (6) are summarized in Table 4. Points are the mean ± SEM of six simulated data sets, and the curves show the mean of the fitted curves. The values of the system‐related parameters (bkgd, E max, χ 1, χ 2 and n) were shared for all ligands during fitting. For ‘response 1’, the SD of the normal distribution defining the between‐occasion variability was set to 15% of the mean value of the normally distributed parameters. For the log‐normally distributed parameters except n, the SD of the log of the parameter was set to 0.15. The SD of the within‐occasion variability was set to 15% of the simulated mean value at each agonist concentration (giving proportional rather than constant errors). For ‘response 2’, the SD of the between‐occasion variability was set to 20% of the mean value of the normally distributed parameters. For the log‐normally distributed parameters except n, the SD of the log of the parameter was set to 0.20. The SD of the within‐occasion variability was set to 20% of the simulated mean value at each agonist concentration. In both cases, the SD of n was set to one‐third of that of the other parameters.