Examples of successful and unsuccessful sigmoidal curve fitting.

<p><b>A</b>. Successful sigmoidal curve fit where the data cover the estimated point of maximum growth (PMG). <b>B</b>. Successful sigmoidal curve fit even though data are not available for the estimated PMG. <b>C</b>. Unsuccessful sigmoidal curve fit due to the lack of informative data for fitting the curve. Line, fitted sigmoidal curve.