I recently used drc to fit four parameter log-logistic models for some drug screen data. I noticed that in some cases, drc produces fits with very large values for the e parameter.
Of those 3,589 values, many are "close" (but still well outside of) the expected range, while a fair number of many orders of magnitude larger than expected:
Greetings,
I recently used drc to fit four parameter log-logistic models for some drug screen data. I noticed that in some cases, drc produces fits with very large values for the
e
parameter.For example:
That is the most extreme example, but there appears to be a continuous distribution of larger-than-expected values.
Out of ~89,000 curves fit, 3,589 had values outside of the range of values (>~115) produced by a different tool (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3040458/).
Of those 3,589 values, many are "close" (but still well outside of) the expected range, while a fair number of many orders of magnitude larger than expected:
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