Frede Thank you very much for the help. Indeed, I am trying to do exactly what you wrote the code for. I may have caused some confusion though as a result of a typographic error in my equation: the result of the equation should EQUAL to the value of 1. I see you have inputted the equation into the function as 1 - (minus) D1/... would you be kind to please provide insights on how that may change the the function is written? By using the equation that way the value of E should be between 1.5 and 6, based on data I have available in a plot, if that helps.
Greatly appreciate the help Thanks Andras [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.