search for: spottedseatrout2004

Displaying 1 result from an estimated 1 matches for "spottedseatrout2004".

2008 Feb 15
3
Error 'singular gradient' in nonlinear model fitting
w.age.female.2004 <- nls(WEIGHT ~ (alpha*TOTAL^beta)/454, start=list(alpha=1, beta=3), data=spottedseatrout2004.female.data) I am trying to fit above model to length-weight data of a fish species (spotted seatrout) by year (1999-2006). The convergence occurred for all the years except 2002 and 2004. In these two year, R shows the error called 'singular gradient' in the model. Could anyone please...