Yimeng Lu
2005-Jul-17 23:38 UTC
[R] how to solve the step halving factor problems in gnls and nls
Hi R-users, Could you give me some advice in solving the problem of such error message from gnls and nls? ## begin error message "Problem in gnls(y1 ~ glogit4(b, c, m, t, x), data.frame(x..: Step halving factor reduced below minimum in NLS step " ##and "Problem in nls(y ~ 1/(1 + exp((xmid - x)/scal)), data = x..: step factor reduced below minimum "? Thank you in advance. Hanna [[alternative HTML version deleted]]
Dieter Menne
2005-Jul-19 06:42 UTC
[R] how to solve the step halving factor problems in gnls and nls
Yimeng Lu <yl2058 <at> columbia.edu> writes:> Could you give me some advice in > solving the problem of such error message from gnls and nls? > ## begin error message > > "Problem in gnls(y1 ~ glogit4(b, c, m, t, x), data.frame(x..: Step halving > factor reduced below minimum in NLS step " >Try to set nlsTol in the optional control parameter (gnlsControl) to a larger value, e.g. 0.1 instead of default 0.001, but be sure to check your results make sense. If this should help, you can try intermediate values. Dieter Menne