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Dear All, A couple of questions about the nls package. 1. I'm trying to run a nonlinear least squares regression but the routine gives me the following error message: step factor 0.000488281 reduced below `minFactor' of 0.000976563 even though I previously wrote the following command: nls.control(minFactor = 1/4096), which should set the minFactor to a lower level than the default

Dear All, I am trying to fit to the data a nonlinear function, say z(tau;b) where tau is the independent variable and b is 3x1 vector of parameters. Following previous suggestions from the list, I am trying to find some "optimal" starting values for the three parameters by using the command 'optim' and then feed these values to nls for estimation. Does anybody know hot to