Re: [R] nls() and loop

2017-10-21 Thread Martin Maechler
Dear Vangi, > Evangelina Viotto > on Fri, 20 Oct 2017 11:37:12 -0300 writes: > Hello I´m need fitt growth curve with data length-age. I want to evaluate > which is the function that best predicts my data, to do so I compare the > Akaikes of different models. I'm now need

Re: [R] nls() and loop

2017-10-20 Thread J C Nash
Yes, some form of try() is often needed with nls() to avoid scripts stopping. You might also find nlxb() from package nlsr more reliable in finding solutions. It uses analytic derivatives if available if the model is given as an expression, and a Marquardt stabilized solver. But do expect it to

Re: [R] nls() and loop

2017-10-20 Thread Jeff Newmiller
?tryCatch -- Sent from my phone. Please excuse my brevity. On October 20, 2017 7:37:12 AM PDT, Evangelina Viotto wrote: >Hello I´m need fitt growth curve with data length-age. I want to >evaluate >which is the function that best predicts my data, to do so I compare >the >Akaikes of different mo

[R] nls() and loop

2017-10-20 Thread Evangelina Viotto
Hello I´m need fitt growth curve with data length-age. I want to evaluate which is the function that best predicts my data, to do so I compare the Akaikes of different models. I'm now need to evaluate if changing the initial values changes the parameters and which do not allow to estimate the model