 Hi:
 Using nls how can I increase the numbers of iterations to go beyond 50.
 I just want to be able to predict for the last two weeks of the year.
 This is what I have:

 weight_random <- runif(50,1,24)
 weight <- sort(weight_random);weight
weightData <- data.frame(weight,week=1:50)
                         weightData
plot(weight ~ week, weightData)
M_model <- nls(weight ~ alpha + beta*exp(gamma*week), weightData,
              start = c(alpha = 0.0, beta = 1, gamma = 0.2), trace = TRUE)
 
### I get the error below:
Error in nls(weight ~ alpha + beta * exp(gamma * week), weightData, start = c(alpha = 0,  : 
  number of iterations exceeded maximum of 50


M_model
### predict for another 2 weeks
newD <- data.frame(week = 1:52);newD
newD$pred_wt <- predict(M_model, newD)
newD
plot(pred_wt ~ week, newD, pch = 4, col = "red", ylab = "Weight", xlab = "Week")
with(weightData, points(week, weight,col='blue'))


Felipe D. Carrillo
Supervisory Fishery Biologist
Department of the Interior
US Fish & Wildlife Service
California, USA
http://www.fws.gov/redbluff/rbdd_jsmp.aspx

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