Hello there,

I am trying to use R function NLS to analyze my data and one of the examples
in the documentation is -

## the nls() internal cheap guess for starting values can be sufficient:

x <- -(1:100)/10
y <- 100 + 10 * exp(x / 2) + rnorm(x)/10
nlmod <- nls(y ~  Const + A * exp(B * x), trace=TRUE)

plot(x,y, main = "nls(*), data, true function and fit, n=100")
curve(100 + 10 * exp(x / 2), col=4, add = TRUE)
lines(x, predict(nlmod), col=2)

However, when I try to execute this - I get the following error-

Error in nls(y ~ Const + A * exp(B * x), trace = TRUE) :
  step factor 0.000488281 reduced below 'minFactor' of 0.000976562
In addition: Warning message:
In nls(y ~ Const + A * exp(B * x), trace = TRUE) :
  No starting values specified for some parameters

Can someone propose how I can fix this error? Thanks.

Diviya

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