Hello,
I'm currently trying to fit an exponetial curve to a set of data that includes the equation label. I would also like to possibly include an R^2 value and p-value. I know that one way to do this is to use the stat_fit_tidy using a nls. Using the provided mtcars dataset
ggplot(mtcars, aes(x = disp, y = mpg, colour = factor(cyl))) +
geom_point() +
stat_smooth(method = "nls"
, formula = y ~ A * exp( B * x)
, method.args = list( start = c( A = 2, B = 0.2 ))
stat_fit_tidy(method = "nls",
method.args = list(formula = y~A*exp(B*x)),
size = 3,
label.x = "center",
label.y = "bottom",
parse = TRUE)
I'm struggling to get A and B to be correct values, I keep getting the error
"Warning message:
Computation failed in stat_smooth()
:
singular gradient "
I think this is because A or B isn't close enough to their actual values. However, even when I try this on other dataset and get A and B correct, I still can't figure out how to use stat_fit_tidy correctly. How would I do this correctly? Is there a easier way of doing this. It's sort of frustrating that this is something that's very simple to do in Excel but complicated in R