Dear colleagues!
Is it possible to make predictions in R?
there is an exponential relationship detween y and x
x<-c(0.001,0.003,0.01,0.16,0.3,0.7,0.9)
y<-c(38.8,41.5,44.2,27,26.9,6.9,3)
f<-function(x,a,b){a*exp(b*x)}
fm<-nls(y~f(x,a,b), start=c(a=1,b=1))
How one can predict x when y=10 and is it possible to calculate standard
error of x?
The task is equal to function ED in drc package, but it use logistic
regression only.
Best regards,
Elena.
--
daryd at rambler.ru.
Dear colleagues!
Is it possible to make predictions in R?
there is an exponential relationship detween y and x
x<-c(0.001,0.003,0.01,0.16,0.3,0.7,0.9)
y<-c(38.8,41.5,44.2,27,26.9,6.9,3)
f<-function(x,a,b){a*exp(b*x)}
fm<-nls(y~f(x,a,b), start=c(a=1,b=1))
How one can predict x when y=10 and is it possible to calculate standard
error of x?
The task is equal to function ED in drc package, but it use logistic
regression only.
Best regards,
Elena.
--
daryd at rambler.ru.
predict x for a given y(response)? If this is the case, you will have multiple x for a single y for this exponential model. In terms of logistic regression, If y =1, logit([P(Y=1)] = a + b*bx has infinite many x. The question seems not quite clear to me. -- View this message in context: http://r.789695.n4.nabble.com/forecasting-with-non-linear-models-tp2531125p2531186.html Sent from the R help mailing list archive at Nabble.com.