aajit75
2011-Nov-29 12:50 UTC
[R] Any function\method to use automatically Final Model after bootstrapping using boot.stepAIC()
Hi List, Being new to R, I am trying to apply boot.stepAIC() for Model selection by bootstrapping the stepAIC() procedure. I had gone through the discussion in various thread on the variable selection methods. Understood the pros and cons of various method, also going through the regression modelling strategies in rms. I want to read Final model or Formula or list of variables automatically after boot.stepAIC(). n <- 200 x1 <- runif(n, -3, 3) x2 <- runif(n, -3, 3) x3 <- runif(n, -3, 3) x4 <- runif(n, -3, 3) x5 <- factor(sample(letters[1:2], n, rep = TRUE)) eta <- 0.1 + 1.6 * x1 - 2.5 * as.numeric(as.character(x5) == levels(x5)[1]) y1 <- rbinom(n, 1, plogis(eta)) data <- data.frame(y1,x1, x2, x3, x4, x5) glmFit1 <- glm(y1 ~ x1 + x2 + x3 + x4 + x5, family = binomial, data = data) bglmfit <- boot.stepAIC(glmFit1, data, B = 50) bglmfit In the summary of Bootstrapping the 'stepAIC()' procedure, Following information is listed: Initial Model: y1 ~ x1 + x2 + x3 + x4 + x5 Final Model: y1 ~ x1 + x5 Is there any function or method for using Final Model by Bootstrapping the 'stepAIC()' procedure, like OrigstepAIC model as shown below. n <- 200 x1 <- runif(n, -3, 3) x5 <- factor(sample(letters[1:2], n, rep = TRUE)) eta <- 0.1 + 1.6 * x1 - 2.5 * as.numeric(as.character(x5) == levels(x5)[1]) data1 <- data.frame(x1, x5) data1$probscore <- predict(bglmfit$OrigStepAIC , data1) Is there any way to read the variables or formula in the Final Model. Thanks in advance! Regards, ~Ajit -- View this message in context: http://r.789695.n4.nabble.com/Any-function-method-to-use-automatically-Final-Model-after-bootstrapping-using-boot-stepAIC-tp4119050p4119050.html Sent from the R help mailing list archive at Nabble.com.