[R] Pseudodataset text file

Dan Janes djanes at oeb.harvard.edu
Mon Jun 13 20:33:26 CEST 2005


Hi All,

Two weeks ago, I received instructions from the R list about creating 
pseudodatasets by bootstrapping an existing dataset 1000 times.  I received 
code that bootstrapped my dataset and ran an ANOVA on each pseudodataset, 
producing a histogram of F-values.  Here is the code I received that 
produces this F-histogram.

X <- data.frame(b=rnorm(2162),c =factor(rep(1:47,each=46)))

## linear fit with true values
lm0 <- lm(b~c,data=X)
Fvals <- numeric(1000)
for (i in 1:1000) {
    X.boot <- X[sample(1:nrow(X),replace=TRUE),]
    Fvals[i] <- anova(lm(b~c,data=X.boot))$"F value"[1]
}
hist(Fvals)

I am grateful for the assistance but the code does not provide what I 
need.  I need the 1000 pseudodatasets produced by the bootstrap in order to 
work with them in a different context.  Can you someone offer a suggestion 
on how to produce the bootstrapped datasets as a text file?

Thank you.

-Dan



************************************************
Dan Janes, Ph.D.
Harvard University/OEB
26 Oxford St.
Cambridge, MA 02138
Office: 617-496-2375
Fax: 617-495-5667
Email: djanes at oeb.harvard.edu




More information about the R-help mailing list