##########
##
# Reading the data into R:

my.datafile <- tempfile()
cat(file=my.datafile, "  
15 1 340 1 
15 2 355 1 
15 3 370 1 
15 4 345 1 
15 5 300 1 
15 6 310 1 
25 1 280 1 
25 2 255 1 
25 3 275 1 
25 4 270 1 
25 5 250 1 
25 6 190 1 
35 1 335 1 
35 2 315 1 
35 3 320 1 
35 4 315 1 
35 5 225 1 
35 6 285 1 
15 1 318 15 
15 2 316 15 
15 3 309 15 
15 4 324 15 
15 5 310 15 
15 6 279 15 
25 1 349 15 
25 2 336 15 
25 3 342 15 
25 4 304 15 
25 5 306 15 
25 6 379 15 
35 1 309 15 
35 2 309 15 
35 3 313 15 
35 4 304 15 
35 5 292 15 
35 6 270 15 
", sep=" ")

options(scipen=999) # suppressing scientific notation

cakedata <- read.table(my.datafile, header=FALSE, col.names=c("temp", "obs", "volume", "day")) 

attach(cakedata)

temp <- factor(temp)

day <- factor(day)

#
####