apply problem
On Sat, 16 Mar 2002 ggrothendieck at yifan.net wrote:
data(iris)
# iris3 is first 3 rows of iris
iris3 <- iris[1:3,]
Not a good choice of name: iris3 is another R dataset. Your iris3 is a data frame.
# z compares row 1 to each row of iris3 and is correctly computed
z <- c(F,F,F) for(i in seq(z)) z[i] <- identical(iris3[1,],iris3[i,]) z
[1] TRUE FALSE FALSE # this should do the same but is incorrect
apply(iris3,1,function(x)identical(x,iris3[1,]))
1 2 3 FALSE FALSE FALSE What's wrong here?
You are not using array as documented. ?apply says
Arguments:
X: the array to be used.
iris3 is not an array, so it it coerced to one via as.matrix
as.matrix(iris3)
Sepal.Length Sepal.Width Petal.Length Petal.Width Species 1 "5.1" "3.5" "1.4" "0.2" "setosa" 2 "4.9" "3.0" "1.4" "0.2" "setosa" 3 "4.7" "3.2" "1.3" "0.2" "setosa" and that's not the same object as your iris3
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._