Hello, I am trying to print a crosttabulation of mean,sd,n for a
continuous variable crossclassified by anoother/s grouping variables. I
came up with:
xtab2 <- function(x,g1,g2) {
funy <- function(z)
list(mean(z,na.rm=T),sd(z,na.rm=T),length(z))
aa <- by(x,list(g1,g2),funy)
bb <- matrix(unlist(aa),nrow=3
,dimnames=list(c("mean","sd","n"),
rep(levels(as.factor(g2)),
rep(length(levels(as.factor(g1))),
length(levels(as.factor(g2)))) ) ))
}
but as you can see the labels of the columns correspond only to the
second factor, and if I try to generalize it to 3 grouping variables the
thing does not work.
Any suggestions please on how to write the dimnames paragraph
appropriately?
Thanks
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On Thu, 23 May 2002 13:56:52 -0400 "R. Heberto Ghezzo" <heberto.ghezzo at mcgill.ca> wrote:> Hello, I am trying to print a crosttabulation of mean,sd,n for a > continuous variable crossclassified by anoother/s grouping variables. I > came up with: > xtab2 <- function(x,g1,g2) { > funy <- function(z) > list(mean(z,na.rm=T),sd(z,na.rm=T),length(z)) > aa <- by(x,list(g1,g2),funy) > bb <- matrix(unlist(aa),nrow=3 > ,dimnames=list(c("mean","sd","n"), > rep(levels(as.factor(g2)), > rep(length(levels(as.factor(g1))), > length(levels(as.factor(g2)))) ) )) > } > but as you can see the labels of the columns correspond only to the > second factor, and if I try to generalize it to 3 grouping variables the > thing does not work. > Any suggestions please on how to write the dimnames paragraph > appropriately? > Thanks >There are many ways to do this. One is to use functions in the Hmisc library: s <- summarize(x, llist(g1,g2,g3,g4), smean.sd) # smean.sd is in Hmisc: mean,sd To make a nice table (but only up to 2 cross-classification variables) do: summary(x ~ g1+g2, method='cross', fun=smean.sd) The latter will include the Ns for each cell. Frank Harrell> > -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- > 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 > _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._-- Frank E Harrell Jr Prof. of Biostatistics & Statistics Div. of Biostatistics & Epidem. Dept. of Health Evaluation Sciences U. Virginia School of Medicine http://hesweb1.med.virginia.edu/biostat -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Heberto, You write:>Hello, I am trying to print a crosttabulation of mean,sd,n for a >continuous variable crossclassified by anoother/s grouping variables. I >came up with: >xtab2 <- function(x,g1,g2) { > funy <- function(z) > list(mean(z,na.rm=T),sd(z,na.rm=T),length(z)) > aa <- by(x,list(g1,g2),funy) > bb <- matrix(unlist(aa),nrow=3 > ,dimnames=list(c("mean","sd","n"), > rep(levels(as.factor(g2)), > rep(length(levels(as.factor(g1))), > length(levels(as.factor(g2)))) ) )) >} >but as you can see the labels of the columns correspond only to the >second factor, and if I try to generalize it to 3 grouping variables the >thing does not work. >Any suggestions please on how to write the dimnames paragraph >appropriately?No ... but here is some code that, I think does what you want ... I think I got it from a previous post to R-help and tidied it up for my own use: means <- function(x, i, j=1, k=1) { FUN <- function(x) { c(mean(x, na.rm = TRUE), sd(x, na.rm = TRUE), length(x)) } if ((length(unique(j)) > 1) && (length(unique(k)) > 1)) { t <- tapply(x, list(i, j, k), FUN) a <- array(c(t ,recursive = TRUE), c(3, length(unique(i)), length(unique(j)), length(unique(k)))) dimnames(a) <- list(c("Mean", "SD", "N"), levels(as.factor(i)), levels(as.factor(j)), levels(as.factor(k))) } if (length(unique(j)) > 1 && length(unique(k)) == 1) { t <- tapply(x, list(i, j), FUN) a <- array(c(t, recursive = TRUE), c(3, length(unique(i)), length(unique(j)))) dimnames(a) <- list(c("Mean", "SD", "N"), levels(as.factor(i)), levels(as.factor(j))) } if (length(unique(j)) == 1) { t <- tapply(x, i, FUN) a <- array(c(t, recursive = TRUE), c(3, length(unique(i)))) dimnames(a) <- list(c("Mean", "SD", "N"), levels(as.factor(i))) } a <- formatC(a, digits = 3, width = 10, format = "f") print(a, quote = FALSE) } data(mtcars) means(mtcars$mpg, mtcars$gear, mtcars$carb) , , 1 3 4 5 Mean 20.333 29.100 17.150 SD 1.935 5.062 2.092 N 3.000 4.000 4.000 , , 2 3 4 5 Mean 24.750 28.200 16.300 SD 3.961 3.111 1.054 N 4.000 2.000 3.000 , , 3 3 4 5 Mean 12.620 19.750 15.800 SD 2.090 1.552 NA N 5.000 4.000 1.000 , , 4 3 4 5 Mean 19.700 15.000 20.333 SD NA NA 1.935 N 1.000 1.000 3.000 , , 6 3 4 5 Mean 29.100 17.150 24.750 SD 5.062 2.092 3.961 N 4.000 4.000 4.000 , , 8 3 4 5 Mean 28.200 16.300 12.620 SD 3.111 1.054 2.090 N 2.000 3.000 5.000 You should be able to get the dimnames() argument from that. Mark -- Mark Myatt -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._