similar to: for loop over dataframe without indices

Dear list, this works fine: x <- split(iris, iris$Species) x1 <- lapply(x, function(L) transform(L, g = L[,1:4] * 3)) but I would like to multiply each Species with another factor: setosa by 2, versicolor by 3 and virginica by 4. I've tried mapply but without success. Any thoughts? Thanks for any idea! Patrick

Dear R list, I'm trying to calculate Mahalanobis distances for 'Species' of 'iris' data as obtained below: Squared Distance to Species From Species: Setosa Versicolor Virginica Setosa 0 89.86419 179.38471 Versicolor 89.86419 0 17.20107 Virginica 179.38471 17.20107 0 These distances were obtained with proc 'CANDISC'

Dear RRRRRrrrrrrrrlist! I?ve got two lists which contain sets of DNA-sequences. They look something like this: List of 33 $ Cunonia_atrorubens : chr [1:247] "t" "t" "n" "t" ... $ Cunonia_balansae : chr [1:254] "t" "c" "c" "c" ... $ Cunonia_capensis : chr

I tried it using file and it seems to work for saving: > data(iris) > con <- file("clipboard","w") > save(iris,ascii=T,file=con) > close(con) > readLines("clipboard") ... lengthy output follows which seems correct ... but not for loading: > con <- file("clipboard","r") > load(con) Error in load(con) : loading from

Hi folk, I tried this and it works just perfectly tapply(iris[,1],iris[5],mean) but, how to obtain a single table from multiple variables? In tapply x is an atomic object so this code doesn't work tapply(iris[,1:4],iris[5],mean) Thanx and great summer holidays Gianandrea -- View this message in context: http://www.nabble.com/multiple-tapply-tp18868063p18868063.html Sent from the R help

Dear R-help forum members, Suppose I have a data-frame having two variables and single data for each of them, as described below. variable_1           variable_2         10                          20 I have written a function, say, 'fun' which uses input 10 and 20 and gives me desired result. fun = function(X, Y)          {          X + Y              #( I am just giving an example of

Dear R list, I'm trying to calculate Mahalanobis distances for 'Species' of 'iris' data as obtained below: Squared Distance to Species From Species: Setosa Versicolor Virginica Setosa 0 89.86419 179.38471 Versicolor 89.86419 0 17.20107 Virginica 179.38471 17.20107 0 This distances above were obtained with proc

I've just tried to merge 2 data sets thinking they would only keep the common columns, but noticed the column count was not adding up. I've then replicated a simple example and got the same thing happening. q1. why doesn't 'b' have a column name? q2. when I merge, why does the new column 'y' have all values as 5.1? Thanks in advance, Mr. confused > a <-

I have a dataset and I wish to use two different models to predict. Both models are SVM. The reason for two different models is based on the sex of the observation. I wish to be able to make predictions and have the results be in the same order as my original dataset. To illustrate I will use iris: # Take Iris and create a dataframe of just two Species, setosa and versicolor, shuffle them

Hi, Since I've had no replies on my previous post about my problem I am posting it again in the hope someone notice it. The problem is that the randomForest function doesn't take datasets which has instances only containing a subset of all the classes. So the dataset with instances that either belong to class "a" or "b" from the levels "a", "b" and

I use by() to generate a summary statistics like so: Lbys <- by(dat[Nidx], dat$LipTest, summary) where Nidx is an index vector with names picking out the columns in the data frame dat. This returns a list of character arrays (see below for str() output) where the columns are named correctly but the rownames are empty strings and the values are strings prepended with the summary

Hi there: I have a question about generating mean value of a data.frame. Take iris data for example, if I have a data.frame looking like the following: --------------------- 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

Hi all, I have to recode some values in a dataset. for example changing all zeros to "." or 999 would be also ok. does anybody know how to do this? thanks in advance. lars -- View this message in context: http://www.nabble.com/-R--Replacing-values-tf2841687.html#a7934402 Sent from the R help mailing list archive at Nabble.com.

Dear all What is the easy way to drop a variable by using its name (and not its number)? Example: > data(iris) > head(iris) 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 4 4.6 3.1

Is this a bug? I thought that "clipboard" could always be substituted for a filename when dealing with ASCII files. > data(iris) > save(iris,ascii=TRUE,file="clipboard") Error in file(file, "wb") : `mode' for the clipboard must be `r' or `w' Also this (where gclip is a utility found at unxutils.sourceforge.net that copies its standard input to the

Dear R-help, First I apologize if my question is quite simple. I need add some of data in the first place my dataset, how can I do that. I have tried with rbind, but I did not succes. 0.1 3.6 0.4 0.9 rose 4.1 4.0 1.2 1.2 rose 4.4 3.2 1.9 0.5 rose 4.6 1.1 1.1 0.2 rose For example,

Hi all, Using RConsole, it's easy to get data from the database that you can use in an R Command. Like this: (Reference case) irisQuery <- dbGetQuery(conn, "select * from iris") boxM(irisQuery [,-5], irisQuery[,5]) ---- (Actual case this posting is about) Yet, if I'm getting that same (sample IRIS) data, say, in a web service possibly POSTED from a SQL command, that same

That's amazing! Thank you!!! One follow up question, if that's OK? If, instead of using hard-coded CSV, I read the CSV into a variable first, then it fails again with a parse error. Code below. So, if I read the CSV into a variable, do I need an additional wrapper method? Seems like it should still work. Thanks in advance for your reply. -M String inputIris =

Just out of curiosity, I took the default "iris" example in the RF helpfile... but seeing the admonition against using the formula interface for large data sets, I wanted to play around a bit to see how the various options affected the output. Found something interesting I couldn't find documentation for... Just like the example... > set.seed(12) # to be sure I have

Dear all, I'd like to get a percentage variable based on a group, but without creating a new data frame. For example: data(iris) iris$percent <-unlist(tapply(iris$Sepal.Length,iris$Species,function(x) x/sum(x, na.rm=TRUE))) This does not work, I should have only three standard values, respectively for setosa, versicolor, and virginica. How can I do this? MANY THANKS, Karine