Displaying 20 results from an estimated 2000 matches similar to: "more on apply on data frame"
2010 Jun 09
4
question about "mean"
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
2008 Aug 07
6
multiple tapply
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
--
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Sent from the R help
2001 Feb 19
1
means by column after split
Colleagues
----------------------------------
System info:
R version rw1020 on NT
ESS using emacs ver. 20.4
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I need to get the means for each column of a dataframe in the list
created by splitting a data frame. At present, I am getting the mean of all
columns in aggregate.
The structure of the unsplit data is:
> shuttle.tr1[1:10,]
juliandate
2012 Jun 11
1
saving sublist lda object with save.image()
Greetings R experts,
I'm having some difficulty recovering lda objects that I've saved within sublists using the save.image() function. I am running a script that exports a variety of different information as a list, included within that list is an lda object. I then take that list and create a list of that with all the different replications I've run. Unfortunately I've been
2010 Dec 15
3
Applying function to a TABLE and also "apply, tapply, sapply etc"
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
2008 Oct 01
2
an unsophisticated question about recoding in a data frame with control structure if {}
Hello all,
I apologize for a terribly simple question. I'm used to using Stata and am trying to `switch' over to R.
I would like to recode a vector in a data frame when the value of it meets the following condition: if (dataframe$factor=='3'){dataframe$thevector<-(an arithmetic mean). What I would like to result is the creation of a new variable within the data frame for
2012 Oct 10
2
Summary using by() returns character arrays in a list
I use by() to generate a summary statistics like so:
Lbys <- by(dat[Nidx], dat$LipTest, summary)
where Nidx is an index vector with names picking out the columns in the
data frame dat.
This returns a list of character arrays (see below for str() output) where
the columns are named correctly but the rownames are empty strings and the
values are strings prepended with the summary
2018 Mar 23
2
aggregate() naming -- bug or feature
In the examples below, the first loses the name attached by foo(), the second retains names attached by bar(). Is this an intentional difference? I?d prefer that the names be retained in both cases.
foo <- function(x) { c(mean = base::mean(x)) }
bar <- function(x) { c(mean = base::mean(x), sd = stats::sd(x))}
aggregate(iris$Sepal.Length, by = list(iris$Species), FUN = foo)
#>
2018 Mar 23
1
aggregate() naming -- bug or feature
On Fri, Mar 23, 2018 at 6:43 PM, Rui Barradas <ruipbarradas at sapo.pt> wrote:
> Hello,
>
> Not exactly an answer but here it goes.
> If you use the formula interface the names will be retained.
Also if you pass named arguments:
aggregate(iris["Sepal.Length"], by = iris["Species"], FUN = foo)
# Species Sepal.Length
# 1 setosa 5.006
# 2
2012 Aug 28
1
don't print object attributes
Dear all
Suppose the object below:
> require(Hmisc)
> require(plyr)
> x <- dlply(iris, .(Species), describe)
How can I print the object without displaying the attributes? I
inspected ?print and ?print.default with no luck.
> x
$setosa
x[, "Sepal.Length"]
n missing unique Mean .05 .10 .25 .50 .75
50 0 15 5.006 4.40 4.59
2005 Sep 16
6
How do I get the row indices?
Hi,
I was wondering if it's possible to get the row
numbers from a filtering. Here's an example:
# give me the rows with sepal.length == 6.2
iris[(iris[,1]==6.2),]
# output
Sepal.Length Sepal.Width Petal.Length Petal.Width
Species
69 6.2 2.2 4.5 1.5
versicolor
98 6.2 2.9 4.3 1.3
versicolor
127 6.2
2005 Sep 26
3
How to get the rowindices without using which?
Hi,
I was wondering if it is possible to get the
rowindices without using the function "which" because
I don't have a restriction criteria. Here's an example
of what I mean:
# take 10 randomly selected instances
iris[sample(1:nrow(iris), 10),]
# output
Sepal.Length Sepal.Width Petal.Length Petal.Width
Species
76 6.6 3.0 4.4 1.4
2018 Mar 06
0
couple of how-to-do it in R questions regarding corelations and mean and SD of likert items
Hi
For first question, maybe I am completely wrong but
cor(swiss[,-1], swiss[,1])
should give you what you want in one step.
Second question
Without an example it is hard to say but maybe aggregate is the way forward.
> aggregate(iris[,1:4], list(iris$Species), function (x) c(mean=mean(x), sd=sd(x)))
Group.1 Sepal.Length.mean Sepal.Length.sd Sepal.Width.mean Sepal.Width.sd
1
2017 Oct 28
2
Cannot Compute Box's M (Three Days Trying...)
Hey Duncan,
Hard to debug? That's an understatement. Eyes bleeding....
In any case, I tried all your suggestions. To get "integer" for the final column, I had to change the code to get integers instead of strings.
double[] d1 = ((REXPVector) ((RList) tableRead).get(0)).asDoubles();
double[] d2 = ((REXPVector) ((RList) tableRead).get(1)).asDoubles();
double[] d3 = ((REXPVector)
2013 Jan 16
4
Get a percent variable based on group
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$Species,function(x) x/sum(x, na.rm=TRUE)))
This does not work, I should have only three standard values, respectively for setosa, versicolor, and virginica. How can I do this?
MANY THANKS,
Karine
2017 Oct 28
2
Cannot Compute Box's M (Three Days Trying...)
Thanks Duncan. Awesome ideas!
I think we're getting closer!
I tried what you suggested and got a possibly better error...
.
.
.
rConnection.assign("boxMVariable", myDf);
String resultBV = "str(boxMVariable)"; // your suggestion.
RESULTING ERROR:
Error in format.default(nam.ob, width = max(ncn), justify = "left") : invalid 'width' argument
(No idea
2017 Oct 29
2
Cannot Compute Box's M (Three Days Trying...)
Thanks Duncan. I can't tell you how helpful all your terrific replies have been.
I think the biggest surprise is that nobody appears to be using Java and R together like I"m trying to do. I suppose it should be a surprise since there are no books on the subject and almost no technical documentation other than a few sites here and there.
-----
I originally had the "int" as the
2010 Sep 21
5
removed data is still there!
I'm confused, hope someone can point out what is not obvious to me.
I thought I was creating a new data frame by 'deleting' rows from an
existing dataframe - I've tried 2 methods.
But this new data frame seems to remember values from its parent - even
though there are no occurences.
Where does it get the values versicolor and virginica from and give then a
count of 0?
What
2012 Aug 01
3
Neuralnet Error
I require some help in debugging this code
library(neuralnet)
ir<-read.table(file="iris_data.txt",header=TRUE,row.names=NULL)
ir1 <- data.frame(ir[1:100,2:6])
ir2 <- data.frame(ifelse(ir1$Species=="setosa",1,ifelse(ir1$Species=="versicolor",0,"")))
colnames(ir2)<-("Output")
ir3 <- data.frame(rbind(ir1[1:4],ir2))
2011 Aug 16
3
Newbie question - struggling with boxplots
Hopefully I will not be flamed for this on the list, but I am starting out
with R and having some trouble with combining plots.
I am playing with the famous iris dataset (checking out example dataset in R
while reading through Introduction to datamining)
What I would like to do is create three graphs (combined boxplots) besides
each other for each of the three species (Setosa, Versicolour and