Displaying 20 results from an estimated 20000 matches similar to: "split and subset"
2008 May 03
2
help with subset
Dear list:
I have a problem using the subset function:
dat<- data.frame(treatment=c("A", "B", "A", "C", "C", "D", "A", "D",
"C", "D"), response=rnorm(10))
I am interested in treatments "A", "B" and "D"
vec<- c("A", "B", "D")
But I
2002 Jul 09
3
Assignment converts variable to factor
Hello,
I would like to know if this behaviour in R is as expected.
I have a data frame 'dat' with column var1 being character (and not
factor). Then I create a new column 'var2' by:
> dat[,"var2"] <- dat$var1;
Column var2 is now a factor.
But if I do:
> dat$var2 <- dat$var1;
Then column var2 is character (and not factor).
I don't want to have
2009 May 20
1
Comparing spatial distributions - permutation test implementation
Hello everyone,
I am looking at the joint spatial distribution of 2 kinds of organisms
(estimated on a grid of points) and want to test for significant
association or dissociation.
My first question is: do you know a nice technique to do that,
considering that I have a limited number of points (36) but that they
are repeated (4 times)? I did GLMs to test for correlations between
the
2009 Jan 13
3
Comparing elements for equality
Suppose I have a dataframe as follows:
dat <- data.frame(id = c(1,1,2,2,2), var1 = c(10,10,20,20,25), var2 =
c('foo', 'foo', 'foo', 'foobar', 'foo'))
Now, if I were to subset by id, such as:
> subset(dat, id==1)
id var1 var2
1 1 10 foo
2 1 10 foo
I can see that the elements in var1 are exactly the same and the
elements in var2 are exactly
2012 Jan 10
4
Sum of a couple of variables of which a few have NA values
Dear everyone,
I have looked all over the internet but I cannot find a way to solve my problem.
In my data I want to sum a couple of variables. Some of these
variables have NA values, and when I add them together, the result is
NA
dat <- data.frame(
id = gl(5,1),
var1 = rnorm(5, 10),
var2 = rnorm(5, 7),
var3 = rnorm(5, 6),
var4 = rnorm(5, 3),
var5 = rnorm(5, 8)
)
dat[3,3] <- NA
dat[4,5]
2007 Apr 02
3
Create a new var reflecting the order of subjects in existing var
Dear R helpers
I have a data set sth like this:
set.seed(123);dat <- data.frame(ID= c(rep(1,2),rep(2,3), rep(3,3), rep(4,4),
rep(5,5)),
var1 =rnorm(17, 35,2),
var2=runif(17,0,1))
dat
ID var1 var2
1 1 33.87905 0.02461368
2 1 34.53965 0.47779597
3 2 38.11742 0.75845954
4 2 35.14102 0.21640794
5 2 35.25858 0.31818101
6 3 38.43013
2017 Sep 25
0
Sample of a subsample
For personal aesthetic reasons, I changed the name "data" to "dat".
Your code, with a slight modification:
set.seed (1357) ## for reproducibility
dat <- data.frame(var1=seq(1:40), var2=seq(40,1))
dat$sampleNo <- 0
idx <- sample(seq(1,nrow(dat)), size=10, replace=F)
dat[idx,"sampleNo"] <-1
## yielding
> dat
var1 var2 sampleNo
1 1 40
2017 Sep 25
1
Sample of a subsample
Hi David,
I was about to post a reply when Bert responded. His answer is good
and his comment to use the name 'dat' rather than 'data' is instructive.
I am providing my suggestion as well because I think it may address
what was causing you some confusion (mainly to use "which", but also
the missing !)
idx2 <- sample( which( (!data$var1%%2) & data$sampleNo==0 ),
2005 Apr 29
2
Automating plot labelling in custom function in lapply() ?
Dear List,
Consider the following example:
dat <- data.frame(var1 = rnorm(100), var2 = rnorm(100),
var3 = rnorm(100), var4 = rnorm(100))
oldpar <- par(mfrow = c(2,2), no.readonly = TRUE)
invisible(lapply(dat,
function(x) {
plot(density(x),
main = deparse(substitute(x))) }
)
)
2010 Sep 10
1
adding labels above bars in a barplot
Hello,
I want to make a general routine to draw barplots with numbers plotted
above each bar. See the example below.
I could not place the numbers on the middle of each bar because I
could not calculate the right position of each x-axis tick. axTicks(1)
indicated a unitary step, but it does not seem work.
I appreciate any help or suggestions.
Best regards,
Antonio Olinto
2010 Jul 09
2
split with list
Dear List I would like to ask you something concenting a better print of the R output:
I have a bit data frame which has the following structure:
CFISCALE RAGSOCB ANNO VAR1 VAR2.........
9853312 astra 2005 6 45
9853312 astra 2006 78 45
2009 Jun 16
1
Running stats on individual data.frames from the split() function list
Hello, and thanks in advance.
I have a data.frame from which I want to count observations that occur
on each day and determine the mean and std.error of said counts.
For instance:
x<-split(my.df, my.df$julian.days)
Although I'm still in my R learning infancy I am under the impression
that x is a list of data.frames subsetting my.df by group
(i.e.,julian.day) where day 1:366 are
2007 Apr 03
1
Behavior of seq_along (was: Create a new var reflecting the order of subjects in existing var)
I am moving this from r-help to r-devel. Based on offline communications
with Jim, suppose dat is defined as follows:
set.seed(123)
dat <- data.frame(ID= c(rep(1,2),rep(2,3), rep(3,3), rep(4,4),
rep(5,5)), var1 =rnorm(17, 35,2), var2=runif(17,0,1))
# Then this ave call works as expected:
ave(dat$ID, dat$ID, FUN = function(x) seq_along(x))
# but this apparently identical calculation
2008 Oct 10
1
Correlation among correlation matrices cor() - Interpretation
Hello,
If I have two correlation matrices (e.g. one for each of two treatments) and
then perform cor() on those two correlation matrices is this third
correlation matrix interpreted as the correlation between the two
treatments?
In my sample below I would interpret that the treatments are 0.28
correlated. Is this correct?
> var1<- c(.000000000008, .09, .1234, .5670008, .00110011002200,
2012 Oct 17
2
loop of quartile groups
Greetings R users,
My goal is to generate quartile groups of each variable in my data set. I
would like each experiment to have its designated group added as a
subsequent column. I can accomplish this individually with the following
code:
brks <- with(data_variables,
cut2(var2, g=4))
#I don't want the actual numbers, I need a numbered group
data$test1=factor(brks,
2011 May 01
2
bwplot in ascending order
Can anyone point me to examples with R code where bwplot in lattice is used to order the boxes in ascending order? I have found the following discussion and it partly works. But, I have a conditioning variable, so my example is more like
bwplot(var1 ~ var2|condition, dat)
Th example in the discussion below works only when there is not a conditioning variable as far as I can tell. I can tweak the
2012 Oct 19
1
Looping survdiff
The number of recent questions from umn.edu makes me wonder if there's homework involved....
Simpler for your example is to use get and subset.
dat <- structure(..... as found below
var.to.test <- names(dat)[4:6] #variables of interest
nvar <- length(var.to.test)
chisq <- double(nvar)
for (i in 1:nvar) {
tfit <- survdiff(Surv(time, completion==2) ~
2012 Oct 18
1
looping survdiff?
Hello,
I am trying to set up a loop that can run the survdiff function with the
ultimate goal to generate a csv file with the p-values reported. However,
whenever I try a loop I get an error such as "invalid type (list) for
variable 'survival_data_variables[i]".
This is a subset of my data:
structure(list(time = c(1.51666666666667, 72, 72, 25.7833333333333,
72, 72, 72, 72, 72,
2009 Feb 27
3
Making tapply code more efficient
Previously, I posed the question pasted down below to the list and
received some very helpful responses. While the code suggestions
provided in response indeed work, they seem to only work with *very*
small data sets and so I wanted to follow up and see if anyone had ideas
for better efficiency. I was quite embarrased on this as our SAS
programmers cranked out programs that did this in the blink
2012 Jan 16
3
Select rows based on multiple comparisons
Dear all,
I have a data set in which the same unit appears 2 or 3 or 4 times. I need
to aggregate this data to maintain only one unit by row. But I need to do
that based on a comparison between the values of such units. I can't find a
function to help me on that. I appreciate any help. Below I provide an
example of what I want:
This is my data:
Units Var1 Var2 Var3
1 B 2