Displaying 20 results from an estimated 600 matches similar to: "Schmera: a question on R software"
2011 Apr 07
1
Assigning a larger number of levels to a factor that has fewer levels
Hello!
I have larger and a smaller data frame with 1 factor in each - it's
the same factor:
large.frame<-data.frame(myfactor=LETTERS[1:10])
small.frame<-data.frame(myfactor=LETTERS[c(9,7,5,3,1)])
levels(large.frame$myfactor)
levels(small.frame$myfactor)
table(large.frame$myfactor)
table(small.frame$myfactor)
myfactor has 10 levels in large.frame and 5 levels in small.frame. All
5
2009 May 06
4
tapply changing order of factor levels?
Hi,
Does tapply change the order when applied on a factor? Below is the code I
tried.
> mylevels<-c("IN0020020155","IN0019800021","IN0020020064")
>
2012 Jan 18
1
drop rare factors
I have a data frame with some factor columns.
I want to drop the rows with rare factor values
(and remove the factor values from the factors).
E.g., frame$MyFactor takes values
A 1,000 times,
B 2,000 times,
C 30 times and
D 4 times.
I want to remove all rows which assume rare values (<1%), i.e., C and D.
i.e.,
frame <- frame[[! (frame$MyFactor %in% c("A","B"))]]
except
2010 Jul 05
2
repeated measures with missing data
Dear R help group, I am teaching myself linear mixed models with missing data since I would like to analyze a stats design with these kind of models. The textbook example is for the procedure "proc MIXED" in SAS, but I would like to know if there is an equivalent in R. This example only includes two time-measurements across subjects (a t-test "with missing values"), but I
2012 Mar 28
1
discrepancy between paired t test and glht on lme models
Hi folks,
I am working with repeated measures data and I ran into issues where the
paired t-test results did not match those obtained by employing glht()
contrasts on a lme model. While the lme model itself appears to be fine,
there seems to be some discrepancy with using glht() on the lme model
(unless I am missing something here). I was wondering if someone could
help identify the issue. On
2012 Nov 24
1
Adding a new variable to each element of a list
Hello,
I have a list of data with multiple elements, and each element in the list
has multiple variables in it. Here's an example:
### Make the fake data
dv <- c(1,3,4,2,2,3,2,5,6,3,4,4,3,5,6)
subject <- factor(c("s1","s1","s1","s2","s2","s2","s3","s3","s3",
2006 Apr 29
1
splitting and saving a large dataframe
Hi,
I searched for this in the mailing list, but found no results.
I have a large dataframe ( dim(mydata)= 1297059 16, object.size(mydata=
145280576) ) , and I want to perform some calculations which can be done by
a factor's levels, say, mydata$myfactor. So what I want is to split this
dataframe into nlevels(mydata$myfactor) = 80 levels. But I must do this
efficiently, that is, I
2007 Dec 09
2
adjusting "levels" after subset a table
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2011 Mar 30
2
summing values by week - based on daily dates - but with some dates missing
Dear everybody,
I have the following challenge. I have a data set with 2 subgroups,
dates (days), and corresponding values (see example code below).
Within each subgroup: I need to aggregate (sum) the values by week -
for weeks that start on a Monday (for example, 2008-12-29 was a
Monday).
I find it difficult because I have missing dates in my data - so that
sometimes I don't even have the
2006 May 24
3
How to make attributes persist after indexing?
Dear All!
For descriptive purposes I would like to add attributes to objects. These
attributes should be kept, even if by indexing only part of the object is
used.
I noted that some attributes like levels and class of a factor exist also
after indexing, while others, like comment or label vanish.
Is there a way to make an arbitrary attribute to be kept after indexing?
This would be especially
2011 Nov 10
1
Errors in SIAR
Help!
model1 <- siarmcmcdirichletv4(data, source, tef, concdep=0, 500000, 50000)
Error in matrix(1, ncol = (numsources + numiso) * numgroups, nrow =
(siardata$iterations - :
invalid 'ncol' value (too large or NA)
In addition: Warning message:
In Ops.ordered((numsources + numiso), numgroups) :
'*' is not meaningful for ordered factors
Previous message, but more
2009 Mar 03
1
repeated measures anova, sphericity, epsilon, etc
I have 3 questions (below).
Background: I am teaching an introductory statistics course in which we are
covering (among other things) repeated measures anova. This time around
teaching it, we are using R for all of our computations. We are starting by
covering the univariate approach to repeated measures anova.
Doing a basic repeated measures anova (univariate approach) using aov()
seems
2008 Aug 29
1
R graphical question
I'm trying to create a graph using plot() with an axis that I
essentially want to plot the categories in the reverse alphanumeric
order - opposite of the typical R fashion. Is there a function to do
this?
In other words, I have categories "a", "c", "g", "z" which is the
order they'll be plotted, but I want to plot them as "z",
2005 Apr 26
2
Fresh Dovecot Install
Working on an RH9 box. Did not use yum.
Downloaded the "dovecot-stable-latest.tar.gz". Uncompressed it,
downloaded and installed gcc. Ran the following:
./configure
make
sudo make install
Seemed to have done its thing. I'll admit I am not well versed in
using "make" or compiling anything. When I install I usually use yum
on fedora machines. This one being an RH9 machine
2003 Jun 27
3
dropping factor levels in subset
Dear all,
I've taken a subset of data from a data frame using
crb<-subset(all.raw, creek %in% c("CR") & year %in% c(2000,2001) & substrate
%in% ("b"))
this works fine, except that all of the original factor levels are
maintained. This results in NA's for these empty levels when I try to do
summaries based on factors using by(). Is there a simple way to drop
2003 Jun 04
2
convert factor to numeric
Hi R-experts!
Every once in a while I need to convert a factor to a vector of numeric
values. as.numeric(myfactor) of course returns a nice numeric vector of
the indexes of the levels which is usually not what I had in mind:
> v <- c(25, 3.78, 16.5, 37, 109)
> f <- factor(v)
> f
[1] 25 3.78 16.5 37 109
Levels: 3.78 16.5 25 37 109
> as.numeric(f)
[1] 3 1 2 4 5
>
What I
2011 Mar 16
2
Numeric vector converted mysteriously to characters in data frame?
Dear R Help,
I would be very grateful if somebody could explain why this is happening. I
am trying to plot a lattice barchart of a vector of numbers with age
bandings that I have brought together into a data frame. When I plot the
variables in their raw vector form, it works. When I try to plot them in
the df, R labels the numeric axis with default factor values and treats the
numeric vector
2003 Nov 13
5
xlims of barplot
I would like to create a family of barplots with the same xlimits. Is
there a way to "read" the xlimits from the first graph so I can apply it to
the subsequent ones?
I have tried just taking the min and max of the x data and the plot doesn't
show.
cheers
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2006 Jan 30
2
Type II SS for fixed-effect in mixed model
Hi
In mixed-model with lme()
How can I obtain Type II SS or Type III SS for fixed effect?
Thanks
Julien
2003 Nov 21
3
what does this mean in R-1.8.1 release notes?
what does this mean in R-1.8.1 release notes?
o median() no longer `works' for odd-length factor variables.