Displaying 20 results from an estimated 200 matches similar to: "stuck with affy / limma"
2011 Nov 22
2
filtering probesets with Bioconductor?
Hi,
I am relatively new to R and Bioconductor and am trying to filter the
topTable that I generated of differentially expressed genes from my
normlized eset file comprised of ~ 40 HG-133A Affy microarrays . I would
like to see if particular probesets are represented in this list.
Alternatively I would like to
generate a topTable of differentially expressed genes using only specified
probesets
2008 Sep 23
2
read.table & readLines behaviour?
Hi,
I have been using 'read.table' regularly to read tab-delimited text
files with data. No problem, until now.
Now I have a file that appeared to have read fine, and the data inside
looks correct (structure etc), except I only had 15000+ rows out of
the expected 24000. Using 'readLines' instead, and breaking up the
data by tabs, gives me the expected result.
I do not
2008 Mar 04
2
paired or one-sample t-Test
Hi Guys,
I am having a real hard time trying to figure out for microarry.
Here is my code
One-Sample t-Test
dim(data.sub)
[1] 10000 140 ##there are 10000 probesets and 140 columns
hist(data.sub) ## Histogram. Identify if the probesets are normal
distributed
q<-rnorm(10000) ##generate 10000 random, normal distributed values
qqplot(data.sub,q)) ##Show the plot of the probeset
2003 Dec 22
2
Memory allocation
Hello:
I am trying to work with a couple of microarray data sets, using
platform i386-pc-mingw32
arch i386
os mingw32
system i386, mingw32
status
major 1
minor 8.1
year 2003
month 11
day 21
language R
In the shortcut for invoking R I have set
2011 Aug 31
3
subsetting by rows
Dear all,
I would like to know how to subset a data.frame by rows.
Example:
Probesets 34884 34888 34892
1 100009676_at A A A
2 10001_at P P P
3 10002_at A A A
4 10003_at A A
2009 Dec 26
1
[BioC] How to do RMA without summary to probeset level?
I think that you misunderstood me.
As far as I know, RMA does three things: background correction,
quantile normalization, and summary from probes to probesets. I want
the probe values after background correction and quantile
normalization but before the summary.
On Sat, Dec 26, 2009 at 12:07 PM, Benilton Carvalho <bcarvalh at jhsph.edu> wrote:
> pm(data)
>
> b
>
> On Dec
2008 Mar 03
3
R data Export to Excel
Here is my R Code
x<-1:20000
y<-2:141
data.matrix<-data.matrix(data[,y])#create data.matrix
variableprobe<-apply(data.matrix[x,],1,var)
variableprobe #output variance across probesets
hist(variableprobe) #displaying histogram of variableprobe
write.table(cbind(data[1],
Variance=apply(data[,y],1,var)),file='c://variance.csv')
#export as a .csv file.
Output in Excel
all in 1
2005 Aug 31
1
Bioconductor and R-devel
Hi,
I have built R (current development version) and BioConductor 1.7
with portland group compiler on a AMD Opteron.
When I ran qc assessment on Affymetrix latin square data set, I got the
following output,
Loading required package: affy
Loading required package: Biobase
Loading required package: tools
Welcome to Bioconductor
Vignettes contain introductory material. To view,
2011 Apr 09
3
In need of help with correlations
I am in need of someone's help in correlating gene expression. I'm somewhat
new to R, and can't seem to find anyone local to help me with what I think
is a simple problem.
I need to obtain pearson and spearman correlation coefficients, and
corresponding p-values for all of the genes in my dataset that correlate to
one specific gene of interest. I'm working with mouse Affymetrix
2008 Mar 03
3
Calculating the t-test for each row
Hi Everyone,
I need some simple help.
Here are my codes
##########will give me 10000 probesets####################
data.sub = data.matrix[order(variableprobe,decreasing=TRUE),][1:10000,]
dim(data.sub)
data_output<-write.table(data.sub, file = "c://data_output.csv", sep = ",",
col.names = NA)
When i export to excel, it shows me this. This is just a short version.
There
2008 Feb 19
1
Calculating the distance samples using distance metics method
***********reading in data**********
data<-read.table("microarray.txt",header=T, sep="\t")
head(data)
dim(data)
attach(data)
***********creating matrix and calculating variance across probesets********
x<-1:20000
y<-2:141
data.matrix<-data.matrix(data[,y])
variableprobe<-apply(data.matrix[x,],1,var)
hist(variableprobe)
**************filter out low
2013 Apr 03
1
Select single probe-set with median expression from multiple probe-sets corresponding to same gene -AFFY
Hello All,
I need your help. I am analysing affymetrix data and have to select the
probe-set that has median expression among all the probe-sets for same
gene. This way I want to remove the redundancy by keeping the analysis
to single gene entry level. I am fully aware that it is not a nice thing
to do but I just have to do it.
To do so, I came across 'findLargest' function of
2008 Mar 04
1
Export csv data
Hi Everyone,
Thanks for all the help with the previous queries.
Here is what i want to do. i have 20000 probesets-->calculate all the
variance accross all the probesets-->filter out probesets that are low so
now i ended up with only 10000. The 10000 is fine but when i export to
excel, it is missing the probeID. Here are my code and examples.
#########calculate the variance across the
2009 Dec 08
1
read.affy.mixed - subscript out of bounds error
Hello,
I have a problem with read.affy.mixed function. I want to read in
together a set of CEL files from chip types Affymettrix HGU133A_2 and
HGU133_Plus_2. I have my files to be read in in one directory together
with a white space delimited file describing them (covdesc). In this
directory I give a command:
> merge <- read.affy.mixed()
Error in merged[[i]] : subscript out of
2012 Apr 03
2
how to map microarray probe to gene, homology
Hi:
I have clustered microarray gene expression data and trying to map between
microarray probe, gene, pathway, gene ontology, and homology for a set of
(affy) microarray probes. Is there any package in R which facilitates this?
I am looking at bioconductor, but till now could not find a solution. A
link to some worked example would be appreciated.
Thanks and regards.
John
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2012 May 11
3
Calculating all possible ratios
I have a data matrix with genes as columns and samples as rows. I want to
create all possible gene ratios.Is there an elegant and fast way to do it in
R and write it to a dataframe?
Thanks for any help.
Som.
--
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Sent from the R help mailing list archive at Nabble.com.
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2010 Aug 25
3
approxfun-problems (yleft and yright ignored)
Dear all,
I have run into a problem when running some code implemented in the
Bioconductor panp-package (applied to my own expression data), whereby gene
expression values of known true negative probesets (x) are interpolated onto
present/absent p-values (y) between 0 and 1 using the *approxfun -
function*{stats}; when I have used R version 2.8, everything had
worked fine,
however, after updating
2011 Feb 24
1
Group rows by common ID and plot?
Suspect that this is easier than I realize, but taking some figuring out
currently. Any help would be appreciated.
I have a data frame (testhm) with many rows such as:
ProbeSet.ID.F ProbeSet.ID Feature.ID G.S X0030V120810.14 X0143V120110.14
X0258V111710.14 X0283V111710.14 X0430V120710.14 X0472V111610.14
X0520V111610.14 X0546V113010.14 X0578V111810.14 X0624V111810.14
2 7892501_943979
2006 Nov 06
1
colnames and get means for the columns with the "same" names
hi,
I have a conversion table for colnames like this:
Probe_ID HUMAN_LLID
1 AF106325_PROBE1 7052
2 NM_019386_PROBE1 7052
3 NM_012907_PROBE1 339
4 AW917796_PROBE1 84196
5 L27651_PROBE1 10864
The Probe_ID contains a list of colnames for another data.frame, say x1.
I need to convert such colnames to another ID's system, HUMAN_LLID by
using the table.
2002 Oct 29
0
PCA with n << p (was R-1.6.0 crashing on RedHat6.3)
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We have also encountered the problem Douglas