search for: elenichri

Hi list! I have recently tried to take my office work home, meaning that I tried to transfer my "... .RData" workspace from my PC on my laptop. The office PC runs on Windows XP and my laptop runs on Windows Vista. I have saved the workspace at the office PC and kept it in a usb drive. When I tried to open it on my laptop I got an error: "Fatal Error: Unable to restore saved data in

Hello list, I am trying to apply the paired t.test between diseased and not diseased patients to identify genes that are more expressed in the one situation under the other. In order to retrieve the genes that are more expressed in the positive disease state I do: p.values<-c() for(i in 1:length(Significant[,1])){ p.values[i]<-try(t.test(positive[i,],negative[i,],alternative

Hi all, I am trying to draw a Kaplan-Meier curve and I found online that Kaplan - Meier estimates are computed with a function called km in the event package. Is there an update for that because when I choose to download packages in R,. there is no package called event, even though I have selected all the repositories. Thanks in advance, Eleni [[alternative HTML version deleted]]

Hello everyone, I wanted to know if it was possible to change the color of certain leaves in a hclust object in order to make my graph more readable. I know I can color certain groups but I would like to enter a vector telling the plot function which leaves to color in which color. Thanks in advance, Eleni [[alternative HTML version deleted]]

Hello list! I have a proble trying to perform a SAM analysis using the function samr from the samr package. I have put the option *center.arrays=TRUE *in order to scale all the experiments to median=0. I would like to retrieved the scaled data but it seems that samr does not return it...Does anyone have any idea on this? Thanks a lot!!! E. [[alternative HTML version deleted]]

Hello all, I have the following problem. I want to insert blank rows in an data frame so as to make it comparable with another data frame with more rows. How can I insert these rows? If this is not solvable, then, alternatively, is it easy to delete rows from a data frame? Thanks for helping, Eleni [[alternative HTML version deleted]]

Dear list, I am having a set of human oligo ids (H200006022 H200002025 H300004703 H200000442 H200005719 H300018350) which I want to map to Ensembl or RefSeq. I am sure R has a function to do that. I downloaded the {oligo} package and tried to use the probeNames function. Although the factor of ologo ids is an object (as the argument to probeNames should be) I retrieve the following error:

...ady got almost what I wanted. I have some NA values but I will look if I can find them through bibliography or an external tool. Best Regards, Eleni On Mon, May 19, 2008 at 6:07 PM, Sean Davis <sdavis2@mail.nih.gov> wrote: > On Mon, May 19, 2008 at 10:47 AM, Eleni Christodoulou > <elenichri@gmail.com> wrote: > > Dear list, > > > > I am having a set of human oligo ids (H200006022 H200002025 H300004703 > > H200000442 H200005719 H300018350) which I want to map to Ensembl or > RefSeq. > > I am sure R has a function to do that. I downloaded the {oligo} p...

Hello R community, I am processing raw Affymetrix CEL files and I am using the Michigan custom CDF library hgu133plus2hsentrezgprobe. I have been looking for documentation on the function that it contains...I am specifically interested in converting probe names to gene symbols. Does anybody know where I can find it? Thank a lot! Eleni [[alternative HTML version deleted]]

Dear list, I am trying to perform a significance analysis of a microarray experiment with survival data using the {samr} package. I have a matrix containing my data which has 17816 rows corresponding to genes, and 286 columns corresponding to samples. The name of this matrix is data.matrix2. Some of the first values of this matrix are: data.matrix2[1:3,1:5] GSM36777 GSM36778 GSM36779

Hi all! I am new to R and I would like to ask you the following question:How can I substitute the NA values with 0 in a data frame? I cannot find a command to check if a value is NA... Thank you very much! Eleni

Hi all, I am trying to install the package "GEOquery" in unix. I have downloaded the standard version of R and this package is not contained in the default. I know that I can select repositories under windows but I don't know how to do it in unix. Does anyone have any idea on this? Thank you in advance, Eleni [[alternative HTML version deleted]]

Hello R users, I am trying to run a cox model for the prediction of relapse of 80 cancer tumors, taking into account the expression of 17000 genes. The data are large and I retrieve an error: "Cannot allocate vector of 2.4 Mb". I increase the memory.limit to 4000 (which is the largest supported by my computer) but I still retrieve the error because of other big variables that I have in

Dear list, I have been searching for a week to fit a simple linear model to my data. I have looked into the previous posts but I haven't found anything relevant to my problem. I guess it is something simple...I just cannot see it. I have the following data frame, named "data", which is a subset of a microarray experiment. The columns are the samples and the rows are the probes. I

...man/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ------------------------------ Message: 2 Date: Wed, 21 Nov 2007 13:15:32 +0200 From: "Eleni Christodoulou" <elenichri at gmail.com> Subject: [R] NA values To: "r-help at r-project.org" <r-help at r-project.org> Message-ID: <2293b7660711210315k3c7f1a83v1ed7ff2d3f161adb at mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Hi all! I am new to R and I would like to ask you the...

I want to take the first row of each unique ID value from a data frame. For instance > ddTable <- data.frame(Id=c(1,1,2,2),name=c("Paul","Joe","Bob","Larry")) I want a dataset that is Id Name 1 Paul 2 Bob > unique(ddTable) Will give me all 4 rows, and > unique(ddTable$Id) Will give me c(1,2), but not accompanied by the name column.

Hello R community! I am trying to apply the cox model and thus I am creating a coxph object. I would like to retrieve the p-values from this and keep them separately in another vector. I can see them when I give a command for the result to appear. However, the p values are not in the list of values of a coxph object and I don't know how to keep them for future reference. Could anybody help me

Hello all, I am working at the FORTH institute in Crete and it's been a long now that I am trying to reproduce the results of the paper : "Gene expression profiling predits clinical outcome of breast cancer", by Van't Veer et al. It has been published in NATURE, vol 415, 31 January 2002. http://www.nature.com/nature/journal/v415/n6871/full/415530a.html I am facing some

Dear list, I am trying to build a cox model and then perform ROC analysis in order to retrieve some genes that are correlated with breast cancer. When I calculate the hazard score taking into account different numbers of genes and their coefficients ( I am trying to find the pest predictor number of genes), I retrieve from around 1 values (for few genes included ) to size of e+80 values (for many

Hello list, I am trying to perform ROC analysis and count the AUC in order to validate my results. I use package ROCR. I would like to count the AUC not under the cutoff found by "performance" but to use another cutoff that I calculate. How could I change the following command in order to get what I want? perform=performance(pred,measure="auc",x.measure="cutoff"),