search for: vishalthapar

Hi All, This is more of a general statistics question that I am not so sure about so I need some thoughts from you experts out there. I have Chip-Seq read count data for 2 different treatments (T1 and T2) and my final aim is to calculate differential expression between them. I also have Chip-Seq read count data from a "control / wild type (C)" experiment. I have 3 replicates (2

Hi useR's, Has anyone used the "Lars" package in R before? If so, is there any tutorial (not manual) or worked out example online for this R package that one can go through to figure out how one can use this package with lasso regression? I appreciate any help I can get in this direction. Sincerely, Vishal -- *Vishal Thapar, Ph.D.* *Scientific informatics Analyst Cold Spring

Hi, I apologize for posting this here, I am also trying to post this on machine learning emailing lists. I have a set (18K) of sequences (22 nt long) and I have their counts at 4 different stages. The difference in counts from one stage to the next represents how well the sequence performed in the transition. The total counts remain about the same in each stage. So if a 1 sequence loses some

Hi All, Did anyone else have a problem like this? I am sorry if its a small issue, I seem to not understand what to do to get rid of this error. > Sigma [1] 0.1939025 > MuRest [1] 8.512772 > TauZero [1] 0.1 > curve(qlnorm(x,-TauZero+MuRest, Sigma,lower.tail=F), xlim=c(4000,9000), ylim=c(0,.99),xlab="", ylab="") Warning message: In qlnorm(p, meanlog, sdlog,

...it replaces all the values in the sequence with "a" only. So all columns become "a". How do I fix this so that the columns retain their original values but still have 4 levels ie. a,c,g,t. Thanks a lot for your help, Vishal On Sat, Dec 26, 2009 at 10:39 AM, Vishal Thapar <vishalthapar@gmail.com>wrote: > Hi David, > > Thank you so much for the pointer. I get it now. I did try the > str(testSeq_df) and since it gave me more than 2 factors for each column, I > believed that it was fine. I get the point clearly now. Thanks again for all > your help. I really ap...

Hi useR's, I am resending this request since I got no response for my last post and I am new to the list so pardon me if I am violating the protocol. I am trying to use the "Kernlab" package for training and prediction using SVM's. I am getting the following error when I am trying to use the predict function: > predictSvm = predict(modelforSVM, testSeq); Error in

Hi, I am writing to seek some guidance regarding using Lasso regression with the R package LARS. I have introductory statistics background but I am trying to learn more. Right now I am trying to duplicate the results in a paper for shRNA prediction "An accurate and interpretable model for siRNA efficacy prediction, Jean-Philippe Vert et. al, Bioinformatics" for a Bioinformatics project

Hi All, I am trying to use the "Kernlab" package for training and prediction using SVM's. I am getting the following error when I am trying to use the predict function: > predictSvm = predict(modelforSVM, testSeq); Error in `contrasts<-`(`*tmp*`, value = "contr.treatment") : contrasts can be applied only to factors with 2 or more levels The training file is a