search for: ttest

...t;Number of groups for t-test is not paired.") if(max(sig_test) > group) message("Group number for t-test is out of range.") data.norm.test = data.norm.zo #normalized data nrow <- nrow(data.norm.test) ncol <- ncol(data.norm.test) p.ttest = rep(NA, nrow) #parametric test -- t test p.wilcox = rep(NA, nrow) #non-parametric test -- Mann-Whitney test fold.mean <- rep(NA, nrow) mean.na <- rep(NA, nrow) mean.nb <- rep(NA, nrow) sig.peak.all = data...

We are trying to compile and run the ttest.c example that comes with R (in C:\Program Files\R\rw1081\src\library\windlgs\src\ttest.c). After compiling it with MS Visual C++ we load the DLL with dyn.load. So far it seems good, but when we try to call it from R (after running C:\Program Files\R\rw1081\src\library\windlgs\R\windlgs.R) R cras...

..., "201-300", "301-400", "401-500", "501-600", "601-700", "701-800", "801-900", "901-1000"), class = "factor"), MCM.Cell.vs.MCM.Tumor = c(6L, 7L, 12L, 9L, 13L, 7L, 11L, 4L, 8L, 11L, 11L, 12L, 4L, 15L, 28L ), Ttest.Tumor.vs.Ttest.Cell = c(4L, 2L, 7L, 9L, 8L, 10L, 4L, 7L, 8L, 7L, 5L, 7L, 4L, 5L, 9L), Ttest.Cell.vs.MCM.Cell = c(66L, 22L, 14L, 7L, 11L, 6L, 12L, 7L, 9L, 8L, 7L, 9L, 9L, 5L, 20L), Ttest.Tumor.vs.MCM.Tumor = c(31L, 18L, 8L, 12L, 5L, 8L, 5L, 8L, 9L, 8L, 10L, 12L, 13L, 8L, 18L)), .Names =...

Hello ... I've noticed that some of our Bioconductor code was running drastically slower under current R-devel vs. current R-patched - one example is below using a ttest. I have the following snippet of code that demonstrates the problem while avoiding "real" code that takes an extremely long time to finish on R-devel: library(genefilter) data(eset) eset$cov1 z <- ttest(eset$cov1, p=0.01) gf <- filterfun(z) system.time(genefilter(eset, gf)) (this...

...(guess there might be better ways, please suggest) and find a steady state matrix after n=30. But if I run the code with n=100 or more I get "Inf" for all entities in L. Does anyone know why is that? The code I use look like this #------------------------------------ rep<-20 T <- Ttest for(i in 1:rep){ print(i) T<-T%*%Ttest Ttest<-T } L<-T print(L) #----------------------------------

...ml#options2 and I used the suggestion provided by Jorge with modifications to my data do.call(c,lapply(your_list_with_the_t_tests,function(x) x$p.value)) but I am getting the following error after excuting the code B<-by(eo,eo$PlateID, function(.sub) t.test(mcp1~Self_T1D,data=.sub, na.rm=T)) #ttest platewise do.call(c,lapply(B, function(x) x$p.value)) Error in do.call(c, lapply(B, function(x) x$p.value)) : 'what' must be a character string or a function here "B" is equal to "your_list_with_the_t_tests. is something i am doing wrong > -- View this message in co...

Hello, I would like to do a large number of e.g. 1000 paired ttest using the by-function. But instead of using only the data within the 1000 groups, R caclulates 1000 times the ttest for the full data set(The same happens with Wilcoxon test). However, the by-function works fine with the lme function. Did I just miss something or is it really not working? If not, i...

...ent of the list that have been process every 10%. However, I can't seem to figure out a way to achieve that. For instance, I have a list of 50,000 slots: aList <- replicate(50000,list(rnorm(50))) That need to be process through the following custom function: myFnc <- function(x){ tTest <- t.test(x) return(list(p.value=tTest$p.value,t.stat=tTest$stat)) } Using an lapply statement, as in: myResults <- lapply(aList, myFnc) The goal would be to report on the progress of the lapply() function during processing. Any suggestion would be greatly appreciated. Thanks Marco...

...ust installed "rw1040" and all the components necessary to compile packages for windows. I always try out my new installation on the provided package "windlgs" in order to ensure that everything is working. This time I ran into a small problem. Indeed, the second line of "ttest.c" includes a header file ("ga.h") which does not exits. I believe that it should be changed back to what it was under "rw1031" which was "graphapp.h". Apologies if this has already been reported. Patrick. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-...

Dear list, i am a biologist who needs to do some ttest between disease and non disease, sex, genotype and the serum levels of proteins on a large number of individuals. i have been using excel for a long time but it is very tedious and time consuming. i am posting the data below and ask your help in generating a code to get this analysis done in R. tha...

...tly 2 levels". Self_T1D has two levels "N" and "Y" I have used the ddply function to do the mean and sd for the same dataframe without any issues. I would appreciate help to solve this. Thanks Sharad -- View this message in context: http://r.789695.n4.nabble.com/error-for-ttest-tp3448056p3448056.html Sent from the R help mailing list archive at Nabble.com.

...sample(controlall,100) case <- sample(caseall,100) or[i] <- round(mean(case)*(1-mean(control))/(mean(control)*(1-mean(case))),digit=2) if (or[i]<criteria[k,2]&or[i]>=criteria[k,1]) { group <- c(rep(1,100),rep(0,100)) value <- c(case,control) ttest <- (t.test(case,control,alternative="two.sided",paired=F))$p.value all <- c(or[i],ttest) results <- rbind(results,all) } ifelse(nrow(results)==5,break,1) } results1 <- rbind(results1,results) } Thank you so much in advance, Amber [[alternative HTM...

Greetings all, I am getting this error that is driving me nuts... (not a long trip, haha) I have a set of files and in these files I want to calculate ttests on rows 'compareA' and 'compareB' (these will change over time there I want a variable here). Also these files are in many different directories so I want a way filter out the junk... Anyway I don't believe that this is related to my errors but I mention it none the less. &gt...

Has anyone managed to get this working? Here's what I did: I got the binary build for R2.0.1 from the Omegahat download page, and made a small change to the registerClassID function ( to make it use the right path to RDCOMServer.dll). Then I tried to replicate the simple TTest example from the same web site. The COM class definition and registration worked fine for me. To test this, I tried to create the COM object using COMCreate ( from the RDCOMClient package ): COMCreate('R.TTest') -- this causes an error saying "Error in the DLL". In other words it...

..._TIME=English_United Kingdom.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] chron_2.3-21 zoo_1.4-2 loaded via a namespace (and not attached): [1] grid_2.6.1 lattice_0.17-2 tools_2.6.1 ###Import data: ttest<-read.csv("la_time_test2.csv", header = T, as.is=TRUE); tlist<-read.csv("la_time_list2.csv", header = T, as.is=TRUE) ####Convert to zoo: zooreg_time<-zoo(, as.chron(strptime(tlist$a_datetime, format="%d/%m/%Y %H"), format = c(dates = "Y-m-d ", tim...

In discussing permutation tests, _Modern Applied Statistics With S Plus_ suggests this (IMHO) rather elegant approach to generating a distribution of t-tests: d<- ...some data... ttest <- function(x) mean(x)/sqrt(var(x)/length(x)) n<-1000 res<-numeric(n) for(i in 1:n) res[i] <- ttest(x<-d*sign(runif(10)-0.5) The problem is that the sign(runif) results in random permutation of the observations into two groups of random size. For my analysis, however, I want to fix...

Hello, I've a data frame with 15 colums and 6000 rows, and I need the data in a single vector of size 90000 for ttest. Is there such a conversion function in R, or would I have to write my own loop over the colums? thanks for your help + kind regards Arne

...(samp1, samp2,alternative = c("two.sided"), exact = TRUE) pw.test[i] <- (test2$p.value < 0.05) test3 <- ks.test(samp1, samp2,alternative = c("two.sided"), exact = TRUE) pks.test[i] <- (test3$p.value < 0.05) } pow.ttest[j] <- sum(pt.test)/sim.size # Calculate powers for jth setting pow.wtest[j] <- sum(pw.test)/sim.size pow.kstest[j] <- sum(pks.test)/sim.size } # End of j loop Error in pt.test[i] <- (test1$p.value < 0.05) : object "pt.test" not found Chat on a cool,...

...user, I am trying to understand this following code. Basically it's using a permutation method to calculate p value. But I would like to know exactly how the permutation works. #calculates null statistics tt0 <- 0 set.seed(123) B <- 100 for(i in 1:B) { v <- sample(y) tt0 <- c(tt0,ttest(dat,v)$tt) } tt0 <- tt0[-1] #form p-values att <- abs(tt) att0 <- abs(tt0) v <- c(rep(T,m),rep(F,m*B)) v <- v[rev(order(c(att,att0)))] u <- 1:length(v) w <- 1:m p <- (u[v==TRUE]-w)/(B*m) p <- p[rank(-att)] For some reason, I couldn't get any results for p. Maybe R en...

...oject with many contributors. Type "?contributors" for a list. Type "demo()" for some demos, "help()" for on-line help, or "help.start()" for a HTML browser interface to help. Type "q()" to quit R. [Previously saved workspace restored] > ttest <- function(x){ + y <- numeric(1) + zz <- .C("test",as.integer(x),as.integer(y)) + zz[[2]] + } > dyn.load("test.so") > ttest(8) [1] 10 > > ## cntrl-C cntrl-C Program received signal SIGINT, Interrupt. 0x4012ec7e in select () from /lib/libc.so.6 (...