similar to: assigning creating missing rows and values

I have a new device that takes measurements anywhere from every second, to every 15 minutes (depending on changes). The matrix has a date, time and Y column (Y is the measurement). For three days it is 25,000 rows. How do I average the measurements by every 30 minutes so my matrix is 48 rows per day? I have been working on this and cannot figure out a simple method. Any ideas? Thank you. ----- In

I have a combined date and time. I would like to separate them out into two columns so I can do things such as take the mean by time across all dates. meas<-runif(435) nTime<-seq(1303975800, 1304757000, 1800) nDateT<-as.POSIXct(nTime, origin="1970-01-01") mat1<-cbind(nDateT,meas) means1<- aggregate(mat1$meas, list(nDateT), mean) This doesn't do anything as each day

I have times and would like to round down to the earliest 30 minute increment. For instance, a time of 2011-04-28 09:02:00 (the as.numeric value = 1303999320) I would like it to be rounded down to: 2011-04-28 09:00:00 (the as.numeric value = 1303999200) Any ideas of how to do this? ----- In theory, practice and theory are the same. In practice, they are not - Albert Einstein -- View this

Hello! I work with : R : Copyright 2006, The R Foundation for Statistical Computing Version 2.3.1 (2006-06-01) On Windows XP Professional (Version 2002) SP2. At this moment I use the function "nls" combined with a selfStar model (SSmicmen, related to Michaelis-Menten equation, and provided by the "stats" package). When I realise the following operation (cf. p 59 of the

Sometimes I have NA values within specific columns of a dataframe (in this example, the first two columns can have NAs). If there are NA values, I would like them to be removed. I have been using the code: y<-c(NA,5,4,2,5,6,NA) z<-c(NA,3,4,NA,1,3,7) x<-1:7 adata<-data.frame(y,z,x) adata<-adata[-which(apply(adata[,1:2],1,function(x)any(is.na(x)))),] This works well if there are NA

I have encountered this problem on several occasions and am not sure how to handle it. I use for-loops to cycle through datasets. When each dataset is of equal length, it works fine as I can combine the datasets and have each loop pick up a different column, but when the datasets are differing lengths, I am struggling. Here is an example: A<-1:10 B<-1:15 C<-1:18

I am running the following nls equation. I tried it with data that excel was fitting and got the error: singular gradient matrix at initial parameter estimates I thought it was due to a low number of points (6), but when I create a dataset, I get the same problem. If I remove the parameter "a," then it can find a solution. Does anyone know what I can do to fit this model?

I would like to create a plot of y vs x with different treatments where the points are actually the letter of the treatment. Here is the code: A<-as.matrix(rnorm(10,10)) B<-as.matrix(rnorm(10,9.5)) C<-as.matrix(rnorm(10,10.5)) Y<-as.matrix(rnorm(30,13)) X<-rbind(A,B,C) nA<-matrix("A",10,1) nB<-matrix("B",10,1) nC<-matrix("C",10,1)

Is length(unique()) what you are looking for? Andy > From: Christoph Lehmann > > Hi I have a question concerning aggregation > > (simple demo code S. below) > > I have the data.frame > > id meas date > 1 a 0.637513747 1 > 2 a 0.187710063 2 > 3 a 0.247098459 2 > 4 a 0.306447690 3 > 5 b 0.407573577 2 > 6 b

I swear I've scoured the help files and several texts before posting what feels like a dumb newbie question. How can I draw two kernel density plots in the same frame ? I have similar variables in two separate data frames, and I would like to show their two histograms/densities in a single picture. Same units, scale, range for both, so I'm simply trying to draw one and then add the

I am very confused about this. I want to convert a string to a name so I can use it to extract an element of a data frame using `$'. Here is my (non-working) code: do.graph <- function (meas) { fn <- paste("a", meas, ".dat", sep='') themeas <- read.table(fn, header=F) ameas <- as.name(paste("a", meas, sep=''))

Greetings, fellow R'ers. How can I get this frame in R: ID meas ID.1 meas.1 1 1.1 3 1.2 2 2.1 4 2.2 to look like this (stacking): ID meas 1 1.1 2 2.1 3 1.2 4 2.2 It's not really the reshape function (or is it?) because we can consider the additional columns, viz., ID.1 and meas.1, as independent of ID and meas so it is basically a stacking

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Hello all, I want box plots by group to display in order of increasing mean (or median) of each group but can't seem to figure it out and couldn't find anything on R-seek, either. My data looks like this: meas unit sid grade rsprti 1 2.24 1002 99999902 NA 0.8600000 2 3.04 1007 43589520 3 0.9400000 3 4.95 2002 39910470 5 1.5300000 4 2.24 2002 39986280 5

Hello everybody. In my case, calculating multiple comparisons (Tukey) after lmer produced the following two errors: > sv.mc <- glht(model.sv,linfct=mcp(comp="Tukey")) Error in x$terms : $ operator not defined for this S4 class Error in factor_contrasts(model) : no 'model.matrix' method for 'model' found! What I have done before: > sv.growth <-

Dear R people Could you please help with following Trying to compare accuracy of tumor size evaluation by different methods. So data looks like id true metod1 method2 ... 1 2 2 2.5 2 1.5 2 2 3 2 2 2 etc. Could you please give a hint how to deal with that. Seems like {merror} does not suite to me because I am trying to compare accuracy of measurements with their true known values not just

Hello, I am trying to ask the user for which column their data is in, and then use this information in a function. So far I have: data <- read.csv(file.choose(), header=TRUE) col <- (winDialogString("Which column contains your data?","")) and I want to be able to reference such as: meas <- data$col and use this meas in the function. However, I can't seem to

Olly Betts <olly <at> survex.com> writes: > > On Thu, Jan 14, 2016 at 11:04:29AM +0100, Jean-Francois Dockes wrote: > > Olly Betts writes: > > > On Sun, Jan 10, 2016 at 02:53:14AM +0000, Bob Cargill wrote: > > > > I will look into the bug you listed to see if it might be related. If there > > > > is anything else that I can do, please

Hello, sorry for writing here because my problem is not a realt bug but may be a solution for many people working with R: I miss the feature for commenting some lines of code at once without writing a bunch of "#" in front of each line. This is interesting for trying out some code. I found some workarounds like IFELSE(FALSE){} and `!`<- function(x) { if (inherits(x,

Hello all, I am trying to understand how SAMBA finds nearest Domain Controller when configured to use Active Directory for AuthN. There are some great articles and wikis about how to configure SAMBA against AD, but couldn't find much on what I was looking for. For example 1. Does Samba have built in dc locator functionality like windows clients ? 2. What is the default authN it uses, NTLM