similar to: Conditional merging in R & if then statement

Displaying 20 results from an estimated 300 matches similar to: "Conditional merging in R & if then statement"

2012 Aug 29
2
Deduping in R by multiple variables
I have a dataset w/ 184K obs & 16 variables. In SAS I proc sort nodupkey it in seconds by 11 variables. I tried to do the same thing in R using both the unique & then the !duplicated functions but it just hangs there & I get no output. Does anyone know how to solve this? This is how I tried to do it in R: detail3 <-
2007 Jul 17
1
fit a nonlinear model using nlm()
I am trying to fit a nonlinear model using nlm(). My application of nlm() is a bit complicated. Here is the story behind the model being fit: The observer is trying to detect a signal corrupted by noise. On each trial, the observer gets stim=signal+rnorm(). In the simulation below I have 500 trials. Each row of stim is a new trial. On each trial, if the cross-correlation between the stim and the
2012 Dec 02
1
Repeated-measures anova with a within-subject covariate (or varying slopes random-effects?)
Dear all, I am having quite a hard time in trying to figure out how to correctly spell out a model in R (a repeated-measures anova with a within-subject covariate, I guess). Even though I have read in the posting guide that statistical advice may or may not get an answer on this list, I decided to try it anyway, hoping not to incur in somebody's ire for misusing the tool. For the sake of
2011 Feb 16
1
read.table - reading text variables as text
Hi I'm reading a CSV file using read.table, and it keeps importing a text variable as a factor. To overcome this, I've used the as.is command referring to the variable in question (called "stim") data<-read.table(file.choose(), header=T, sep=",", as.is = "stim") However, "stim" is still imported as a factor. I notice there are other read.table
2009 Dec 08
4
lower.tail option in pnorm
Hi, I would have thought that these two constructions would produce the same result but they do not. Resp <- rbinom(10, 1, 0.5) Stim <- rep(0:1, 5) mm <- model.matrix(~ Stim) Xb <- mm %*% c(0, 1) ifelse(Resp, log(pnorm(Xb)), log(1 - pnorm(Xb))) pnorm(as.vector(Xb), lower.tail = Resp, log.p = TRUE) > ifelse(Resp, log(pnorm(Xb)), log(1 - pnorm(Xb))) [1] -0.6931472 -1.8410216
2012 Oct 10
3
How to replicate SAS by group processing in R
Hello, I am trying to re-code all my programs from SAS into R. In SAS I use the following code: proc sort data=upper; by tdate stock_symbol expire strike; run; data upper1; set upper; by tdate stock_symbol expire strike; if first.expire then output; rename strike=astrike; run; on the following data set: tdate stock_symbol expiration strike 9/11/2012 C 9/16/2012
2012 Oct 19
4
Creating a new by variable in a dataframe
Hello, I have a dataframe w/ 3 variables of interest: transaction,date(tdate) & time(event_tim). How could I create a 4th variable (last_trans) that would flag the last transaction of the day for each day? In SAS I use: proc sort data=all6; by tdate event_tim; run; /*Create last transaction flag per day*/ data all6; set all6; by tdate event_tim; last_trans=last.tdate; Thanks
2011 Feb 28
1
Creating new variables. How do you get them into a data frame?
Hi I'm an R newbie. I can't seem to add new variables to data frames. Here are the stages (1) I import the data using read.csv. (2) I fix it using fix(data) (3) I create a new variable using spos<-tagPOS(stim,language="en",model=NULL,tagdict=NULL). (tagPOS is a function in the OpenNLP toolkit, which tags a string for part of speech. "stim" is a variable in the
2018 Apr 15
4
Adding a new conditional column to a list of dataframes
Hi all .., I have a list of 7000 dataframes with similar column headers and I wanted to add a new column to each dataframe based on a certain condition which is the same for all dataframes. When I extract one dataframe and apply my code it works very well as follows :- First suppose this is my first dataframe in the list > OneDF <- Mylist[[1]] > OneDF ID Pdate
2018 Mar 29
1
Problem with my function using as.POSIXct
Hello all: I wrote a function: my.bastimeToSynoptic <- function(x) { f<-unlist(strsplit(as.character(x), " ")) hr<-unlist(strsplit(f[2], ":")) if(as.numeric(hr[1])<6) { synoptic<-"00" } else { synoptic<-as.integer(as.numeric(hr[1])/6)*6 } tdate<-paste(c(f[1],"
2013 Jun 07
1
Function nlme::lme in Ubuntu (but not Win or OS X): "Non-positive definite approximate variance-covariance"
Dear all, I am estimating a mixed-model in Ubuntu Raring (13.04¸ amd64), with the code: fm0 <- lme(rt ~ run + group * stim * cond, random=list( subj=pdSymm(~ 1 + run), subj=pdSymm(~ 0 + stim)), data=mydat1) When I check the approximate variance-covariance matrix, I get: > fm0$apVar [1] "Non-positive definite
2015 Nov 06
2
(sin asunto)
Hola a tod en s, sigo intentando representar una variable en función de meses. En la columna Mesos tengo los meses de la siguiente manera: 01/08/1996, 01/09/1996 etc. He probado con el siguiente comando: plot(Mesos, Serie01) obteniendo y tendría que obtener: [image: Imágenes integradas 2] Pero donde pone Observation Index, me gustaria tener los meses (para esta grafica he usado
2011 Mar 22
1
how to convert a data.frame to a list of dist objects for individual differences MDS?
I have a 45 x 16 data frame consisting of dissimilarities among 10 colors, giving in each column the 45 = 10*9/2 pairwise judgments for one of 16 subjects. The rownames identify each pair of colors, e.g, "AC" = ("A","C"), and the pairs are ordered by columns in the lower triangle of each distance matrix. > helm.raw <-
2018 Apr 15
0
Adding a new conditional column to a list of dataframes
> On Apr 15, 2018, at 4:08 AM, Allaisone 1 <Allaisone1 at hotmail.com> wrote: > > > Hi all .., > > > I have a list of 7000 dataframes with similar column headers and I wanted to add a new column to each dataframe based on a certain condition which is the same for all dataframes. > > > When I extract one dataframe and apply my code it works very well as
2013 Jul 20
1
how to calculate the average values of each row in a matrix
Hello, I have a matrix (class matrix) composed of GridCell (row and column). The matrix value is the beta diversity index value between two grids. Now I would like to get the average value of each GridCell. Please kindly advise how to make the calculation. Thank you. Elaine The matrix looks like (cited from Michael Friendly) I would like to get the average value of each color. Obs
2009 Sep 29
2
rbind for a list
Dear All, I´m using the following code: all1<-gg2[[1]][[1]]; for(i in 1:48){ all1 <- rbind(all1,gg2[[i]][[1]]) } to create a new matrix that contains all the matrices in a list called gg2. gg2 is a list that looks like >> gg2 [[1]] [[1]][[1]] <matrix one> [[2]] [[2]][[1]] <matrix two> . . . [[48]] [[48]][[1]] <matrix 48> Is there a faster way to do the rbind?
2010 Sep 17
7
removing specific rows from array
I'm attempting to create an array of treatment comparisons for modelling data generation. This involves comparison of one treatment (c2) with another (c3), relative to a common comparator (c1). Attached code gives me the correct array but need to remove duplicates. Duplicates relate only to c2 and c3 such that I need to remove r3 because c2 and c3 are same as r1 with c2 and c3 swapped r5
2007 Nov 06
1
Problem with a non-factor, non-numeric variable in a data.frame
Dear R list, I would like to perform an ANOVA in a set of measurements, but I have problems formatting the data. The data is a two dimensional array containing two columns: - "Stim" : the type of stimulation (string) - "Ratio" : a ratio of two numeric values Now, because some values are missing in the data (defaulting to zero), part of this array will be populated with NA
2000 Oct 26
1
competing risks survival analysis
I will have data in the following form: Time resp type stim type 300 a A 200 b A 155 a B 250 b B 80 c A 1000 d B ... c is left censored observation; d is right censored This sort of problem is discussed in Chap 9 of Cox & Oakes Analysis of Survival Data under the name
2013 Apr 03
5
Can package plyr also calculate the mode?
I am trying to replicate the SAS proc univariate in R. I got most of the stats I needed for a by grouping in a data frame using: all1 <- ddply(all,"ACT_NAME", summarise, mean=mean(COUNTS), sd=sd(COUNTS), q25=quantile(COUNTS,.25),median=quantile(COUNTS,.50), q75=quantile(COUNTS,.75), q90=quantile(COUNTS,.90), q95=quantile(COUNTS,.95), q99=quantile(COUNTS,.99) )