similar to: Subsetting a group of data

Displaying 20 results from an estimated 11000 matches similar to: "Subsetting a group of data"

2009 Jul 12
2
Nonlinear Least Squares nls() programming help
Hi, I am trying to use the nls() function to closely approximate a vector of values, colC and I'm running into trouble. I am not sure how if I am asking the program to do what I think its doing, because the same minimization in Excel's Solver does not run into problems. If anyone can tell me what is going wrong, and why I'm getting a singular convergence(7) error, please tell me. I
2008 Jun 27
2
change values in data frames
Hello every body, I am quite a new user of R so I beg your pardon for this naive question and the lake of syntax with wich I ask it: I have a data frames like this: cola colb 1 c 1 i 1 i 1 c 2 i 2 c 2 c 2 i 2 i ... 10000 I would like ,for each level of cola and for x in colb: -if colb[x]=="i" and colb[x-1] does not exist (first row in dataframes), then replace colb[x] by
2012 Jul 11
4
Help with loop
Hi, I have two dataframes: The first, df1, contains some missing data: cola colb colc cold cole 1 NA 5 9 NA 17 2 NA 6 NA 14 NA 3 3 NA 11 15 19 4 4 8 12 NA 20 The second, df2, contains the following: cola colb colc cold cole 1 1.4 0.8 0.02 1.6 0.6 I'm wanting all missing data in df1$cola to be replaced by the value of df2$cola.
2011 Aug 03
2
Error message for MCC
Greetings all, I am getting an error message that is stifling me. Any ideas? > ## Define Directories ## > load_from <- "/home/mcc/Dropbox/abrodsky/kegg_combine_data/" > save_to <- "/home/mcc/Dropbox/abrodsky/ttest_results/" > > ############################### > ## Define Columns To Compare ## > compareA <- "log_b_rich" > compareB
2013 Apr 30
2
R Function to extract columnNames
Hi, May be this helps: funcName<- function(df1, x){ ?whatCol=df1[[x]] ?print("Got it") ?print(whatCol) ?} ? funcName(df,"ColA") #[1] "Got it" #[1] 1 2 3 4 5 ? funcName(df,"ColB") #[1] "Got it" #[1] A B C D E #Levels: A B C D E A.K. >I am trying to extract the 2nd column from a dataframe using a function called funcName. Note this is an
2005 Sep 09
3
how to do something like " subset(mat, ("col1">4 & "col2">4)) "
Dear all, I have a problem with the "subset()" function. I spent all day yesterday with a collegue to solve it and we did not find a satisfying solution (even in the archived mails), so I ask for your help. Let's say (for a simple example) a matrix mat: R> mat cola colb colc [1,] 1 4 7 [2,] 2 5 8 [3,] 3 6 9 My goal is to select the lines of the matrix on the basis of the
2011 Aug 05
2
Which is more efficient?
Greetings all, I am curious to know if either of these two sets of code is more efficient? Example1: ## t-test ## colA <- temp [ , j ] colB <- temp [ , k ] ttr <- t.test ( colA, colB, var.equal=TRUE) tt_pvalue [ i ] <- ttr$p.value or Example2: tt_pvalue [ i ] <- t.test ( temp[ , j ], temp[ , k ], var.equal=TRUE) ------------- I have three loops, i, j, k. One to test the all of
2011 Jun 10
2
Sorting Data Frame Without Loop
Hello all! I am currently trying to sort a data frame in a particular way, but I am having some difficulties with this. Specifically I want to sort the below dataset in such a way that there is only one line per ProteinID and if there are multiple GeneID or GeneName entries for a single proteinID, that they be concatenated with a comma separating them. The way I have done it earlier worked fine
2013 Apr 03
2
Creating data frame from individual files
Dear Group: I have 72 files (.txt). Each file has 2 columns and column 1 is always identical for all 70 files. Each file has 90,799 rows and is standard across all files. I want to create a matrix 40(rows) x 70 columns. I tried : temp = list.files(pattern="*.txt") named.list <- lapply(temp, read.delim) library(data.table) files.matrix <-rbindlist(named.list) >
2010 Dec 09
2
Reshape Columns
Hello, I have a general formatting question. I have two columns of data: ColA <- c("m", "m", "m", "m") ColB<- c("d","d","d","d") And I would like to reorder them into a new column that looks like this: ColC<-
2006 Apr 12
0
New class: data.table
Hi, Following previous discussion on this list (http://tolstoy.newcastle.edu.au/R/devel/05/12/3439.html) I have created a package as suggested, and uploaded it to CRAN incoming : data.table.tar.gz. ** Your comments and feedback will be very much appreciated. ** >From help(data.table) : This class really does very little. The only reason for its existence is that the white book specifies
2012 Jul 11
1
sapply question
Why does this sapply code change df3 but not df1? Thanks df1 <- read.table(text=" cola colb colc cold cole 1 NA 5 9 NA 17 2 NA 6 NA 14 NA 3 3 NA 11 15 19 4 4 8 12 NA 20 ", header=TRUE) df2 <-df1*2 df1 df2 df3 <-sapply(names(df1),function(x) {df1[[x]]<- df2[[x]]}) df1 df3 [[alternative HTML version deleted]]
2010 Feb 10
2
sum sections of data of different lengths from within a data frame
Dear R Help: I am trying to sum data from one column in a dataframe based on a value in another. I do not know how to do this easily in R. For example: Col A Col B 1 0 3 0 2 1 2 0 1 0 4 0 1 1 9 1 3 0 5 0 2 1 I would like to cumsum the values in Col A for all rows where Col B is 0, and a value of 1 in Col B will reset
2011 May 28
1
newbie xml parsing question
I am trying to read some data off the zillow site. Newbie to xml, html, parsing and the xml package. I've been able to load the web page I'm interested with the following code but I'm not sure of the next step to get the information I'm interested in into R : library(XML) url <- "http://www.zillow.com/homes/511 W Lafayette St, Norristown, PA_rb" doc <-doc <-
2013 Jan 04
2
"By" function Frame Conversion (with Multiple Indices)
Hello, I have the following dataset. Please note that there are missing values on records 4 and 5: id,age,weight,height,gender 1,22,180,72,m 2,13,100,67,f 3,5,40,40,f 4,6,42,,f 5,12,98,66, 6,50,255,60,m I'm using the "By" function like this: list1 <- by(dataset[c("weight", "height")], dataset[c("age", "gender")],
2012 Oct 26
3
regression analysis in R
Dear useRs, i have vectors of about 27 descriptors, each having 703 elements. what i want to do is the following 1. i want to do regression analysis of these 27 vectors individually, against a dependent vector, say B, having same number of elements.2. i would like to know best 10 regression results, if i do regression analysis of dependent vector against the random combination of any 4
2013 May 26
0
SAPPLY function for COLUMN NULL
colnames(dd) #[1] "col1" "colb" null_vector<- colnames(dd) sapply(null_vector,makeNull,dd) #???? col1 colb #[1,]?? NA??? 4 #[2,]??? 2?? NA #[3,]??? 3??? 2 #[4,]??? 4?? NA #[5,]??? 1??? 4 #[6,]?? NA??? 5 #[7,]??? 1??? 6 A.K. >I am trying to make a column value in a dataframe = NA if there is a 0 or high value in that column. I need to do this process repeatedly, hence
2005 Aug 22
3
read a table ignoring specific rows ?
Dear R users, First of all sorry for this question, surely quite naive. (I searched on the R site but was unable to find by myself). I have a table, called infile : 1 2 3 4 5 6 7 8 9 I would like to read it and ignore the rows with 1st element > 3 I do it now with a for loop, and it's ok, but I was expecting something simpler, like : intable = read.table(infile); newtable =
2012 Jul 14
2
Arrange two columns into a five variable dataframe
Hi, I hope that folks can give me some simple approaches to taking the data set below, which is accumulated in two columns called "long" and "group", then arrange the data is the "long" column into a data frame containing five variables: "Group 1", "Group 2", "Group 3", "Group 4", and "Group 5". I am hoping for a few
2015 Feb 24
2
intercalar elementos de vectores
Gracias, Carlos. Habia pensado en algo similar usando sapply(): sapply(seq(1, ncol(vtmp), by = 2), function(i) c(rbind(as.character(vtmp[, i]), as.character(vtmp[, i+1])))) Dependiendo de la dimension de los datos, quizas mapply() sea mas eficiente que sapply(). Saludos cordiales, Jorge.- 2015-02-25 1:01 GMT+11:00 Carlos Ortega <cof en qualityexcellence.es>: > Hola, > > Este