similar to: How to write a list object's name to a new dataframe in that list object

Dear R community, I have two dataframes "first" and "second" which share a unique identifier. I wish to make a new dataframe "third" retaining only the rows in "first" which also occur in "second". I have tried using merge but can't seem to figure it out. Any ideas? Thanks! Mark

Hello R-helpers, I have 10 dataframes (named data1, data2, ... data10) and I would like to add 5 new columns to each dataframe using the following code: data1$LogDepth<-log10(data1[,2]/data1[,4]) data1$LogArea<-log10(data1[,3]/data1[,5]) data1$p<-2*data1[,6]/data1[,7] data1$Exp<-data1[,2]^(2/data1[,8]) data1$s<-data1[,3]/data1[,9] ...but I would prefer not to repeat this chunk of

Dear R-helpers, I have a list containing 5000 elements, each element is a dataframe containing one ID column (identical over the 5000 dataframes) and 9 numeric variables, e.g. ID VAR1 VAR2 VAR3 ... VAR9 I would like to create a new dataframe containing the ID column and the mean values of the 9 numeric variables. So, the structure of this new dataframe would be identical to the structure of the

I would like to export a dataframe to a .csv using: >write.csv(dataframe,"dataframe.csv") but I need to add four "header" lines to the csv that are not part of the dataframe (which itself has a line of column headers). The difficulty (for me, at least!) lies in the requirement that certain elements of the header (X, Y and the number of "Q"s - please see example

Hi, I am helping another R user (off list) and I would like to email her an R script containing the data she needs and the code to solve her problem. I have made a small dummy dataset, but instead of sending her a CSV I would prefer to send the data embedded in the script, so there would be a like in the script like: my.df<-c( etc, etc, etc I have made the dataframe (in a spreadsheet) and

Given the following dataframe: A=1:10 B=(a-5)^2 DATAFRAME=data.frame(A,B) How can I sort DATAFRAME increasing (or decreasing, for that matter) by B without making reference to A, or any other column? I've read ?order and ?sort but cannot seem to figure this out. Thank you. Mark

Hi R-helpers, I have a dataframe with 60columns and I would like to convert several columns to factor, others to numeric, and yet others to dates. Rather than having 60 lines like this: data$Var1<-as.factor(data$Var1) I wonder if it's possible to write one line of code (per data type, e.g. factor) that would apply a function (e.g., as.factor) to several (non-contiguous) columns. So, I

Hi R-helpers, I have a dataframe (called data) with 100 columns, the columns of which are named with integers ranging from 1900 to 1999. I wish to extract those columns which names are >=1950 and <=1970. I tried: data2<-subset(data,select=(names(data)>=1950 & names(data)<=1970)) but that doesn't work. Any ideas? Thanks! Mark [[alternative HTML version deleted]]

Hi everyone, I've got a question concerning the function Box.test for testing autocorrelation in my data. My data consist of (daily) returns of several stocks over time (first row=time, all other rows=stock returns). I intend to perform a Box-Ljung test for my returns (for each stock). Since I have about 3000 stocks in my list, I'm not able to perform the test individually for each

Hello, I have two dataframes DF1 and DF2 that should be identical but are not (DF1 has some rows that aren't in DF2, and vice versa). I would like to produce a new dataframe DF3 containing rows in DF1 that aren't in DF2 (and similarly DF4 would contain rows in DF2 that aren't in DF1). I have a solution for this problem (see self contained example below) but it's awkward and

Hi All, I need to place lists or vectors within dataframes as single elements. However when I try this: df=data.frame(y=1, x=I(list(c("a","b"), c("f","c"), c("a")))) df df[1,'x']=I(c("a","d")) I get this error, even though I am using I(): Error in `[<-.data.frame`(`*tmp*`, 1, "x", value =

Hello R-helpers, I have run the following line of code: x<-dat$col and now I would like to assign names(x) to be "dat$col" (e.g., a character string equal to the column name that I assigned to x). What I am trying to do is to assign columns in my dataframe to new objects called x and y. Then I will use x and y within a new function to make plots with informative axis labels (e.g.,

Dear R-helpers, I have split a dataframe into a list with five elements, with the following code: > datalist<-split(data,data$UNIT) I would now like to run some code (below) on each element of the list to extract rows from the list elements; then I would like to rbind the extracted rows into a new dataframe containing all of the extracted rows from all of the list elements. I don't

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Hello, I would like to be able to update an existing column in a dataframe, like this... data$score[data$type=="1" & data$year=="2001"]<-data$score * 0.111 data$score[data$type=="1" & data$year=="2002"]<-data$score * 0.222 data$score[data$type=="1" & data$year=="2003"]<-data$score * 0.333 ...but, if possible,

Dear R-helpers, I have a dataframe called "trackpoints" with several columns including a column called "time", eg: > trackpoints ?? ? ? ?time 1 ? 12:00:00 2 ? 12:00:01 3 ? 12:00:02 . . . 298 12:04:57 299 12:04:58 300 12:04:59 I also have a dataframe called "data" that contains columns called "ID", "start" and "stop", eg: > data

I'm trying to sort a DATAFRAME by a column "ID" that contains alphanumeric data. Specifically,"ID" contains integers all preceeded by the character "g" as in: g1, g6, g3, g19, g100, g2, g39 I am using the following code: DATAFRAME=DATAFRAME[order(DATAFRAME1$ID),] and was hoping it would sort the dataframe by ID in the following manner g1, g2, g3, g6, g19,

Dear all I want to generate a list like this: a <- data.frame(1:10) attr(a,'myattribute') <- 'something' b <- data.frame(11:20) attr(b,'myattribute') <- 'anything' mylist <- list(a,b) Is there a way to place the dataframes into the list giving them the attribute at the same time? I don't want to create all the dataframes in my workspace first.

Dear R-helpers, I have two rows in my dataframe: ID VALUE 1A 10 1B 15 and I would like to combine these two rows into a single (new) row in my dataframe: ID VALUE 1 25 ...simply by specifying a new value for ID and summing the two VALUES. I have been trying to do this with with rbind, but it's not working. I'd appreciate any pointers. Thanks, Mark Na [[alternative

Folks, I have three dataframes storing some information about two currency pairs, as follows: R> a EUR-USD NOK-SEK 1.23 1.33 1.22 1.43 1.26 1.42 1.24 1.50 1.21 1.36 1.26 1.60 1.29 1.44 1.25 1.36 1.27 1.39 1.23 1.48 1.22 1.26 1.24 1.29 1.27 1.57 1.21 1.55 1.23 1.35 1.25 1.41 1.25 1.30 1.23 1.11 1.28 1.37 1.27 1.23 R> b EUR-USD NOK-SEK 1.23 1.22 1.21 1.36 1.28 1.61 1.23 1.34 1.21 1.22