similar to: How to drop variables using a wildcard and logic...

I have a dataframe called "data" with 5 records (in rows) each of which has been scored on each of many variables (in columns). Five of the variables are named var1, var2, var3, var4, var5 using headers. The other variables are named using other conventions. I can create a new variable called var6 with the value 15 for each record with this code: > var6=var1+var2+var3+var4+var5

Hi R-helpers, I wish to produce frequency histograms of all of the variables in my dataframe (except some identifying variables). I have tried >hist(dataframe[,3:20]) to produce histograms of the 3rd through 20th variables in my dataframe, but R doesn't like that. Could anyone provide a suggestion? Also, once I produce the histograms, I'd like to save them as graphic files on my

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

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,

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 (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]]

Hello, My dataframe has new columns that start with the number 1 or 2 (resulting from a reshape cast command). Instead of having these columns automatically renamed by R so start with the letter X, I would like to rename these columns to start with the characters "SURV_" (e.g., SURV_1, SURV_2). I can't seen to use grep() to identify and rename the columns starting with either 1 or

Hi R-helpers, I have imported data from Excel using the following code: library(xlsReadWrite) data <- read.xls(data,colClasses=c("character")) and this results in all of the empty (blank) cells in the imported Excel file also being empty (blank) in the resulting dataframe. I am not used to having blanks (rather NAs) and I think these are caused by the colClasses argument. I would

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

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

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

Hello all, I have what I think is a simple question but I've been unable to solve it. I have the following string: A[&states=1]:[&rate=2]425, B[&states=3]:[&rate=5]500 I would like to combine the two expressions in the [], so that only one set of [] is present after each letter, so that I have the following string: A:[&states=1,&rate=2]425,

Hi R-helpers, I'm trying to use this code > pvh_dnv<-pvh[sapply(pvh=="dnv"),] to make a new dataframe containing the rows from pvh that contain the value of "dnv" in ANY column. But, it's not working. I get this error Error in match.fun(FUN) : element 1 is empty; the part of the args list of 'is.function' being evaluated was: (FUN) which, to

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

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.,

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

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

Dear R-helpers, I know how to use unique to select unique rows, e.g. unique.rows<-unique(dataframe) but I would like to select those rows that are unique only only TWO of my dataframe's columns (so, two rows with the same value on these two columns would not be kept, even if they had different values in other columns). For example, I have a dataframe with 10 columns, two of which are

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

Hello R-helpers, I have a list that only contains dataframes. Each element of the list (i.e., each dataframe) has a unique name ("one" through "ten"). I wish to add a new column (called "NAME") to each list element (i.e each datarame) and I want that column to contain the name of it's list element. e.g. the list element (i.e., dataframe) called "one"