similar to: how to best add columns to a matrix with many columns

Displaying 20 results from an estimated 10000 matches similar to: "how to best add columns to a matrix with many columns"

2012 Sep 02
2
a newbie seeking for a simple problem
Dear Experienced R users, I have a looks-like simple but complicated problem urgently needed to be solved. Below is the detail: I have two dataframes, df1, df2. df1 contains two column and many thousands rows: column 1 is a "gene_name", column 2 is "value". df2 contains only one column which is "gene_name" with couple hundred rows. I want to change "value"
2010 Sep 14
3
how to compute when row length is different
hi guys..please help me with this i am working on two data frames one goes like this: DF1 Sample_id RepairHours Denatured Dose ZeroMean FourtyFiveMean NinetyMean 1 SDM071 0 1 B 60.5 19.0 45.0 2 SDM071 1 1 B 46.0 23.0 42.5 3 SDM071 2 1 B 52.5 24.0 40.0 4 SDM071
2012 Nov 15
4
using ifelse to remove NA's from specific columns of a data frame containing strings and numbers
Hi everyone, I have a data frame one of whose columns is a character vector and the rest are numeric, and in debugging a script, I noticed that an ifelse call seems to be coercing the character column to a numeric column, and producing unintended values as a result. Roughly, here's what I tried to do: df: a data frame with, say, the first column as a character column and the second and
2008 Dec 28
2
Conditional operation on multiple columns from two data frames
Hi- I have two data frames for which I wish to conditionally subtract the values of one dataframe from the other. I want to subtract df1$x from df2$x when their id is equal and the absolute value of difference between the dates is 12 hours or less. If there is no match of equal id's and dates less than 12 hours apart I want it to return "NA". Note that df1 has missing values in x
2011 Nov 30
1
Replace columns in a data.frame randomly splitted
Dear community, I'm working with the data.frame attached ( http://r.789695.n4.nabble.com/file/n4122926/df1.xls df1.xls ), let's call it df1. I typed: df1<- read.xls("C:/... dir .../df1.xls",colNames= TRUE, rowNames= TRUE) Then I splited randomly df1 using splitdf function (http://gettinggeneticsdone.blogspot.com/2011/03/splitting- dataset-revisited-keeping.html)
2018 Jan 08
2
Replace NAs in split lists
Thank you Jeff. Your code works, as usual , perfectly. I am just wondering why if i put the whole code in one line, i get an error message. sdf2 <- lapply( sdf, function(z){z$Value <-ifelse(is.na(z$Value),z$Value[!is.na(z$Value)][1],z$Value)z}) error. unexpected symbol in sdf2 Thanks again EK On Mon, Jan 8, 2018 at 3:12 AM, Jeff Newmiller <jdnewmil at dcn.davis.ca.us> wrote: >
2011 Nov 23
2
Is there an easier way to iterate over multiple data frames in R?
> for (d in paste('df', 1:3, sep='')) { + assign(d, as.data.frame(replicate(3, rnorm(4)))) + } > dats = list(df1,df2,df3) > for (i in 1:length(dats)) { + names(dats[[i]]) = c('w', 'l', 'h') + } > dats [[1]] w l h 1 1.24319239 -0.05543649 0.05409178 2 0.05124331 -1.89346950 0.33896273 3 -1.69686777 -0.35963008
2011 Aug 18
2
Best way/practice to create a new data frame from two given ones with last column computed from the two data frames?
Dear expeRts, What is the best approach to create a third data frame from two given ones, when the new/third data frame has last column computed from the last columns of the two given data frames? ## Okay, sounds complicated, so here is an example. Assume we have the two data frames: df1 <- data.frame(Year=rep(2001:2010, each=2), Group=c("Group 1","Group 2"), Value=1:20)
2018 Jan 08
0
Replace NAs in split lists
Upon closer examination I see that you are not using the split version of df1 as I usually would, so here is a reproducible example: #---- df1 <- read.table( text= "ID ID_2 Firist Value 1 a aa TRUE 2 2 a ab FALSE NA 3 a ac FALSE NA 4 b aa TRUE 5 5 b ab FALSE NA ", header=TRUE, as.is=TRUE ) sdf <- split( df1, df1$ID ) # note the extra [ 1 ]
2018 Jan 08
0
Replace NAs in split lists
I don't know. You seem to be posting in HTML so your code is mangled. Can you post plain text and use the reprex package to make sure it produces the errorin a clean R session? -- Sent from my phone. Please excuse my brevity. On January 8, 2018 8:03:45 AM PST, Ek Esawi <esawiek at gmail.com> wrote: >Thank you Jeff. Your code works, as usual , perfectly. I am just >wondering why
2011 Jun 06
1
Merge two columns of a data frame
I have the following data: prefix <- c("cheap", "budget") roots <- c("car insurance", "auto insurance") suffix <- c("quote", "quotes") prefix2 <- c("cheap", "budget") roots2 <- c("car insurance", "auto insurance") roots3 <- c("car insurance", "auto
2018 Jan 08
1
Replace NAs in split lists
OPS! Sorry i did indeed posted the code in HTML; should have known better. ifelse(is.na(z$Value),z$Value[!is.na(z$Value)][1],z$Value)z}) error. unexpected symbol in sdf2 On Mon, Jan 8, 2018 at 11:44 AM, Jeff Newmiller <jdnewmil at dcn.davis.ca.us> wrote: > I don't know. You seem to be posting in HTML so your code is mangled. Can you post plain text and use the reprex package to
2013 Feb 26
2
merging or joining 2 dataframes: merge, rbind.fill, etc.?
#I want to "merge" or "join" 2 dataframes (df1 & df2) into a 3rd (mydf). I want the 3rd dataframe to contain 1 row for each row in df1 & df2, and all the columns in both df1 & df2. The solution should "work" even if the 2 dataframes are identical, and even if the 2 dataframes do not have the same column names. The rbind.fill function seems to work. For
2013 Jan 15
1
SQLDF column errors
I am trying to exclude integer values from a small data frame 1, d1 that have matching hits in data frame 2, d2 (Very big) which involves matching those hits first. I am trying to use sqldf on the df's in the following fashion: df1: V1 12675 14753 16222 18765 df2: head(df2) V1 V2 13647 rd1500 14753 rd1580 15987 rd1590 16222 rd2020.....
2011 Aug 18
2
Selecting subset of factor levels
Dear r-help, I would like to select a subset of levels from a factor variable in a data frame and return a data frame. The data set consists of 3 variables, 2 of which are factors (Site, Fish) and one numeric (Datavalue) as follows: Site Fish Datavalue AB 2-1 2.3 AB 2-1 2.4 AB 2-1 2.2 AB 2-2 2.6 AB 2-2 2.5 AB 2-2 2.7 AB 2-3
2012 Jun 03
2
merging single column from different dataframe
Hi all, probably really simple to solve, but having no background in programming I haven't been able to figure this out: I have two dataframes like df1 <- data.frame(names1=c('aa','ab', 'ac', 'ad'), var1=c(1,5,7,12)) df2 <- data.frame(names2=c('aa', 'ab', 'ac', 'ad', 'ae'), var2=c(3,6,9,12,15)) Now I want merge
2012 Oct 11
1
as.data.frame.matrix() returns an invalid object
Hi, Two ways to create what should normally be the same data frame: > df1 <- data.frame(a=character(0), b=character(0))> df1 [1] a b <0 rows> (or 0-length row.names) > df2 <- as.data.frame(matrix(character(0), ncol=2, dimnames=list(NULL, letters[1:2]))) > df2 [1] a b <0 rows> (or 0-length row.names) unique() works as expected except that I
2018 Jan 08
2
Replace NAs in split lists
Hi With the example, na.locf seems to be the easiest way. > library(zoo) > na.locf(df1) ID ID_2 Firist Value 1 a aa TRUE 2 2 a ab FALSE 2 3 a ac FALSE 2 4 b aa TRUE 5 5 b ab FALSE 5 Cheers Petr > -----Original Message----- > From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Jeff > Newmiller > Sent: Monday, January
2013 Jan 02
2
rbind: inconsistent behaviour with empty data frames?
The rbind on empty and nonempty data frames behaves inconsistently. I am not sure if by design. In the first example, first row is deleted, which may or may not be on purpose: df1 <- data.frame() df2 <- data.frame(foo=c(1, 2), bar=c("a", "b")) rbind(df1, df2) foo bar 2 2 b Now if we continue: df1 <- data.frame(matrix(0, 0, 2)) names(df1) <- names(df2)
2009 Jan 21
3
merging several dataframes from a list
Hi there, I have a list of dataframes (generated by reading multiple files) and all dataframes are comparable in dimension and column names. They also have a common column, which, I'd like to use for merging. To give a simple example of what I have: df1 <- data.frame(c(LETTERS[1:5]), c(2,6,3,1,9)) names(df1) <- c("pos", "data") df3 <- df2 <- df1 df2$data