Displaying 20 results from an estimated 10000 matches similar to: "merging several dataframes from a list"
2009 Oct 07
1
merging dataframes with an unequal number of variables
Hallo Everyone
I have the kind of problem that one should never have because one must
always plan well and communicate with your team. But now I haven't so here
is my problem.
I have data coming in on a daily basis from surveys in 10 towns. The
questionnaire has 62 variables but some of the regions have used older
versions of the questionnaire that have a few variables less. I want to
combine
2008 Feb 19
2
Looping through a list of objects & do something...
Hey Folks,
Could somebody show me how to loop through a list of dataframes? I want to
be able to generically access their elements and do something with them.
For instance, instead of this:
df1<- data.frame(x=(1:5),y=(1:5));
df2<- data.frame(x=(1:5),y=(1:5));
df3<- data.frame(x=(1:5),y=(1:5));
plot(df1$x,df1$y);
plot(df2$x,df2$y);
plot(df3$x,df3$y);
I would like to do something like:
2010 Dec 16
2
Compare two dataframes
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
2009 Feb 27
1
levelplot help needed
Hi there,
I'm looking for someone who can give me some hints how to make a nice
levelplot. As an example, I have the following code:
# create some example data
# --------------------------------------
xl <- 4
yl <- 10
my.data <- sapply(1:xl, FUN = function(x) { rnorm( yl, mean = x) })
x_label <- rep(c("X Label 1", "X Label 2", "X Label 3", "X
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)
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
2011 Aug 29
2
splitting into multiple dataframes and then create a loop to work
Dear All
Sorry for this simple question, I could not solve it by spending days.
My data looks like this:
# data
set.seed(1234)
clvar <- c( rep(1, 10), rep(2, 10), rep(3, 10), rep(4, 10)) # I have 100
level for this factor var;
yvar <- rnorm(40, 10,6);
var1 <- rnorm(40, 10,4); var2 <- rnorm(40, 10,4); var3 <- rnorm(40, 5, 2);
var4 <- rnorm(40, 10, 3); var5 <- rnorm(40, 15,
2010 Sep 04
4
Please explain "do.call" in this context, or critique to "stack this list faster"
I've been doing some consulting with students who seem to come to R
from SAS. They are usually pre-occupied with do loops and it is tough
to persuade them to trust R lists rather than keeping 100s of named
matrices floating around.
Often it happens that there is a list with lots of matrices or data
frames in it and we need to "stack those together". I thought it
would be a simple
2010 Jan 22
2
Question on Merge/Lookup
I need to merge three datasets and don't know how. If I were using SQL, I
would use df3, look up the characteristics of each date in df1 and the value
for each observation in df2.
df1 - unique list of Dates and characteristics of those dates
Date, YYYYMM, YYYYWW, DOW
df2 - the raw data
Date, Place, Value
df3 - all posibile combinations of Date + Place (via
2008 Mar 03
3
looping through data frames in a workspace
All,
I have a workspace containing only data frame objects. I would like to
loop though each one and clean-up text columns in them. How can I have
R loop through the list? I have tried to find an answer in R help but
the closest solution I can find is to make a static list of data
frames, as illustrated in this recent post:
---------begin post
On Tuesday 19 February 2008 (19:51:15), TLowe wrote:
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]]
2011 Apr 30
3
indexing into a data.frame using another data.frame that also contains values for replacement
Hello all,
I have a quandry I have been scratching my head about for a
while. I've searched the manual and the web and have not been able to
find an acceptable result, so I am hoping for some help.
I have two data frames and I want to index into the first using
the second, and replace the specific values I have indexed with more
values from the second data.frame. I can do this
2003 Sep 04
1
error in lm.fit
Hello R user,
I have several data frames with >100 columns and I did a linear regression
over time of each column
df1.lm <- lapply(df1, function(x) lm(x~year)$coeff[2])
that worked fine and I get slope of each column oder time - until I divided
df1 by df2
df3 <- df1/df2
> df3.lm <- lapply(df3, function(x) lm(x~year)$coeff[2])
Error in lm.fit(x, y, offset = offset, ...) :
2011 Mar 18
1
Problem with Slope.test function
Hi all,
I need to test the significnce of difference between slopes of two regression lines and regression line with theoretical line. I try to use Slope.test function from emu package,
but an error occured...
library(emu)
d1<-data.frame(P1=c(1,2,3,5,7,8,9,13,14,15),
P2=c(1,2,5,8,11,13,15,15,18,24),
R=c(2,7,8,9,16,21,27,31,33,36)) # First data set
m1<-lm(R~P1+P2+P1*P2,data=d1) # Regr.
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
2004 Mar 09
5
Adding data.frames together
I have a series of data frames that are identical structurally, i.e. -
made with the same code, but I need to add them together so that they
become one, longer, data frame, i.e. - each of the slot vectors are
increased in length by the length of the added data frame vectors.
So if I have df1 with a slot A so that length(df1$A) = 100 and I have
df2 with a slot A so that length(df2$A)=200 then I
2005 Oct 20
1
Windows 2000 crash while using rbind (PR#8225)
Windows 2000 reports that "Rgui.exe has generated errors and will be =
closed by Windows. You will need to restart the program." when using =
rbind.=20
df1 <- data.frame(cbind(x=3D1, y=3D1:1000), fac=3Dsample(LETTERS[1:3], =
1000, repl=3DTRUE))
df2 <- data.frame(cbind(x=3D1, y=3D1:10), fac=3Dsample(LETTERS[4:6], =
10, repl=3DTRUE))
df3 <- data.frame(cbind(x=3D1,
2013 Apr 02
2
Create a vector without using an external 'if statement'
Dear R-users,
suppose I have three dataframes like these
df1:
mydate min_temp
31032013 12
01042013 8
02042013 -999
df2:
mydate min_temp
31032013 10
01042013 11
02042013 14
df3:
mydate min_temp
31032013 4
01042013 3
02042013 5
where -999 means that the temperature data is not available (at the moment I cannot change it to NA because I am not the db administrator);
suppose also that oggi is
2006 Aug 13
2
How to order or sort a data.frame
I have a dataframe where I would like to order first
by variable, year, and then within that variable by
month.
So far the only way that I have seen to do this is to
order by year and then subset year and sort by month
and then do an rbind to get things back together.
Is this the right approach?
Example:
us.state <-rep("California", 23)
2009 Feb 19
3
Multiple merge, better solution?
Hello,
My problem is that I would like to merge multiple files with a common
column but merge accepts only two
data.frames to merge. In the real situation, I have 26 different
data.frames with a common column. I can of course use merge many times
(see below) but what would be more sophisticated solution? For loop?
Any ideas?
DF1 <- data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 <-