Displaying 20 results from an estimated 4000 matches similar to: "Adding a new conditional column to a list of dataframes"
2018 Apr 15
0
Adding a new conditional column to a list of dataframes
> On Apr 15, 2018, at 4:08 AM, Allaisone 1 <Allaisone1 at hotmail.com> wrote:
>
>
> Hi all ..,
>
>
> I have a list of 7000 dataframes with similar column headers and I wanted to add a new column to each dataframe based on a certain condition which is the same for all dataframes.
>
>
> When I extract one dataframe and apply my code it works very well as
2018 Feb 25
4
reshaping column items into rows per unique ID
Hi All
I have a datafram which looks like this :
CustomerID DietType
1 a
1 c
1 b
2 f
2 a
3 j
4 c
4 c
4 f
And I would like to reshape this so I can
2018 Feb 25
0
reshaping column items into rows per unique ID
Hi Allaisone,
If you want a data frame as the output you will have to put up with a
few NA values unless each Customer has the same number of diet types:
a1df<-read.table(text="CustomerID DietType
1 a
1 c
1 b
2 f
2 a
3 j
4
2018 Feb 25
0
reshaping column items into rows per unique ID
I believe you need to spend time with an R tutorial or two: a data frame
(presumably the "table" data structure you describe) can *not* contain
"blanks" -- all columns must be the same length, which means NA's are
filled in as needed.
Also, 8e^5 * 7e^4 = 5.6e^10, which almost certainly will not fit into any
local version of R (maybe it would in some server version --
2013 Feb 12
3
grabbing from elements of a list without a loop
Hello!
# I have a list with several data frames:
mylist<-list(data.frame(a=1:2,b=2:3),
data.frame(a=3:4,b=5:6),data.frame(a=7:8,b=9:10))
(mylist)
# I want to grab only one specific column from each list element
neededcolumns<-c(1,2,0) # number of the column I need from each element of
the list
# Below, I am doing it using a loop:
newlist<-NULL
for(i in 1:length(mylist) ) {
2004 Aug 01
2
Strange Problem with "proj" and "aov" for split-plot analysis output
I'm using R 1.8.1 on Red Hat Linux 9. I've worked out the linear model
decomposition by hand. Using "aov" with "Error" to fit a split-plot
model, I get very different results depending on whether I use the
"data" argument for "aov" or not. When I use the "data" argument, the
ANOVA table from "summary" is correct but the
2010 Jun 28
2
ask a question about list in R project
my list al is as below:
mylist=list(c(2,3),5,7)
> mylist
[[1]]
[1] 2 3
[[2]]
[1] 5
[[3]]
[1] 7
How could I get the following FOUR lists:
First one
[[1]]
[1] 3
[[2]]
[1] 5
[[3]]
[1] 7
Second one
[[1]]
[1] 2
[[2]]
[1] 5
[[3]]
[1] 7
Third One
[[1]]
[1] 2 3
[[2]]
[1] 7
Last one
[[1]]
[1] 2 3
[[2]]
[1] 5
Do I have to use 'for' loops? Please give me sone suggestions!
Thank you
2004 Sep 12
2
boxplot() from list
I have a list containing 48 objects (each with 30 rows and 4 columns, all
numeric), and wish to produce 4 boxplot series (with 48 plots in each) ,
one for each column of each object.
Basically I want a boxplot from boxplot(mylist[[]][,i])
for i in 1:4. It seems that I can create a boxplot of length 48 from the
entire list, but I don't seem able to subscript to return 4 boxplots from
the list
2004 Nov 01
5
make apply() return a list
Hi,
I have a dataframe (say myData) and want to get a list (say myList) that
contains a matrix for each row of the dataframe myData. These matrices are
calculated based on the corresponding row of myData. Using a for()-loop to do
this is very slow. Thus, I tried to use apply(). However, afaik apply() does
only return a list if the matrices have different dimensions, while my
matrices have
2010 May 17
1
suggestions/improvements for recoding strategy
I am recoding some data. Many values that should be 1.5 are recorded
as 1-2. Some example data and my solution is below. I am curious about
better approaches or any other suggestions. Thanks!
# example input data
myData <- read.table(textConnection("id, v1, v2, v3
a,1,2,3
b,1-2,,3-4
c,,3,4"),header=TRUE,sep=",")
closeAllConnections()
# the first column is IDs so remove
2018 Apr 17
2
Time intervals in a datframe
Hi all
I have a list of multiple datframes with the same column headers. The last column in each datframe contains a vector of "Interval" class after I have produced this column using "lubridate" package. I needed to convert my list of dataframes to be in a single dataframe for further analysis. I did this using the following syntax :
SingleDataframe <- ldply
2018 Apr 17
0
Time intervals in a datframe
> On Apr 17, 2018, at 10:10 AM, Allaisone 1 <allaisone1 at hotmail.com> wrote:
>
>
> Hi all
>
> I have a list of multiple datframes with the same column headers. The last column in each datframe contains a vector of "Interval" class after I have produced this column using "lubridate" package. I needed to convert my list of dataframes to be in a single
2009 May 26
1
Bug in "$<-.data.frame" yields corrupt data frame (PR#13724)
Full_Name: Steven McKinney
Version: 2.9.0
OS: Mac OS X 10.5.6
Submission from: (NULL) (142.103.207.10)
A corrupt data frame can be constructed as follows:
foo <- matrix(1:12, nrow = 3)
bar <- data.frame(foo)
bar$NewCol <- foo[foo[, 1] == 4, 4]
bar
lapply(bar, length)
> foo <- matrix(1:12, nrow = 3)
> bar <- data.frame(foo)
> bar$NewCol <- foo[foo[, 1] == 4, 4]
2005 Nov 29
1
Indexing variables within lapply?
Hello
I am using R 2.2.0 with Windows XP.
I've got a five element list object, each element containing two
dataframes of equivalent size.
> str(mylist)
List of 1
$ data1:List of 2
..$ data1a :`data.frame': 77 obs. of 63 variables:
.. ..$ var1 : num [1:77] 0.41375 0.00056 1.43040 1.43528 0.61730 ...
.. ..$ var2 : num [1:77] 1.154 1.686 0.673 0.800 0.760 ...
..
2006 Oct 17
2
Question about managing searching path
Hi all,
I'm having sometrouble with managing the seach path, in a function , I need to attach some data set at the begining
and detach them at the end, say, myfunction<- function() { attach(mylist); ............. detach(mylist) } ,
the problem is, since I am still debugging this code, sometimes it got error and ended before reaching the end, thus
the data is left in the
2018 Feb 25
1
reshaping column items into rows per unique ID
Hi Allaisone,
I took a slightly different approach but you might find this either as or
more useful than your approach, or at least a start on the path to a
solution you need.
df1 <-
data.frame(CustId=c(1,1,1,2,3,3,4,4,4),DietType=c("a","c","b","f","a","j","c","c","f"),
2009 Apr 29
1
Corrupt data frame construction - bug?
Hi useRs,
A recent coding infelicity along these lines
yielded a corrupt data frame.
foo <- matrix(1:12, nrow = 3)
bar <- data.frame(foo)
bar$NewCol <- foo[foo[, 1] == 4, 4]
bar
lapply(bar, length)
> foo <- matrix(1:12, nrow = 3)
> bar <- data.frame(foo)
> bar$NewCol <- foo[foo[, 1] == 4, 4]
> bar
X1 X2 X3 X4 NewCol
1 1 4 7 10 <NA>
2 2 5 8 11
2012 Oct 10
3
How to replicate SAS by group processing in R
Hello,
I am trying to re-code all my programs from SAS into R.
In SAS I use the following code:
proc sort data=upper;
by tdate stock_symbol expire strike;
run;
data upper1;
set upper;
by tdate stock_symbol expire strike;
if first.expire then output;
rename strike=astrike;
run;
on the following data set:
tdate stock_symbol expiration strike
9/11/2012 C 9/16/2012
2012 Oct 19
4
Creating a new by variable in a dataframe
Hello,
I have a dataframe w/ 3 variables of interest: transaction,date(tdate) &
time(event_tim).
How could I create a 4th variable (last_trans) that would flag the last
transaction of the day for each day?
In SAS I use:
proc sort data=all6;
by tdate event_tim;
run;
/*Create last transaction flag per day*/
data all6;
set all6;
by tdate event_tim;
last_trans=last.tdate;
Thanks
2017 Nov 18
3
Complicated analysis for huge databases
The loop :
AllMAFs <- list()
for (i in length(SeparatedGroupsofmealsCombs) {
AllMAFs[[i]] <- apply( SeparatedGroupsofmealsCombs[[i]], 2, function(x)maf( tabulate( x+1) ))
}
gives these errors (I tried this many times and I'm sure I copied it entirely) :-
Error in apply(SeparatedGroupsofmealsCombs[[i]], 2, function(x) maf(tabulate(x + :
object 'i' not found
> }