Displaying 20 results from an estimated 1300 matches similar to: "Applying a function to a column of a data frame"
2012 Jun 10
3
Data.frames can not hold objects...What can be done in the following scenario?
R-Help community,
I understand that data.frames can hold elements of type double, string
etc but NOT objects (such as a matrix etc). This is not convenient for
me in the following situation. I have a function that takes 2 inputs
and returns a vector:
testfun <- function (x,y) seq(x,y,1)
I have a data.frame defined as follows:
testframe<-data.frame(xvalues=c(2,3),yvalues=c(4,5))
I would
2011 May 23
1
Applying boxplot.stats to multiple value lists
Hello all R gurus,
I have a following problem which I hope someone will help me to solve.
I have a data.frame in form similar to below. > testframe<-data.frame("Name"=c("aa","aa","aa","aa","aa","bb","bb","bb","bb","bb"),"Value"=c(1,100,1,1,1,100,100,100,100,1))
2012 Jul 02
2
Constructing a list using a function...
Hi All
I have a dataframe:
myframe<-data.frame(ID=c("first","second"),x=c(1,2),y=c(3,4))
And I have a function myfun:
myfun<-function(x,y) x+y
I would like to write a function myfun2 that takes myframe and myfun
as parameters and returns a list as below:
mylist
$first
[1] 4
$second
[2] 6
Could you please help me with this? Doesn't seem like the
2005 Mar 29
2
strange error with rw2010dev
With rw2010dev I get a strange protect(): protection stack overflow
error with a small data frame which otherwise is usable:
If anybody wants to have a look I can provide an RData file
with the problematic data frame.
Doesn't seem to be necessary, the following simulated example
generates the error:
> testmat <- matrix(1:80, 20,4)
> dim(testmat)
[1] 20 4
> str(testmat)
int
2009 Jun 20
2
Special characters in Rd example section will cause errors
Hi (Duncan?),
The other day I noticed some characters will cause errors in R CMD
CHECK because of parse_Rd(), and AFAIK, these chars include '%', '{'
and '}'. For example, note the comments in the example section:
%~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~%
\name{testfun}
\Rdversion{1.1}
\alias{testfun}
\title{
A Test
}
\description{
A test
}
\usage{
testfun()
}
\value{
NULL
}
2011 Jul 12
2
foreach not recognizing functions in memory
All,
I am not understanding the scoping used in foreach when it is used
inside a function. I keep getting "could not find function" errors for
functions that are in memory when I try to use foreach within a function
call. I have a simple example below. "testFun" is in memory and works
when called by foreach directly, but when I place foreach in a function
called
2012 Oct 07
3
get: problem with environments
Dear R users,
I am running R-2.15.1 in Linux Slackware64-14.0. Here is my minimal working example:
testfun <- function (x) {
a <- 0;
sapply(X="a", FUN=get, envir=sys.frame(which=x));
}
Inside R, that is R called from within a Linux terminal, the following code works:
testfun(x=5)
print(testfun(x=6))
But within rkward the above code fails and the following works:
testfun(x=1)
2012 Aug 08
1
random number generator with SNOW/ Parallel/ foreach
Dear All,
I have three classes of questions about generating random numbers with
different packages (windows xp 32bit R).
.
1. Suppose I would like to use package *foreach*, can I use current
Sys.time as a seed?
Although I can get the time up to1e-6 second precesion, the code below dose
not work well on a local machine with two cores. #################
library(foreach)
library(snow)
2015 Feb 18
4
Different serialization of functions in interactive vs. batch mode
Hi Luke,
Ah - I see - thank you! This at least points me to a way on how to
"fix" this. I tried setting the srcref attribute to NULL, but the hash
value is still different and so is the serialization. So this looks
like it is one difference, but not all of them
Even if all differences were identified - it still leaves me with
different behavior between interactive and batch-mode,
2012 Jun 16
2
A basic design question for R
Hello R Community,
I have the following design question. I have a data set that looks
like this (shortened for the sake of example).
Gender Age
M 70
F 65
M 70
Each row represents a person with an age/gender combination. We could
put this data into a data frame.
Now, I would like to do some actuarial analysis on this data set. To
do so, I need to create and store
2001 Oct 05
1
nls() fit to a lorentzian - can I specify partials?
First, thanks to all who helped me with my question about rescaling axes
on the fly. Using unlist() and range() to set the axis ranges in advance
worked well. I've since plotted about 300 datasets with relative ease.
Now I'm trying to fit a lossy oscillator resonance to (the square root of)
a lorentzian (testframe$y is oscillator amplitude, testframe$x is drive
frequency):
lorentz
2006 Dec 20
4
R windows crash (PR#9426)
Full_Name: Robert Denham
Version: R-2.4.1
OS: Windows Xp
Submission from: (NULL) (61.88.57.1)
R gui exits without warning when I run a function which has an argument with a
default that is not found.
This was a result of an error in a function I wrote, but I thought that it
should exit more gracefully than it does. Here is an example:
testfun <- function(aa=aa) {
aa <-
2013 Feb 26
1
Could R help with locating coordinates in a serial manner?
Dear R community,
My question is not a quick fix one but it would be helpful if you have any
advice for me.
I have a large data set of many locations in the US and all of these
locations are expressed in coordinates (longitudes and latitudes). I need a
tool which returns the state that each location is situated in. So the
program should return me a vector of state names (eg. NY,CA,OH, etc).
2015 Feb 18
2
Different serialization of functions in interactive vs. batch mode
Hi,
I posted this question to the regular help list, but it seems to be
this is probably a question that is better addressed on r-devel. Sorry
for the double posting.
I am using hash-values to cache certain results in R. This caching
also depends on the hash-value of the function that is being cached
(calculated using the digest package). I noticed that computations
that should already be cached
2013 Jan 14
2
The three-dot question
Dear all,
Why does not the three-dot accept arguments from the parent environment?
I am just confused with this error, can someone give me a hint?
> rm(list=ls())
> testFun <- function(a, ...)
+ {
+ if(a){
+ print(a)
+ }else
+ {
+ print(b)
+ }
+ }
>
> myTask <- function(a)
+ {
+ b <- 3
+ testFun(a, b = b)
+ }
>
2015 Feb 18
1
Different serialization of functions in interactive vs. batch mode
Hi Gabriel,
thanks for your reply - it does solve the problem of my toy function,
but does come with some other problems though.
a) as.list(f)[[1]] yields an expression, not a function. In order to
go the route you are suggesting, I would more likely use "deparse" in
order to get the original back
b) and more seriously - as.list strips the environment of the function
(and thus
2009 Sep 16
3
apply function across two variables by mult factors
Greetings,
I am attempting to run a function, which produces a vector and
requires two input variables, across two nested factor levels. I can
do this using by(X, list(factor1, factor2), function), however I
haven't found a simple way to extract the list output into an
organized vector form. I can do this using nested loops but it isn't
exactly an optimal approach.
Thank you
2005 Aug 17
4
accesing slots of S4 class in C code
I am trying to use a custom S4 object in my C code and I cannot get the
access to its slots working.
The following is a toy example, but even this crashes.
In R I have:
setClass("pd", representation(data="numeric"))
x <- new("pd", data=1:5)
test <- function(pd.obj) {
res <- .C("TestFun", pd.obj)
res}
test(x)
(Of couse
2009 Sep 24
1
how to make a function recognize the name of an object/vector given as argument
Dear guRus,
I'd like to learn how to make a function recognize the name of an
object/vector given as argument
If I have :
testFun <- function(x,y) plot(x,y, main=paste("plot
of",names(x),"and",names(y)) ) # this just a simple example ...
a1 <- 5:8
b1 <- 9:6
testFun(a1,b1)
# Returns the plot, but not the names of the objects/vectors given as
arguments,
# but
2004 Apr 08
1
Why are Split and Tapply so slow with named vectors, why is a for loop faster than mapply
First, here's the problem I'm working on so you understand the context. I
have a data frame of travel activity characteristics with 70,000+ records.
These activities are identified by unique chain numbers. (Activities are
part of trip chains.) There are 17,500 chains.
I use the chain numbers as factors to split various data fields into lists
of chain characteristics with each element of