Displaying 20 results from an estimated 10000 matches similar to: "splitting character vectors into multiple vectors using strsplit"
2012 Jul 28
1
using save() to work with objects that exceed memory capacity
Context: I'm relatively new to R and am working with very large datasets.
General problem: If working on a dataset requires that I produce more than
two objects of roughly the size of the dataset, R quickly uses up its
available memory and slows to a virtual halt.
My tentative solution: To save and remove objects as they're created, and
load them when I need them. To do this I'm
2010 Oct 04
1
Splitting a DF into rows according to a column
Hi,
I'm turning my wheels on this and keep coming around to the same wrong
solution - please have a look and give a hand ...
The premise is: a DF like so
> loremIpsum <- "Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Quisque leo ipsum, ultricies scelerisque volutpat non, volutpat et nulla.
Curabitur consequat ullamcorper tellus id imperdiet. Duis semper malesuada
2000 Mar 07
3
Merging data.frames
On Tuesday, March 07, 2000 5:40 PM, Richard Bilonick wrote:
>I need to merge several data.frames into one data.frame. In S-Plus I would
>use
>"merge" but I don't see a merge command in R. What is the best way to
>accomplish
>this?
The easiest way to to this, I think, is as follows:
if you have several data frames, dataframe1, dataframe2, . . . , dataframen,
you
2005 Dec 22
1
strsplit with dataframes
Hello fellow R people,
I can not figure out a pretty way to use strplit with vectors
Imagine that I got the following data from someone with ID's
representing several factors
ID data
A1-B1-t1 0
A1-B1-t2 1
A1-B2-t1 5
A1-B2-t2 10
A1-B10-t1 0
A1-B10-t2 1
A1-B20-t1 5
A1-B20-t2 10
...
I would like to turn this dataframe to
station substation time data
A1 B1 t1 0
A1 B1 t2 1
A1 B2 t1 5
2007 Nov 02
1
R timeDate does not allow seconds?
Hello, Sorry if anyone gets this message twice, as my mailserver may not
be working.
Thanks for your response. Your idea makes a lot of sense to me, but I've
been unable to get seconds to work.
I ended up with this format finally:
"2007-10-31_16:20:22"
Problem is I am unable to get it recognized as a date using timeDate():
R>
2009 Nov 10
3
creating multiple plots using a splitting factor
Hello,
I am new to R. I often collect data at multiple sites and need to
create separate graphs (such as scatterplots or histograms) of specific
variables for each site. I have tried to do this by splitting the data
frame and then using lapply, but it seems that the graphing commands
cannot be called as functions. Here is a sample of my data, called
"seeddist2":
site
2018 Feb 12
2
[parallel] fixes load balancing of parLapplyLB
Dear R-Devel List,
**TL;DR:** The function **parLapplyLB** of the parallel package has [reportedly][1] (see also attached RRD output) not
been doing its job, i.e. not actually balancing the load. My colleague Dirk Sarpe and I found the cause of the problem
and we also have a patch to fix it (attached). A similar fix has also been provided [here][2].
[1]:
2018 Feb 19
2
[parallel] fixes load balancing of parLapplyLB
Hi, I'm trying to understand the rationale for your proposed amount of
splitting and more precisely why that one is THE one.
If I put labels on your example numbers in one of your previous post:
nbrOfElements <- 97
nbrOfWorkers <- 5
With these, there are two extremes in how you can split up the
processing in chunks such that all workers are utilized:
(A) Each worker, called
2018 Feb 26
2
[parallel] fixes load balancing of parLapplyLB
Dear Christian and Henrik,
thank you for spotting the problem and suggestions for a fix. We'll
probably add a chunk.size argument to parLapplyLB and parLapply to
follow OpenMP terminology, which has already been an inspiration for the
present code (parLapply already implements static scheduling via
internal function staticClusterApply, yet with a fixed chunk size;
parLapplyLB already
2009 Jan 27
1
Mystery Error in midnightStandard
I wasn't even aware I was using midnightStandard. You won't find it in my
script.
Here is the relevant loop:
date1 = timeDate(charvec = Sys.Date(), format = "%Y-%m-%d")
date1
dow = 3;
for (i in 1:length(V4) ) {
x = read.csv(as.character(V4[[i]]), header = FALSE, na.strings="");
y = x[,1];
year = V2[[i]];
week = V3[[i]];
dtstr =
2008 Jan 24
1
Error using Rmetrics to read data
Hi folks. This set of code used to work, but after upgrading to the
latest version of Rmetrics it no longer does. Any ideas?
SP500<-read.table("SP500.csv",header=TRUE,sep=",")
> head(SP500)
Date Open High Low Close Volume Close2
1 8/4/2006 1280.26 1292.92 1273.82 1279.40 2530970112 1279.40
2 8/3/2006 1278.22 1283.96 1271.25 1280.27
2012 Jul 31
1
ways of getting around allocMatrix limit?
I need to multiply to very large, nonsparse matrices, and so get the
error "allocMatrix: too many elements specified".
Is there a way to set the limit for allocMatrix?
In my case, the two matrices, A and B, are nxm and mxp where m is
small, so I could subdivide each into blocks of submatrices
A=rbind(A1,A2,...) and B=cbind(B1,B2,...) then multiply each pair of
submatrices, but I was
2008 Aug 18
1
Converting monthly data to quarterly data
Dear R users,
I have a dataframe where column is has countries, column 2 is dates
(monthly) for each countrly, the next 10 columns are my factors where I have
measurements for each country and for each date. I have attached a sample
of the data in csv format with the data for 3 countries.
I would like to convert my monthly data into quarterly data, finding the
mean over 3 month periods for
2009 Jan 27
2
Can I create a timeDate object using only year and week of the year values?
For a model I am working on, I have samples organized by year and week of
the year. For this model, the data (year and week) comes from the basic
sample data, but I require a value representing the amount of time since the
sample was taken (actually, for the purpose of the model, it is sufficient
to use the number of weeks from the middle of the sample week to the
present).
What I have found so
2018 Mar 15
2
clusterApply arguments
Thank you for your answer!
I agree with you except for the 3 (Error) example and
I realize now I should have started with that in the explanation.
>From my point of view
parLapply(cl = clu, X = 1:2, fun = fun, c = 1)
shouldn't give an error.
This could be easily avoided by using all the argument
names in the custerApply call of parLapply which means changing,
parLapply <-
2005 Oct 28
3
splitting a character field in R
Dear R users,
I have a dataframe with one character field, and I would like to create two
new fields (columns) in my dataset, by spliting the existing character
field into two using an existing substring.
... something that in SAS I could solve e.g. combining substr(which I am
aware exist in R) and "index" for determining the position of the pattern
within the string.
e.g. if my
2012 Mar 01
3
Converting a string vector with names to a numeric vector with names
Not paying close attention to detail, I entered the equivalent of
pstr<-c("b1=200", "b2=50", "b3=0.3")
when what I wanted was
pnum<-c(b1=200, b2=50, b3=0.3)
There was a list thread in 2010 that shows how to deal with un-named vectors, but the same
lapply solution doesn't seem to work here i.e.,
pnum<-lapply(pstr, as.numeric)
or similar vapply
2018 Mar 15
1
clusterApply arguments
On 03/15/2018 05:25 PM, Henrik Bengtsson wrote:
> On Thu, Mar 15, 2018 at 3:39 AM, <FlorianSchwendinger at gmx.at> wrote:
>> Thank you for your answer!
>> I agree with you except for the 3 (Error) example and
>> I realize now I should have started with that in the explanation.
>>
>> From my point of view
>> parLapply(cl = clu, X = 1:2, fun = fun, c =
2013 Mar 13
5
string split at xth position
Hi,
I have a vector of strings like:
c("a1b1","a2b2","a1b2") which I want to spilt into two parts like:
c("a1","a2","a2") and c("b1","b2,"b2"). So there is
always a first part with a+number and a second part with b+number.
Unfortunately there is no separator I could use to directly split
the vectors.. Any idea
2013 Apr 25
2
Decomposing a List
Greetings!
For some reason I am not managing to work out how to do this
(in principle) simple task!
As a result of applying strsplit() to a vector of character strings,
I have a long list L (N elements), where each element is a vector
of two character strings, like:
L[1] = c("A1","B1")
L[2] = c("A2","B2")
L[3] = c("A3","B3")