Displaying 20 results from an estimated 5000 matches similar to: "Microseconds for a zoo object?"
2013 Aug 16
1
as.Date.character speed improvement suggestion
R-Devel,
I store and retrieve a large amount of financial data (millions of rows) in a PostgreSQL database keyed by date (and represented in R by class Date). Unfortunately, I frequently find that a great deal of processing time is spent converting dates from character representations to Date class representations in R, presumably because strptime is not fast for large vectors (>10,000
2016 Apr 29
2
selecting columns from a data frame or data table by type, ie, numeric, integer
Good morning RGuru's
I have a data frame of 575 columns.? I want to extract only those columns that are numeric(double) or integer to do some machine learning with.? I have searched the web for a couple of days (off and on) and have not found anything that shows how to do this.?? Lots of ways to extract rows, but not columns.? I have attempted to use "(x == y)" indices extraction
2007 Jun 06
1
fixed effects anova in lme lmer
Can lme or lmer fit a plain regular fixed effects anova? Ie a model without a
random effect, or have there be at least one random effect in order for these
functions to work?
Trying to run such, (1) without specifying a random effect produces an error,
(2) specifying that there is no random effect does not produce the same output
as an anova run in lm(); (2b) specifying that there is no
2016 Apr 29
0
selecting columns from a data frame or data table by type, ie, numeric, integer
> dt1[ vapply(dt1, FUN=is.numeric, FUN.VALUE=NA) ]
a c
1 1 1.1
2 2 1.0
...
10 10 0.2
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Fri, Apr 29, 2016 at 9:19 AM, Carl Sutton via R-help <
r-help at r-project.org> wrote:
> Good morning RGuru's
> I have a data frame of 575 columns. I want to extract only those columns
> that are numeric(double) or integer to do
2023 Nov 03
2
Sum data according to date in sequence
Hi,
I tried this:
# extract date from the time stamp
dt1 <- cbind(as.Date(dt$EndDate, format="%m/%d/%Y"), dt$EnergykWh)
head(dt1)
colnames(dt1) <- c("date", "EnergykWh")
and
my dt1 becomes these, the dates are replace by numbers.
dt1 <- cbind(as.Date(dt$EndDate, format="%m/%d/%Y"), dt$EnergykWh)
dput(head(dt1))
colnames(dt1) <-
2008 May 30
3
Strptime
Hi
This code should explain what I'm trying to do
> strptime("30-Jan-08", "%d-%b-%y")
[1] "2008-01-30"
>
> format(strptime("30-Jan-08", "%d-%b-%y") , "%b-%y")
[1] "Jan-08"
>
> strptime(format(strptime("30-Jan-08", "%d-%b-%y") , "%b-%y") ,
"%b-%y")
[1] NA
I have a
2023 Nov 03
1
Sum data according to date in sequence
Is this what you are after?
library(tidyverse)
library(lubridate)
input <- structure(list(StationName = c("PALO ALTO CA / CAMBRIDGE #1",
"PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1",
"PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE #1",
"PALO ALTO CA / CAMBRIDGE #1", "PALO ALTO CA / CAMBRIDGE
2006 Sep 20
1
seq.Date not accepting NULL length.out (PR#9239)
There seems to be a bug in seq.Date such that it will not allow the user
to pass in length.out =3D NULL, despite the fact that this is the =
default
argument.
For example:
> dt1 <- as.Date("2004-12-31")
> dt2 <- as.Date("2005-12-31")
> seq.Date(dt1, dt2, length.out =3D NULL, by =3D "month")
Error in seq.Date(dt1, dt2, length.out =3D NULL, by =3D
2011 May 10
1
Saving multiple 3x3 TIFF graphics inside a loop
Dear Friends,
I have been trying to save multiple 3x3 (mfrow=c(3,3) graphics inside a loop
using tiff figure format (not using PDF or savePlot functions) with no
success. Could you please help?
Here is a simplified example code:
dat=data.frame (ID=rep(1:10,each=10),IDV=rep(seq(1:10),times=10))
dat$DV <- with(dat, 50+15*IDV)
dat=dat[order(dat$ID,dat$IDV),]
for(i in 1:10){
dt1 =
2007 Nov 12
4
time plotting problem
I am completely misunderstanding how to handle dates.
I want to plot a couple of data series against some
dates. Simple example 1 below works fine.
Unfortunately I have multiple observations per day (no
time breakdowns) and observations across years.
(example 2 very simplistic version )
Can anyone suggest a quick fix or point me to
something to read? I thought that zoo might do it but
I seem
2006 Mar 21
1
rownames, colnames, and date and time
I noticed something surprising (in R 2.2.1 on WinXP)
According to the documentation, rownames and colnames are character vectors.
Assigning a vector of class POSIXct or POSIXlt as rownames or colnames
therefore is not strictly according to the rules.
In some cases, R performs a reasonable typecast, but in some other cases
where the same typecast also would be possible, it does not.
Assigning a
2006 Mar 21
1
rownames, colnames, and date and time
I noticed something surprising (in R 2.2.1 on WinXP)
According to the documentation, rownames and colnames are character vectors.
Assigning a vector of class POSIXct or POSIXlt as rownames or colnames
therefore is not strictly according to the rules.
In some cases, R performs a reasonable typecast, but in some other cases
where the same typecast also would be possible, it does not.
Assigning a
2011 May 01
1
microsecond timestamp support
Does R have support for microseconds in timestamps, e.g. when reading this in
"Time","Include","Kind","Duration"
2011-04-01 14:20:36.368324,Y,U,1.03238296509
2011-04-01 14:20:35.342732,Y,C,0.0252721309662
2011-04-01 14:20:34.337209,Y,R,0.00522899627686
Thanks, Joel
--------------------------------------------------------------------------
- for hire: mac
2006 Jul 03
1
rownames, colnames, and date and time
Hi all
I was wondering whether there has ever been an update on the rownames and
colnames behaviour as described by Eric below?
I still get the same behaviour, exactly as described by Eric, on my WinXP
installation of R-2.3.0. I also posted a message to r-help on Friday but
looking through the online archives it seems to have not made it to the
list. I would agree with Eric that a consistent
2012 Jul 30
1
Possible bug in class 'POSIXlt' when including microseconds?
Dear list,
I'm a bit puzzled by an ambiguity with respect to the representation of
micro-/milliseconds when using 'POSIXlt' objects.
It seems that the last digit of the 'sec' attribute sometimes seems to
differ from the digits shown when printing the 'POSIXlt' object. You'll
find a little SO post with some example code here:
2012 Jun 13
1
histogram fill lattice
Dear all,
I would like to change the "fill" pattern of a histogram using histogram() in the lattice package. I know how to do so using hist(), but would prefer to stay within lattice.
dt1 <- rnorm(100,0,1)
hist(dt1, density=3, angle=45)
library(lattice)
histogram(dt1,
xlab = "Histogram of rnorm(0,1)",
type = "count",
2003 Sep 29
1
CP for rpart
Hi All,
I have some questions on using library rpart. Given my data below, the
plotcp gives me increasing 'xerrors' across different cp's with huge xstd
(plot attached). What causes the problem or it's not a problem at all? I am
thinking 'xerror's should be decreasing when 'cp' gets smaller. Also what
the 'xstd' really tells us? If the error bars for
2012 Mar 05
1
index instead of loop?
Hello,
Does anyone know of a way I can speed this up? Basically I'm attempting to
get the data item on the same row as the report date for each report date
available. In reality, I have over 11k of columns, not just A, B, C, D and
I have to do that over 100 times. My solution is slow, but it works. The
loop is slow because of merge.
# create sample data
z.dates =
2003 Jan 18
1
SAS transport files and the foreign package
Even though the FDA has no policies at all that limit our choices of statistical software, there is one defacto standard in place: reliance of the SAS transport file format for data submission (even though this format is deficient for this purpose, e.g., it does not even document value labels or units of measurement in a self-contained way). Because of the widespread use of SAS transport files in
2013 Apr 24
1
Floating point precision causing undesireable behaviour when printing as.POSIXlt times with microseconds?
Dear list,
When using as.POSIXlt with times measured down to microseconds the default format.POSIXlt seems to cause some possibly undesirable behaviour:
According to the code in format.POSIXlt the maximum accuracy of printing fractional seconds is 1 microsecond, but if I do;
options( digits.secs = 6 )
as.POSIXlt( 1.000002 , tz="", origin="1970-01-01")
as.POSIXlt( 1.999998 ,