Displaying 20 results from an estimated 20000 matches similar to: "cut.POSIXct problem"
2003 May 20
3
plot POSIX class and identify
Hallo all
just a small question I did not find an answer in help pages.
Is it possible to use identify() after plotting with plot.POSIX to
label points and/or to find out some points?
Thanks a lot.
Best regards
Petr Pikal
petr.pikal at precheza.cz
p.pik at volny.cz
2003 Feb 21
2
how to chage values in data frame to NA iside a function
Dear all
I have a function in which I would like to change some values to NA according to
some condition.
dropout<-function(y, nahr=FALSE,...) {
<some stuff for computing an index>
if (nahr) y[index]<<-NA
invisible(index)
}
in case y is a vector all works OK but if it is a part of data frame by calling
dropout(df$y) or dropout(df[,number]) no change is done.
Please can you
2002 Jan 24
5
aggregate, by tapply
Dear R users
I searched some sources but i did not find an answer.Please give
me some hint to following problem.
I would like to compute a summary statistic for some vector for
different factor levels. I know I can use tapply or aggregate but I
do not know if there is a way how to use function with several
(two) variable input (like weighted.mean).
I wrote a simple a function for factor
2003 May 15
2
strptime and non ISO date format
Dear all
I have a character vector of dates something like:
timevec<-c("15.5.2003 00:00", "15.5.2003 00:01", "15.5.2003 00:02",
"15.5.2003 00:03","15.5.2003 00:04")
and I would like to transform it to some more convenient date class. Is there a
way how to do it directly without previous reformating to ISO like structure and
adding a
2001 Aug 14
2
RODBC connection - mixed data types
Dear R users
I use R (1.3.0) Windows version usually with connection to Excel
sheets via RODBC Version: 0.8-2. Everything is OK until I use mixed
data types (numeric and character) in one column.
In that case I will get a particular column of data frame with NA's.
Example
vzorek lpas apas
NA 51.240 20.26
NA 51.340 20.42
NA 49.770 22.05
RB 12 49.840 19.30
RB 12 49.880
2003 Apr 07
1
plot.POSIXct with axes FALSE
Hallo all
I have a question regarding POSIX class objects.
I try tu use as.POSIXct for creating and plotting some time series. To be able to
set labels for time (x) axis I started with plot(..., axes=FALSE) but although it
suppressed all other axes, x axis is still plotted together with labels. Is it a bug?
see
datum.vyber<-seq(ISOdate(2000,1,1), ISOdate(2003,1,1), by="3
2003 Apr 10
1
how to estimate parameters of multimodal distribution
Dear all
Please, is there any function or package for dealing with multimodal distributions?
I try to fit multimodal distribution or more precisely to find out mixture of normal
distributions which can lead to my actual data.
I use optim to find (in that case) two parameters but what I want is to let the
function find out arbitrary number of normal distributions underlaying my actual
data
2002 Sep 19
5
how to use if statement in function correctly
Dear all
I try to persuade if statement in my function to work as I want (but I am not very
successful:(
My question is why my function with if statement is evaluated correctly in case of
atomic variables and incorrectly in case of vector variables.
Here is an example:
#function with if statement
fff <- function(otac,sklon)
{
test <- (otac *
2001 Feb 05
1
read.table("clipboard")
Hallo
Please I have a question regarding read.table. I wonder if there is any
possibility to read a content of 'clipboard' directly (let say as a copy
from Excel like programs) or if it is always necessary to save a file in
an appropropriate format.
I use 1.2.0 W version with W95.
Thank you very much.
Best regards
Petr Pikal
Precheza a.s.
Nabr.Dr.E.Benese 24
tel: 00420 641 25 2257
2003 Jul 16
1
bwplot does something weird with Hmisc library attached
Dear all
I would like to ask you about possible bug in using bwplot (from lattice) together
with Hmisc library attached. I found it in my actual data, but here is a toy
example. It appears only when some levels are missing.
library(lattice)
library(Hmisc)
# preparing data
x1<-rnorm(10,5,1)
x2<-rnorm(10,5,5)
x3<-rnorm(10,1,1)
x4<-rnorm(10,1,5)
x<-c(x1,x2,x3,x4)
x<-c(x,x+5)
2003 Apr 14
1
NA in logical vector = data frame row numbers scrambled
Dear all.
RE how to estimate parameters of multimodal distribution
Thank to prof.Ripley for pointing me to mclust package, although I am not sure I
can apply it to my problem.
I have another question.
I need to change some of my values in data frame to NA.
I use something like
df[df$v1 < 5, 5:10] <- NA
which is OK if there are no NA values in v1.
here are some foo attempts
>
2002 Oct 16
0
peaks
On 15 Oct 2002 at 18:09, Rieckermann Joerg wrote:
> Dear Petr,
>
> I have been fooling around with this peaks function of yours/Ripley
> and don't seem to get the main idea.
>
> What I intend to do is locate the peaks in a vector and later use thes
> values. So the position of the peaks would be of great interest.
>
> My questions:
> * Why does peak retunr a
2001 Oct 18
0
Error term in aov syntax question
Hallo all
I went through all files and through some books I have, but still I am not
completely sure about the correct aov syntax.
Suppose I have a dataset divided to three portions, according to a factor "mereni"
which is a measurement day. There is another factor named "frakce" (Each
sample is divided into three distinct fractions according to its particle size).
samp
2003 Jul 24
3
trellis plot question
Greetings,
Does anyone know how to get an id number in the little header
above each individual plot within a trellis plot? The default
seems to be to print the word id and add a line indicating on
a linear scale where the current id sits.
Thanks in advance for any help you can send,
Suzette
=================================
Suzette Blanchard, Ph.D.
Research Scientist
Frontier Science
2003 Mar 12
7
R help
Dear friends,
I work with Matlab and now a bit in trouble with getting used to R. Could you give me some help with the following questions:
1. how to generate the random matrix mxn with constant mean and variance, say N(0,1)?
2. how to create a code (function), say “myfunction”, and make it available for use every time I run R?
3. how to make a package, say “e1071”, available for use
2002 Jul 26
4
chi square test is not appropriate? but what test is
Hallo all
Suppose I have a summary amount of various colours used in
different areas
colour plastic paint
black 15.5 173.8
brown 6.0 523.2
green 2.5 6.4
red 77.1 237.4
yellow 144.6 77.3
It seems that there are some preferable colours in these two areas
(yellow in plastic, brown an red in paint).
The problem seems to me similar to chi square test but it is
intended for testing counts or
2002 Jul 23
3
Aggregate: assembling the "by" part on the fly
Dear R users,
I'm having trouble using aggregate() and would
greatly appreciate your advice. I am using R 1.5.1
on Windows 2000.
I want to call my function in the following way
extract.data(x=dat[, "Age", "Year"])
where extract.data() uses aggregate() to count the number
of cases for each combination of "Age" and "Year".
I've defined
2002 Jul 19
1
Re RGui and object browser
Hallo Dan
I used your code for ls.objects and it is very usefull. I corrected some typo and it
worked well untill now.
I observed Error due to class evaluation in lists created by aov fit as the fitted
object from aov has two classes (aov and lm)
So I made a little change which seems to work.
Here it is:
# Posted by Dan Putler At 2002-07-15 16:13
# As part of the obveRsive GUI project,
2003 Apr 22
7
Subject: Eliminate repeated components from a vector
X-Mailer: VM 7.00 under 21.4 (patch 6) "Common Lisp" XEmacs Lucid
Reply-To: fjmolina at lbl.gov
FCC: /home/f/.xemacs/mail/sent
Does anyone know how I can eliminate repeated elements from a vector?
2002 Dec 10
2
Variance of a single number
Just out of curiosity, can some please explain the following return NA.
x <- 6
var(x)
y <- c( NA, NA, 10000 )
var(y, na.rm=T)
Unless I am seriously misguided, I believe that the variance of a single
number (i.e. a constant) should be zero. Thanks.
Regards, Adai.