Displaying 20 results from an estimated 7000 matches similar to: "Time problems (POSIXct)"
2006 Jun 23
3
Problems with weekday extraction from zoo objects
Hi Folks!
I'm struggling with dates - but enough about my personal life.....
I have two daily time series files. In one (x) the date format is Y/m/d
and the other (y) is d/m/y. I used read.zoo on both and they read into
R with no problem.
Then I use: weekdays(as.Date(x$DATE)) and get what I expect - all the
days of the week in my data set.
When I use:
2012 Nov 23
3
daily maximum temperature
Hello,
I want to filter the daily maximum temperature. For this i made this
skript, but it come out wrong results. Can anybody help me?
Thanks for your help!
Best regards
datos$X <- as.POSIXct(strptime(datos$X, "%d/%m/%Y %H:%M:%S"))
z <- aggregate(zoo(datos$Ta), as.POSIXct(datos$X), max)
> str(datos)
'data.frame': 17137 obs. of 5 variables:
$ X : Factor w/
2013 Mar 08
2
Zoo Data
Hi Jakob,
dat1<-read.table(text="
TIME, Value1, Value2
01.08.2011 02:30:00, 4.4, 4.7
01.09.2011 03:00:00, 4.2, 4.3
01.11.2011 01:00:00, 3.5, 4.3
01.12.2011 01:40:00, 3.4, 4.5
01.01.2012 02:00:00, 4.8, 5.3
01.02.2012 02:30:00, 4.9, 5.2
01.08.2012 02:30:00, 4.1, 4.7
01.12.2012 03:00:00, 4.7, 4.3
01.01.2013 01:00:00, 3, 4.3
01.01.2013 01:30:00, 3.8, 4.1
01.01.2013 02:00:00, 3.8,
2008 Oct 01
9
time segments intersection
Hi all,
Please, how could I calculate the time that two time segments has in
common? Is there any function to perform this calculation?
For instance, given four POSIXlt objects...
endPeriod<-as.POSIXlt("2008-09-30")
startPeriod<-as.POSIXlt("2007-10-01")
endProject<-as.POSIXlt("2007-05-31")
startProject<-as.POSIXlt("2006-12-01")
that limit
2006 Jul 08
2
String mathematical function to R-function
hello
I make a subroutine that give-me a (mathematical)
function in string format.
I would like transform this string into function ( R
function ).
thanks for any tips.
cleber
#e.g.
fun_String = "-100*x1 + 0*x2 + 100*x3"
fun <- function(x1,x2,x3){
return(
############
evaluation( fun_String )
############
)
True String mathematical function :-( :-(
> nomes
[1]
2009 Nov 09
3
How to transform the Matrix into the way I want it ???
Hi, R users,
I'm trying to transform a matrix A into B (see below). Anyone knows how to
do it in R? Thanks.
Matrix A (zone to zone travel time)
zone z1 z2 z3 z1 0 2.9 4.3 z2 2.9 0 2.5 z3 4.3 2.5 0
B:
from to time z1 z1 0 z1 z2 2.9 z1 z3 4.3 z2 z1 2.9 z2 z2 0 z2 z3 2.5 z3 z1
4.3 z3 z2 2.5 z3 z3 0
The real matrix I have is much larger, with more than 2000 zones. But I
think it should
2011 Mar 29
5
Integration with variable bounds
If this is posted elsewhere I cannot find it. I need to perform multiple
integration where some of the variables are in the bounds of the other
variables. I was trying to use R2Cuba function but cannot set the upper and
lower bounds. My code so far is :
int <- function(y){
u2 = y[1]
z2 = y[2]
u1 =y[3]
z1 = y[4]
ff <- u1*(z1-u1)*u2*(z2-u2)*exp(-0.027*(12-z2))
return(ff)
}
2012 Aug 08
3
help, please! matrix operations inside 3 nested loops
hello, this is my script:
#1) read in data:
daten<-read.table('K:/Analysen/STRUCTURE/input_STRUCTURE_tab_excl_5_282_559.txt',
header=TRUE, sep="\t")
daten<-as.matrix(daten)
#2) create empty matrix:
indxind<-matrix(nrow=617, ncol=617)
indxind[1:20,1:19]
#3) compare cells to each other, score:
for (s in 3:34) { #walks though the matrix colum by colum, starting at
2006 Jun 15
3
matrix selection return types
Dear Rusers,
I would like some comments about the following results
(under R-2.2.0)
> m = matrix(1:6 , 2 , 3)
> m
[,1] [,2] [,3]
[1,] 1 3 5
[2,] 2 4 6
> z1 = m[(m[,1]==2),]
> z1
[1] 2 4 6
> is.matrix(z1)
[1] FALSE
> z2 = m[(m[,1]==0),]
> z2
[,1] [,2] [,3]
> is.matrix(z2)
[1] TRUE
Considered together, I'm a bit surprised about
2002 Mar 27
2
Error with nls
Dear R-group members,
I use:
platform i386-pc-mingw32
arch x86
os Win32
system x86, Win32
status
major 1
minor 4.1
year 2002
month 01
day 30
language R
I try to fit a 2 compartment model. The compartments are open, connected
to each other and
2008 Oct 04
3
How to plot countours with fixted densities?
Hello,
I used the following codes to generate bivariate normal dependence structure with unit Frechet margins.
Sigma <- matrix(c(1,.5*sqrt(1),.5*sqrt(1),1),2,2) # generate
y <- mvrnorm(Nsam, c(0,0), Sigma) # random
v <- cbind(pnorm(y[,1],mean = 0, sd = 1), pnorm(y[,2],mean = 0, sd = 1))
z <- cbind(-1/log(v[,1]),-1/log(v[,2]))
z1 <- z[,1]
z2 <- z[,2]
And to
2013 Oct 18
1
crr question in library(cmprsk)
Hi all
I do not understand why I am getting the following error message. Can
anybody help me with this? Thanks in advance.
install.packages("cmprsk")
library(cmprsk)
result1 <-crr(ftime, fstatus, cov1, failcode=1, cencode=0 )
one.pout1 = predict(result1,cov1,X=cbind(1,one.z1,one.z2))
predict.crr(result1,cov1,X=cbind(1,one.z1,one.z2))
Error: could not find function
2017 Jul 28
3
problem with "unique" function
I have the joint distribution of three discrete random variables z1, z2 and
z3 which is captured by "z"
and "prob" as described below.
For example, the probability for z1=0.46667, z2=-1 and z3=-1 is 2.752e-13.
Also, the probability adds up to 1.
> head(z) z1 z2 z3
[1,] -0.46667 -1.0000 -1.0000
[2,] -0.33333 -0.9333 -0.9333
[3,] -0.20000 -0.8667 -0.8667
2006 Jun 14
3
A question about stepwise procedures: step function
Dear all,
I tried to use "step" function to do model selection, but I got an error massage. What I don't understand is that data as data.frame worked well for my other programs, how come I cannot make it run this time. Could you please tell me how I can fix it?
***************************************************************************************************
2008 Jul 11
1
Comparing complex numbers
Is there an easy way to compare complex numbers?
Here is a small example:
> (z1=polyroot(c(1,-.4,-.45)))
[1] 1.111111-0i -2.000000+0i
> (z2=polyroot(c(1,1,.25)))
[1] -2+0i -2+0i
> x=0
> if(any(identical(z1,z2))) x=99
> x
[1] 0
# real and imaginary parts:
> Re(z1); Im(z1)
[1] 1.111111 -2.000000
[1] -8.4968e-21 8.4968e-21
> Re(z2); Im(z2)
[1] -2
2006 Mar 16
2
Using of LME function in non-replicate data
Hello all R-users!
In Jun-2005, I find the follow discussion about using
of
LME function ( in NLME library ) for fitting
non-replicate data
The thread: ANOVA vs REML approach to variance
component estimation
http://tolstoy.newcastle.edu.au/R/help/05/06/6498.html
Someone expose the follow problem:
# non-replicate data
y <- c(2.2, -1.4, -0.5, -0.3, -2.1, 1.5, 1.3, -0.3,
0.5, -1.4,
2008 Apr 03
3
summary(object, test=c("Roy", "Wilks", "Pillai", ....) AND ellipse(object, center=....)
Dear All,
I would be very appreciative of your help with the following
1). I am running multivariate multiple regression through the manova() function (kindly suggested by Professor Venables) and getting two different answers for test=c("Wilks","Roy","Pillai") and tests=c("Wilks","Roy",'"Pillai") as shown below. In the
2006 Jan 27
1
about lm restrictions...
Hello all R-users
_question 1_
I need to make a statistical model and respective ANOVA table
but I get distinct results for
the T-test (in summary(lm.object) function) and
the F-test (in anova(lm.object) )
shouldn't this two approach give me the same result, i.e
to indicate the same significants terms in both tests???????
obs.
The system has two restrictions:
1) sum( x_i ) = 1
2) sum(
2005 Jun 02
4
plot/lm/abline
Hi,
when I run
> plot.default(z1, z2, xlab = "x", ylab = "y", main = "xxxx", pch = "+")
> abline(lm(z1 ~ z2))
then the plot is plotted perfectly (scatterplot), however, the lm()
function doesnt appear on the plot. What could be wrong?
(Yesterday it worked perfectly, with the lm() line.)
Running R 2 on OS X.
Mathias Hunsk??r Furevik
Norway
2004 Mar 10
1
Shorewall2 - Action commands
Dear All,
I have read all the documentation I can find but I still have not understood how, in what context and where to use the action commands enumerated in /usr/share/shorewall/actions.std.
Illustrating with SMB traffic for instance, how can one use AllowSMB, DropSMB and RejectSMB to control SMB traffic instead of the classic
ACCEPT z1 z2 udp 135,445
ACCEPT z1