Displaying 12 results from an estimated 12 matches similar to: "Date Time Objects"
2012 Mar 30
1
lubridate:ymd_hm and coercion of class POSIXct. Smooth way to restore the date format.
Dear all,
I wish to create a POSIXct variable from date and time variables using the ymd_hm function in package lubridate. In some cases data for time is missing, which causes a problem for ymd_hm. I wish to find a smooth way to handle this.
# Some example data:
x <- data.frame(date = c("2011-09-22", "2011-07-28"), time = c("15:00", NA))
x
# paste date and
2011 Feb 02
0
Need help subsetting time series data
Hi all,
I have multiple datasets of time series data taken from GPS collars. The
collars are supposed to take a fix every hour on the half hour, i.e., 0:30,
1:30, 2:30...23:30, (because it sometimes takes longer for the collars to
acquire a location the minute of these locations vary from 30-34) but
because of a software glitch in the collars, at random times the collars
start taking multiple
2010 Oct 15
3
Create Arrays
Hi,
For this example:
O <- c(0 0 0 2 0 0 2 0)
I want to create an array every time O[i] > 0. The array should be in the
form;
R[j] <- array(-1, dim=c(2,O[i]))
i.e. if O[i] > 0 4 times I want 4 R arrays.
Does anyone have any suggestions?
Thanks,
Doug
--
View this message in context: http://r.789695.n4.nabble.com/Create-Arrays-tp2996706p2996706.html
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2011 Mar 08
4
If Statement
Hi,
I am having some problems using the if statement correctly. I have used it
many times previously so I dona't know what is different with this case.
Here is my problem:
I have a 1X10 matrix of values as follows:
> H.MC
[,1]
[1,] 4.257669
[2,] 7.023242
[3,] 4.949857
[4,] 5.107000
[5,] 4.257669
[6,] 4.257669
[7,] 4.257669
[8,] 4.257669
[9,] 4.257669
[10,] 4.257669
2010 Oct 13
1
Data Gaps
R community,
I am trying to write a code that fills in data gaps in a time series. I
have no R or statistics background at all but the use of R is proving to be
a large portion of my PhD research.
So far my code identifies where and the number of new entries required but I
do not know how to add additional rows or columns into an array. Any advice
on how this can be done?
Here is an example:
2010 Nov 10
3
Plot Axes
R community,
I am creating a bivariate return level plot by adding calculated return
period values as lines onto an existing plot using the following code with
the points representing the return periods.
plot(H2,D2,pch="+",axes=TRUE)
points(H.10,D.10, type="l",col="blue")
points(H.20,D.20, type="l",col="green")
points(H.50,D.50,
2010 Oct 15
0
nomianl response model
Is there a way to estimate a nominal response model?
To be more specific let's say I want to calibrate:
\pi_{v}(\theta_j)=\frac{e^{\xi_{v}+\lambda_{v}\theta_j}}{\sum_{h=1}^m
e^{\xi_{h}+\lambda_{h}\theta_j}}
Where $\theta_j$ is a the dependent variable and I need to estimate
$\xi_{h}$ and $\lambda_{h}$ for $h \in {1...,m}$.
Thank you,
Mauricio Romero
Quantil S.A.S.
Cel: 3112231150
2010 Oct 25
2
difftime error
R community,
I am trying to create an array of the time differences between datapoints
for a very large set. For some reason for 4 of the values the difference
has been calculated as NA.
Looking at the individual points two of them are "1981-03-29 01:40:00" and
"1981-03-29 02:00:00"
This is the exact same format as the other points that return values of 20
mins as expected.
2011 Feb 04
3
uniroot
Hi,
I am using the uniroot function in order to carry out a bivariate Monte
Carlo simulation using the logistics model.
I have defined the function as:
BV.FV <- function(x,y,a,A)
(((x^(-a^-1)+y^(-a^-1))^(a-1))*(y^(a-1/a))*(exp(-((1^(-a^-1)+y^(-a^-1))^a)+y^-1)))-A
and the procedure is as follows:
Randomly generate values of A~(0,1), y0 = -(lnA)^-1
Where: A=Pr{X<xi|Y=yi-1} and a is the
2006 May 24
2
DHCP configuration for Cisco 7960?
(Apologies to those Toronto Asterisk Users' Group folks who have seen
this message... I figured I'd have more success with a wider audience)
I'm trying to boot a Cisco 7960 from an ISC DHCPD server (3.0.3 on
FreeBSD 4.11), so far unsuccessful, and getting some odd behaviour on
the wire. I wonder if anyone has done this before and therefore can
validate whether or not the traffic I am
2004 Jul 01
9
Config Files
Im having a trouble understanding the config files setup even with some documentation ive read such as the handbook, maybe im just illiterate. Anyway do you think some one can point me to some examples of real config files. Such as IAX, Extensions, and Sip. I just cant grasp the concept for some reason. If someone would like to help me out, maybe even explain one on one? Thanks a lot
2017 Aug 14
1
Statistical / data mining methods in R and not in SAS?
Hi, and sorry for asking such an unspecific question.
Does anybody know of statistical / data mining methods that are available in R
that are not in SAS ? With SAS I mean the SAS System Version 9.4 and SAS
Enterprise Miner. I don't expect a complete list, just two or three examples
or hints where and what to look for.
I found some older comparisons, and the R methods mentioned there