search for: drift

...en I try to perform a forecast of an ARIMA model produced by an auto.arima function. Here is what I'm doing: c<-auto.arima(fil[[1]],start.p=0,start.q=0,start.P=0,start.Q=0,stepwise=TRUE,stationary=FALSE,trace=TRUE) # fil[[1]] is time series of monthly data ARIMA(0,0,0)(0,1,0)[12] with drift : 1725.272 ARIMA(0,0,0)(0,1,0)[12] with drift : 1725.272 ARIMA(1,0,0)(1,1,0)[12] with drift : 1694.301 ARIMA(0,0,1)(0,1,1)[12] with drift : 1e+20 * ARIMA(1,0,0)(0,1,0)[12] with drift : 1729.999 ARIMA(1,0,0)(2,1,0)[12] with drift : 1693.12 ARIMA(...

Hello everyone! I been observing some peculiar time drift on my Xen domains (dom0 and domUs). The time (as returned by timeofday) on my domains drifts at an almost steady rate from the real time ( as read from the time stamp counter ). The drift is so constant that it makes me think there should be some simple explanation for it in the way Xen keeps tim...

The time appears to be perfect inside dom0, however all the domU''s tend to have a slightly faster date which gets further out of sync every day. I''m currently using Xen 3.0.3 with Gentoo Linux, under 3.0.2 I had no problems with domU clocks. Are there any known issues which could cause this? I''d strongly prefer not to run ntpd in every domU, having all domU clocks in

Hi, I've noticed that one of my new servers (new mobo) if drifting slowly backwards in time (in aprox. 24 hours, system time drifts back 5 minutes). I have an ntpd process which is supposed to sync with a lan time server but it's not quite working. So I'm launching a manual ntpdate or ntp-client once an hour and that seems to work. However, suppose I...

Hi On 5.3 i have a situation where some boxes have been 3 or 4 seconds out and restarting ntpd has fixed the issue. What i dont understand is why the clocks did not drift to the correct time when the config seems correct in that restarting ntp did correct the time. Is there something 'special' i need to do in order for the drift to work? $ cat /etc/ntp.conf restrict default ignore restrict 127.0.0.1 restrict 10.0.0.0 mask 255.0.0.0 n...

In reading the Xen list there are frequent postings regarding NTP time drift issues for virtualized guests, correct configurations, etc. We have a solution (no cost) for monitoring time drift of hosts for anyone needing to do so or to determine whether their environment is maintaining time synchronization. For etiquette I am not publishing the information to the list ma...

Hi Steve, Have you read this paper? (Heping Ding, David I. Havelock, Drift-Compensated Adaptive Filtering for Improving Speech Intelligibility in Cases with Asynchronous Inputs. EURASIP J. Adv. Sig. Proc. 2010:) Let me call is paper-Drift. It provided a method to evaluate Relative Sample Offset (RSO, d[i]) which is omitted in the microsoft paper (Challenges and Solutions...

1. Shouldn''t the GPLPV drivers take care of the (bad) clock drift I''m experiencing in my Windows XP HVM? Or is there some other way around this problem that I haven''t been able to find on Google? How can I tell if the GPLPV drivers are active? I''ve added the /gplpv switch to the boot.ini file and the virtual NIC is definitely using the...

Dear R-Users, I have the following problem to solve and I wonder if there are means in R that can help me. At irregular time intervals I observe a random walk process, Y, with time-varying drift. I assume that the drift, D, is a (linear) function of some parameter X. The goal is to estimate D(X). I could regress Y_{t+dt} - Y_{t} ~ X, but it's probably not appropriate since Var(Y_{t+dt} - Y_{t}) is not constant (actually in theory it is proportional to dt). Any suggestions? Thank you...

...te changes can affect a processor core''s Time Stamp Counter (TSC) which some operating systems may use as a part of their time keeping algorithms. Most modern operating systems are well aware of the effect of these state changes on the TSC and the potential for TSC drift[3] across multiple processor cores and properly account for it. Although cores may drift with respect to one another, an individual core''s TSC is always monotonically increasing. This drift can *not* occur on single-processor single-core platforms. This note reviews a few cor...

Hello, On a xenserver with several (39) domUs, we experience problems with the system clock of the domUs. The clock seems to drift away several seconds up to two minutes from the dom0 clock. We do have set independent_wallclock=0. According to the docs (i.e. http://wiki.xensource.com/xenwiki/InstallationNotes) that way domUs should use the dom0 clock, but apparently that''s not the case. permitted_clock_jitter is set...

Dear list(s), we are running a cluster of virtual machines on ganeti 2.15.2 on top of qemu-kvm 2.1.2. Hosts are Debian jessie (Kernel 3.16). We have big trouble with timekeeping on guests, no matter if these guests are lenny, squeeze, wheezy or jessie. Clock drifts heavily on some, others are fine. There is no obvious pattern on which guest this happens and on which not, but it seems the clock drifts heavier on guests that are idle and have nothing to do. Some more facts: * Clocksource on all hosts are set to tsc * Clocksource on all guests are set to kvm-c...

Dear list(s), we are running a cluster of virtual machines on ganeti 2.15.2 on top of qemu-kvm 2.1.2. Hosts are Debian jessie (Kernel 3.16). We have big trouble with timekeeping on guests, no matter if these guests are lenny, squeeze, wheezy or jessie. Clock drifts heavily on some, others are fine. There is no obvious pattern on which guest this happens and on which not, but it seems the clock drifts heavier on guests that are idle and have nothing to do. Some more facts: * Clocksource on all hosts are set to tsc * Clocksource on all guests are set to kvm-c...

...nd about client/server clock syncs. If I connect to the stream with a fresh browser, I can measure between 5-10 secs latency. I keep listening to it for while, and the delay between server and client grows as listening is going on. As pointed out Philipp yesterday to me, it's approximately a 5% drift, apparently caused by the client audio card clock. But, then since there are no cuts in the sound as I am listening, it means the audio rate is lower than the 22kHz of the files, right ? And a 5% drift at 22kHz is around 1kHz difference ! And even if I did not properly measured this behavior, I am...

...lue in the archived help. Also, how do I retrieve the AICs of each tried model in auto.arima? The purposes are (1) to output to a text file, and (2) to find the 2nd best model by finding 2nd lowest AIC instead of eyeballing thru the value at the console screen. For those models with drift, how can I find out what are the drifts? For example, eyeballing thru, my 2nd best model is ARIMA(1,1,1) with drift but it didn't state what is the drift. Many thanks. > modelarima <- auto.arima(Price[1:nTrain], trace=TRUE) ARIMA(2,1,2) with drift : 4417.541 A...

...nrow(depVar)) [1] 545 > (nTest <- nInstance + nHorizon - 1) #number of latest points reserved for testing [1] 13 > (nTrain <- nrowDepVar - nTest) [1] 532 First I use auot.arima to find the best (p,d,q). > modArima <- auto.arima(depVar[1:nTrain,], trace=TRUE) ARIMA(2,1,2) with drift : 4402.637 ARIMA(0,1,0) with drift : 4523.553 ARIMA(1,1,0) with drift : 4410.036 ARIMA(0,1,1) with drift : 4442.558 ARIMA(1,1,2) with drift : 4401.178 ARIMA(1,1,1) with drift : 4399.421 ARIMA(1,1,1) : 4398.502 ARIMA(0,1,1)...

Hello, I have a question on unit root test with urca toolbox. First, to run a unit root test with lags selected by BIC, I type: > CPILD4UR<-ur.df(x1$CPILD4[5:nr1], type ="drift", lags=12, selectlags ="BIC") > summary(CPILD4UR) The results indicate that the optimal lags selected by BIC is 4. Then I run the same unit root test with drift and 4 lags: > CPILD4UR1<-ur.df(x1$CPILD4[5:nr1], type ="drift", lags =4) > summary(CPILD4UR1...

We have a local time server and all of our machines are pointed at it for the time. How can the clock drift by a day and a half? [root at devserver21 ~]# date Fri Aug 13 14:43:29 EDT 2010 [root at devserver21 ~]# rdate -s 192.168.1.67 [root at devserver21 ~]# date Thu Aug 12 07:02:39 EDT 2010 [root at devserver21 ~]# cat /etc/ntp.conf | grep -v ^# | grep -v ^$ restrict default nomodify notrap noquery re...

...never > noticed it until today - > www.iwaenc.org/proceedings/*2008*/contents/papers/9044.pdf > > That paper is from people at MS describing, in some detail, what the > Windows kernel echo canceller does to handle synchronisation issues. It > tracks both time varying sample clock drift and hiccups in the sample > streams. It seems to handle the drift in a fairly similar manner to the > several other papers on the topic from the past 10 years. It (Challenges and Solutions for Designing Software AEC on Personal Computers) is a good paper. But some critical details were omitt...

...Engineering, so please bear with me if this is a silly question. I'm trying to assess whether the results of an experiment satisfy the hypothesis of homoscedasticity (my ultimate goal is to use ANOVA). The result of the experiment is mean delay (dT), which depends on three factors, topology, drift, and lambda. The first two factors are categorical (with 4 levels each) and the last one is numerical, with two levels. A sample of my data is as follows: dT Topology Drift lambda 258.789 Tree b1 .43 244.195 Tree b1 .43 115.961 Tree b2 .3 115.183 Tree b2 .3 I would like to separa...