similar to: Cross-correlation between two time series data

Displaying 20 results from an estimated 10000 matches similar to: "Cross-correlation between two time series data"

2012 May 11
1
Possible artifacts in cross-correlation function ("ccf")?
Dear R-users, I have been using R and its core-packages with great satisfaction now for many years, and have recently started using the "ccf" function (part of the "stats" package version 2.16.0), about which I have a question. The "ccf"-algorithm for calculating the cross-correlation between two time series always calculates the mean and standard deviation per time
2005 Oct 31
1
how to optimise cross-correlation plot to study time lag between time-series?
Dear R-help, How could a cross-correlation plot be optimized such that the relationship between seasonal time-series can be studied? We are working with strong seasonal time-series and derived a cross-correlation plot to study the relationship between time-series. The seasonal variation however strongly influences the cross-correlation plot and the plot seems to be ?rather? symmetrical (max
2014 Nov 04
1
[R] Calculation of cross-correlation in ccf
Dear All, I am studying some process measurement time series in R and trying to identify time delays using cross-correlation function ccf. The results have however been bit confusing. I found a couple of years old message about this issue but unfortunately wasn't able to find it again for a reference. For example, an obvious time shift is observed between the measurements y1 and y2 when the
2013 Jan 29
1
ccf (cross correlation function) problems
Hello everybody, I am sorry if my questions are too simple or not easily understandable. I’m not a native English speaker and this is my first analysis using this function. I have a problem with a cross correlation function and I would like to understand how I have to perform it in R. I have yearly data of an independent variable (x) from 1982 to 2010, and I also have yearly data of a variable
2011 Mar 11
1
Partial Cross Correlation
Does anyone know of any R code for computing partial cross-correlation? I have examples of cross correlation functions (ccfs) that are not smooth but rather consist of a peak of several high values in consecutive lags, with sharp drops on either side. This indicates that y(t) is a function of some average of x(t-tau) at the set of lags tau over which the ccf is high. I could sort out these
2008 Mar 05
1
Need help for calculating cross-correlation between 4 multivariate time series data
Hi all, I would like to know whether there is any function in R were i can find the cross-correlation of two or more multivariate (time series) data. I tried the function ccf() but it seems like to have two univariate datasets. Please let me know. sincerely, sandeep -- Sandeep Joseph PhD Post Doctoral Associate Center for Tropical & Emerging Global Diseases Paul D. Coverdell Center,
2005 Oct 20
1
Cross-correlation function
Hello All, I'm having trouble with the ccf() function. I am trying to do cross-correlation between two time-series, but I keep getting an error message I don't know what to do with. This what I type and the error message I get: > ccf(ts(mod[,1]),ts(mod[,2]),na.action='na.exclude',type='cor') Error in "colnames<-"(`*tmp*`, value = c("ts(mod[,
2006 Mar 23
1
Cross correlation in time series
Hi list, I'm working on time series of (bio)physical data explaining (or not) the net ecosystem exchange of a system (+_ CO2 in versus CO2 out balance). I decomposed the time series of the various explaining variable according to scale (wavelet decomposition). With the coefficients I got from the wavelet decomposition I applied a (multiple) regression, giving some expected results. The net
2006 Apr 27
1
Comparing two time series?
I have got pairs of time series, where one usually is shorter (n typically about 5400) than the other (n typically about 52000). I would like to calculate the ccf for these series, but I haven't found a smart way to let the shorter "slide" along the longer one in steps. Manually splitting the longer series into shorter ones of the same length as the shorter is possible, but tedious.
2009 Apr 20
2
Cross-Correlation function (CCF) issues
Dear all, I have two series of returns and I want to find the cross-correlations between these two series. I know of the ccf, but it does not work as I'd like if i type ccf(x,y,lag.max=20,type="correlation",plot=FALSE) i got the error message Error in na.fail.default(ts.intersect(as.ts(x), as.ts(y))) : missing values in object So i found that somebody suggested to type
2009 Aug 12
1
CCF for hourly time series?
Hello, I have a dataframe containing various time series (not time series objects though!)with hourly time steps. I?d like to perform ccf for I need to know the correlation factors for different lags. Here is an example: x<-as.POSIXct(c("2008-12-25 16:00:00", "2008-12-25 17:00:00", "2008-12-25 18:00:00", "2008-12-25 19:00:00", "2008-12-25
2006 Nov 27
2
NaN with ccf() for vector with all same element
hello, i have been using ccf() to look at the correlation between lightning and electrogamnetic data. for the most part it has worked exactly as expected. however, i have come across something that puzzles me a bit: > x <- c(1, 0, 1, 0, 1, 0) > y <- c(0, 0, 0, 0, 0, 0) > ccf(x, x, plot = FALSE) Autocorrelations of series 'X', by lag -4 -3 -2 -1 0
2006 May 19
4
Cross correlation/ bivariate/ mantel
> Background: > OS: Linux Ubuntu Dapper > release: R 2.3.0 > editor: GNU Emacs 21.4.1 > front-end: ESS 5.2.3 > ----------------------------- > Colleagues > I have two spatial datasets (latitude, longitude, fish eggs) and (latitude, longitude, fish larvae) at the same 280 stations (i.e. 280 cases). I want to determine if the 2 datasets are spatially correlated. In other
2011 Jun 30
0
CCF of two time series pre-whitened using ARIMA
Hi all, I have two time series that I would like to correlate but as they are autocorrelated, I am "pre-whitening" them first by fitting ARIMA models, then correlating their residuals....as described in https://onlinecourses.science.psu.edu/stat510/?q=node/75 However, http://www.stat.pitt.edu/stoffer/tsa2/Rissues.htm discusses some issues with ARIMA in R. In particular, for issue 2, if
2012 Aug 08
1
time series, uneven length
I have 4 univariate time series that I believe have correlation between them, I want to create a VAR model between them all. However I have an issue as 3 of them are the same length, however the 4th is smaller. meaning that i cannot use the 4th variable , is there anyway R can get round this issue? > length(tstemp) [1] 746 > length(tspres) [1] 746 > length(tswind) [1] 746 >
2010 Apr 13
0
ccf problem (cross-correlation)
Hi all, I have a problem concerning my understanding of the cross-correlation (ccf) function in R. assume a time serie as: > t<-seq(0,6.28,by=0.01); > my_serie<-ts(sin(t),start=0,end=6.28,deltat=0.01) then I generate an other one shifted by 12 time points: > my_shifted_serie<-ts(sin(t),start=0+0.12,end=6.28+0.12,deltat=0.01) if I do the cross-correlation I get that the two
2008 Apr 23
1
ccf and covariance
Hi. It's my understanding that a cross-correlation function of vectors x and y at lag zero is equivalent to their correlation (or covariance, depending on how the ccf is defined). If this is true, could somebody please explain why I get an inconsistent result between cov() and ccf(type = "covariance"), but a consistent result between cor() and ccf(type = "correlation")? Or
2006 Apr 13
1
How does ccf() really work?
I can't understand the results from cross-correlation function ccf() even though it should be simple. Here's my short example: ********* a<-rnorm(5);b<-rnorm(5) a;b [1] 1.4429135 0.8470067 1.2263730 -1.8159190 -0.6997260 [1] -0.4227674 0.8602645 -0.6810602 -1.4858726 -0.7008563 cc<-ccf(a,b,lag.max=4,type="correlation") cc Autocorrelations of series 'X',
2007 Mar 29
1
ccf time units
Hi, I am using ccf but I could not figure out how to calculate the actual lag in number of periods from the returned results. The documentation for ccf says:"The lag is returned and plotted in units of time". What does "units of time" mean? For example: > x=ldeaths > x1=lag(ldeaths,1) > results=ccf(x,x1) > results Autocorrelations of series 'X', by lag
2006 Sep 15
1
"ccf versus acf"
I am trying to run a cross-correlation using the "ccf()" function. When I select plot = TRUE in the ccf() I get a graph which has ACF on the y-axis, which would suggest that these y-values are the auto-correlation values. How should I adjust the code to produce a plot that provides the cross-correlation values? Here is my code: w002dat <-