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Questions tagged [cross-correlation]

A measure of correlation between different time series, at the same or different times.

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1answer
8k views

Correlation between two 2D arrays

I could not find anywhere, how to calculate correlation between two arrays. Say I do have Array1 with X and Y values and also Array2 with X and Y values. I tried to do some calculation and inserting ...
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2answers
172 views

Correlation between spatial distributions

I have three bivariate data sets of different sizes and the same sampling interval. These represent the variation of dry river bed direction with distance at equidistant sample points. When plotted ...
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0answers
535 views

Cross correlation of gaussian signals with its mean signal gives non-gaussian distributed scores

The following is my question: I have signals that contains noise, they are of the following form see the figure below.. Then I take the mean signal of all these signals (identical in length and shape)....
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1answer
684 views

Cross-correlation with Spearman's method

I am trying to calculate the cross-correlation between two time series. I know that ccf in R base can slove this problem and it uses Pearson's correlation method. My question is: How can I calculate ...
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1answer
33 views

Compare two distributions with varying focus on different regions

I have been trying to find if my problem matches has been discussed in prior research and if any technique exists to solve it. Here's the problem: Given two distributions (pdf) D1 and D2 over a ...
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0answers
93 views

How can the Cross-correlation of two time series be used to measure similarity between vectors

Because cross correlation methods (like numpy.correlate) typically return vectors, how can they be used to determine the similarity of two input vectors
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0answers
232 views

Cross correlation function in more than one dimension

The cross correlation function is $CCF(\tau) = \int f(t)g(t+\tau)dt$ My question: are there any extensions to higher dimensional spaces? For instance, assuming space dimension $x$ is orthogonal to ...
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0answers
43 views

Correlate incidence rate with number of cases

As title says, I want to see how well incidence rate (over a period of years) of a disease compares with number of cases of a certain procedure (over the same period of years) used to cure it. How ...
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1answer
3k views

Pearson correlation coefficient for lagged time series

I am trying to calculate lagged Pearson correlation coefficient between time series. I am not interested in calculating cross-correlation. I want to calculate Pearson correlation coefficient because I ...
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2answers
7k views

How do I interpret this cross correlation function (CCF) plot?

I am working on some exchange rates data. I have two series: $X_t$ with the official exchange rate (e.g. forex) $Y_t$ with the exchange rate on the "black market" (e.g. currency exchange houses at ...
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0answers
97 views

Distribution of two correlated multivariate normal distributions

Let $\varepsilon_{s}^{FR}$ follow a Gaussian Markov process so that ${\varepsilon_{s}^{FR} = \rho \varepsilon_{s-1}^{FR} + \xi_{s}^{FR}, \: \xi_{s}^{FR} \sim \mathrm{i.i.d.} \: N(0,\sigma^{2}_{\xi^{...
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1answer
101 views

Deriving the single factor model

Consider the following regressions: $y_1 = \beta_1 \cdot x + \gamma_1 \cdot \epsilon_1 $ $y_2 = \beta_2 \cdot x + \gamma_2 \cdot \epsilon_2 $ With $\epsilon_1$, $\epsilon_2 \tilde{} N(0,1) $ as ...
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1answer
666 views

Which test statistic to use to test for cross-sectional dependence in panel data (R, plm)?

I would like to test for cross-sectionally dependent residuals in my panelmodel (pooled). I found pcdtest() in plm package and tried ...
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1answer
907 views

Cross-correlation of two autocorrelated signals (removing autocorrelation with ARIMA)

I want to get the cross-correlation of two time series x and y in R. I have calculated an ARIMA model, and I can get the ...
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3answers
2k views

Cross-correlation between two seasonal series

To determine cross-correlation between Sales and Variable cost, both having monthly seasonality, do I need to de-seasonalize ...
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1answer
604 views

How to test if I can use cross-correlation?

I want to compare two time series in R and see if they are cross-correlated (with ccf). I believe that they have to be stationary? How that my data is stationary in R and are there any other ...
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1answer
360 views

Cross-correlation gives autocorrelation in R?

I am not very familiar with cross-correlation analysis. I am analysing a large number of "paired" time series. For each pair, I am doing a ccf in R. I read in other posts that the horizontal line ...
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2answers
2k views

Testing significance of cross-correlated series

I want to prove that, overall, signal B is correlated to signal A. I was thinking of using cross-correlation (in R) to measure this. Essentially I have two kinds of signals: signal A is a series of ...
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1answer
3k views

Cross Correlation and Prewhitening

I am using cross correlation to demonstrate a potential link between two time series (ext & co). Both series are strongly autocorrelated, so it is difficult to assess the dependence between the ...
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0answers
750 views

Cross correlation between 2 filtered time series

I have 2 band pass filtered time series for 30-90 day band I would like to understand the lagged correlation between these 2 series in this band. The issue is that autocorrelations exist in both ...
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1answer
554 views

Detrended Cross Correlation in R

I am looking at determining the relationship between two non-stationary time series, i.e. monthly cost and sales for a period of ...
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0answers
135 views

Finding causality and cross correlation of multiple variables in time series

I'm new to time series. I have 24 variables in a monthly measured time series from 2009 to 2015. The time series measures how much production data that is registered in a ERP system and are ...
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0answers
295 views

Two variables correlated to a third one but not together

Let's consider the following correlation matrix: $$\begin{pmatrix} 1 & 1 & 1 \\ 1 & 1 & 0 \\ 1 & 0 & 1 \end{pmatrix}$$ which describes the correlation between 3 random ...
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3answers
173 views

How to detect inversions in the behavior of two time series through an online algorithm?

I would like to know if there is any technique which is capable to detect online (i.e. considering a sliding window) if there is a correlation between two time series. In particular, I'm trying to ...
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0answers
109 views

Compare if a time series is more correlated to the time series in a group than to the time series in another group?

Given a time series $T_0$, group 1 of time series $T_{1,1},...,T_{1,n_1}$ group 2 of time series $T_{2,1},...,T_{2,n_2}$, ... group m of time series $T_{m,1},...,T_{m,n_m}$, what are some ways to ...
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1answer
748 views

Correlation as a time series

I have been studying a few simple statistical models for (univariate) time series. From my understanding, ARIMA and its siblings are used to model the mean of a time series. Rather than a static ...
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0answers
152 views

Cross-validated cross-correlation

I am trying to build a regression model for the forecast of stock market returns. The regression takes about 100 variables as input and my training data consists of n=234 weekly data points. I am ...
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0answers
500 views

Multiple Cross-correlation

I'm trying to compare two sets of time series. I've successfully used cross-correlation to compare two series between them, but I'm not sure about the way to go for several series. Let me be more ...
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0answers
124 views

chicken egg problem

I should run a test to determine whether variable A affect variable B or viceversa. What type of test should I use? Imagine that we measure the time slept per night (A) and the activity performed ...
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1answer
254 views

Quantification of the extent of periodicity in a time series using fractal analyses

I need metrics to quantify the extent of periodicity between of a time series (for comparison with other time series), considering the time series is almost periodic. By almost periodic I mean: if I ...
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1answer
126 views

What type of analysis to choose for this data?

I am trying to create a model of refrigeration having the energy consumption and the temperature over time. So far, I've tried regression but fitting this data into linear model seems impossible. ...
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1answer
2k views

Spatial cross-correlation: What is the correlation statistic used by the correlog function?

I want to look at the spatial cross-correlation between 2 variables. I am currently using the function correlog from the package ...
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3answers
653 views

Help w/ finding correlation between unemployment rate and home prices over the same time period?

I am interested in analyzing the correlation between nationwide home prices and nationwide unemployment rates, both of which are leading economic indicators. I have data on nationwide home prices by ...
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2answers
1k views

Cross correlation influenced by self auto correlation

I have two stationary time series ts1, ts2, I wanna find the cross correlation ($\textrm{CCF}$) between them. As a result, it ...
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0answers
42 views

Consistent estimate vs out-of-sample performance

When there is a cross-correlation structure in linear regression errors, the usual approach is to model the errors as an ARIMA process. It leads to a consistent estimate of the parameters of the model....
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3answers
126 views

Variance of average due to correlation between auto-correlated time series

I want to calculate the average value of $n_i$ time series each of length $n_t$, i.e. an average of $n_i \times n_t$ values, together with a measure of uncertainty. To be more concrete, I have $n_i\...
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0answers
1k views

Cross- correlation between two non-stationary time series

I have two time series that are growing together. I want to measure if these series are growing similarly together with some lag. Originally, I was thinking I would just take the cross-correlation ...
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1answer
59 views

Event data correlation

I have two sets of data from two different types of sensor. For each instance a sensors output exceeds a threshold the amplitude and time is it is logged as an event. Thus each event consists of a ...
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0answers
77 views

cross correlation of partially correlated signals

I measure $x(t)$ and $y(t)$, two stationary random signals, and I want to find out if, and how much, they are correlated. What I'm doing is to plot the cross correlation ...
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3answers
2k views

Do we need to detrend when do Cross-Correlation between two time series?

I have a group of time series variables and I want to found out the relationship among them. The method I use is to calculate pair-wise correlation between two time series and found out those with ...
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3answers
5k views

What algorithm can I use to find correlations between events?

I am new to machine learning so I am trying to find some literature but I'm not even sure what to Google for. My data is of the following form: ...
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0answers
95 views

Does possible autocorrelation in data affect simple correlations?

I have a question concerning autocorrelation in data affecting correlation coefficients. Consider a time series of stock returns (e.g. 10 trading days) of different stock markets (A, B, C and D) and I ...
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1answer
89 views

Help needed with correlating two datasets

First cross-validated question so please be gentle :o) I have two datasets all gathered and managed in 'R'... Dataset 1 - News Corpus. Contains 3,270 entries from the period 1/Apr/13 to 31/Mar/14. ...
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0answers
267 views

CCF time lag in minutes in R

I have data sampled every 5m and I want to estimate the ccf between them, in order to do it I prewhiten the time series x and y and then I apply CCF But lags are not direct related with my sampling ...
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1answer
369 views

How to calculate the cross correlation between two time series measured at different instants?

I have two time series with measurements of the same type but different stations. I would like to know if the two series are correlated and how much is the "lag" between them. The idea is that in this ...
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1answer
615 views

Calculate correlation between events and signals in time series

I have a time series signal (continuous values) and some events occurring. An event for me is characterized by the fact that it only has a single timestamp assigned to it and not a timespan. Is there ...
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0answers
146 views

Analysing the correlation between two trends

I've got 2 growing trends. One is the input (the number of published articles on a website) and I want to understand if the other appears to be correlated (the number of daily visitors). The problem ...
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1answer
2k views

Code for detrended cross-correlation in R

I want to code for Detrended Cross Correlation in R for time-series data but I'm still stuck. I don't know why the coefficient is not in range -1 : 1. I try to write following these equation below ...
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1answer
609 views

What are good values for autocorrelation, Gelman, and cross-correlation in rjags?

I don't want to post my whole code since it is long, so I will only post part of it: ...
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1answer
893 views

R Own Implementation of Cross Correlation using Convolution

I try to implement my own cross correlation function in R by translating it as a convolution problem. Part I: So I have two arrays, e.g. two identical arrays, and I want to get the cross correlation ...