logo
down
shadow

How to synchronize signals using a cross-correlation and FFT in R?


How to synchronize signals using a cross-correlation and FFT in R?

By : misanov
Date : November 22 2020, 10:40 AM
To fix the issue you can do The cross-correlation of two complex function equals the convolution of one function and the complex conjugate of the other:
Cross correlation and convolution
code :
convolve(my.vector1, my.vector2)
which.max(convolve(my.vector1,my.vector2))


Share : facebook icon twitter icon
Cross Correlation with Discrete signals

Cross Correlation with Discrete signals


By : CZ云遥
Date : March 29 2020, 07:55 AM
Hope that helps Just do the regular cross correlation. Afterwards set the lags vector accordingly.
Cross-Correlation of two signals

Cross-Correlation of two signals


By : SkyWaiting
Date : March 29 2020, 07:55 AM
To fix the issue you can do You seem to have a slight misunderstanding of how cross-correlation works. Cross-correlation takes one signal, and compares it with shifted versions of another signal. If you recall, the (unnormalized) cross-correlation of two signals is defined as:
code :
s = [0 0 0 0 1 1 1 1 1 0 0 0 0]
h = [1 1 1 1 1 0 0 0 0 0 0 0 0]
s ** h = (0)(1) + (0)(1) + (0)(1) + (0)(1) + (1)(1) + (0)(1) + (0)(1) + (0)(1) + (0)(1) 
       = 1
s = [0 0 0 0 1 1 1 1 1 0 0 0 0]
h = [0 1 1 1 1 1 0 0 0 0 0 0 0]
s ** h = (0)(1) + (0)(1) + (0)(1) + (0)(1) + (1)(1) + (1)(1) + (0)(1) + (0)(1) + (0)(1) 
       = 2
s = [0 0 0 0 1 1 1 1 1 0 0 0 0]
h = [0 0 0 0 1 1 1 1 1 0 0 0 0]
s = [0 0 0 0 1 1 1 1 1 0 0 0 0]
h = [0 0 0 0 0 1 1 1 1 1 0 0 0]
s = [0 0 0 0 1 1 1 1 1 0 0 0 0]
h = [0 0 0 0 0 0 0 0 1 1 1 1 1]
Cross Correlation with signals of different length in MATLAB

Cross Correlation with signals of different length in MATLAB


By : plrnvld
Date : March 29 2020, 07:55 AM
this will help I have 2 signals of different lengths where the shorter signal is the same as the longer n samples shifted. I want to find the maximum normalized cross-correlation between these two signals. Since it is normalized should give 1. The xcorr function lags vary from -441 to 441 samples. , Suppose x and y are the shorter and longer signals you have.
code :
nx = length(x);
ny = length(y);
cc = nan(1,ny-nx+1);
for ii = 0 : ny-nx
  id = (1:nx) + ii;
  cc(ii+1) = sum(x.*y(id))/(sqrt(sum(x.^2)*sum(y(id).^2)));
end
[ccmx,idmx] = max(cc);
Normalizing cross-correlation to [-1,1] for different length signals

Normalizing cross-correlation to [-1,1] for different length signals


By : Megha Jain
Date : March 29 2020, 07:55 AM
I wish did fix the issue. Following the documentation https://it.mathworks.com/help/signal/ref/xcorr.html
There is the Normalization option on xcorr function
code :
[acor,lag] = xcorr(signal1,signal2,'coeff');
Cross correlation / similarity of signals - calculate time lag

Cross correlation / similarity of signals - calculate time lag


By : Nickolass
Date : March 29 2020, 07:55 AM
I think the issue was by ths following , One possible solution to your problem is Mean Squared Error (MSE). Given two signals a and b of same dimensions, MSE is the average value of the element-wise squares of the difference between a and b. The code would look like follows (based on this):
code :
import numpy as np
import matplotlib.pyplot as plt

a = np.array([10, 20, 10, 30, 20, 10, 28, 22, 10])
b = np.array([28, 22])
mse = np.ndarray((len(a) - len(b) + 1))

for i in range(c.size):
    mse[i] = np.square(np.subtract(a[i:i+len(b)],b)).mean()

print(mse.argmin())
plt.plot(mse)
Related Posts Related Posts :
  • Using a loop to find P(-1.5<Y<1.5) for a range of sample sizes
  • R-Count and list the maximum count row by row
  • Include Iverson Bracket in R documentation
  • update a data frame and environment in R
  • How to write dynamic cumulative multiple in R
  • format time using as.POSIX in R
  • Change the class of multiple columns
  • Remove period and spaces within column headings nested in a list of data frames
  • R: error message --- package error: "functionName" not resolved from current namespace
  • labels with geom_text ggplot2
  • Passing mongodb ISODate in R
  • Importing "csv" file with multiple-character separator to R?
  • Change row names of a table obtained from a lm regression using xtable function
  • R language iterate over R object
  • How do you delete the header in a dataframe?
  • Re coding in R using complicated statement
  • accumulating functions and closures in R
  • How do you combine two columns into a new column in a dataframe made of two or more different csv files?
  • Twitter authentication fails
  • Summing Values of One Vector Conditional on Values of Another Vector
  • draw cube into 3D scatterplot in RGL
  • lme4 translate formula to code in 3-level model
  • How to draw single axis plot in R
  • Combine geom_tile() and facet_grid/facet_wrap and remove space between tiles (ggplot2)
  • Use snpStats with R version 3.0.1
  • Makefile gives strange error while compiling markdown file into .docx file
  • How to determine whether a points lies in an ellipse
  • Summarize data already grouped in r
  • Is the bigvis package for R not available for R version 3.0.1?
  • Operator overloading in R reference classes
  • How to enable user to switch between ggplot2 and gVis graphs in R Shiny?
  • Is there an easy way to separate categorical vs continuous variables into two dataset in R
  • Correct previous year by id within R
  • Installation of rdyncall package for R
  • ggplot2 plot that evaluates the percentage and mean of a third variable at intersecting points
  • Error Handling with Lapply
  • data.table - split multiple columns
  • How to compute the overall mean for several files in R?
  • R: Graph Plotting: Subscripts in the legend like LaTeX
  • Restructuring data in R
  • Distance of pointsfrom cluster centers after K means clustering
  • R incorrect value of date function
  • Package "Imports" not loading in R development package
  • r - run a user defined function several times by taking column elements as parameters
  • Create input$selection to subset data AND radiobuttons to choose plot type in Shiny
  • Generate crosstabulations from dataframe of categorical variables in survey
  • Restructure output of R summary function
  • New behavior in data.table? .N / something with `by` (calculate proportion)
  • search certain number vector in R
  • R version doesn't support quartz graphic device - RStudio won't plot
  • Referencing a function parameter in R
  • Plotting coefficients and corresponding confidence intervals
  • passing expressions to curve() within a function
  • More effective merging of matched column with duplicates in data.table
  • Easy way to export multiple data.frame to multiple Excel worksheets
  • R Foreach Iterator - Walkforward
  • Table format and output in R
  • Restructuring data and duplicating rows in R
  • use ggplot2 to plot two lines with ribbons
  • how to plot a graph on lattice with two different colors
  • shadow
    Privacy Policy - Terms - Contact Us © ourworld-yourmove.org