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dsax7
dsax7
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I am trying to measure the similarity between two signals and I am using cross-correlation to achieve this.

Following the matlab example, I seem to have accomplished that, however, I do not understand the plot that I am getting. In the matlab example the explanation that is given is: The first subplot indicates that the signal and template 1 are less correlated while the high peak in the second subplot indicates that signal is present in the second template.

My question is how does the peak indicate that the signals have more in common? Shouldn't the two signals be more correlated when the distance between them is lower?

Moreover, when I tried it using my two signals I received the following image: enter image description here which looks more than strange compared to the image from the example, as I have multiple peaks and a relatively long straight line.

EDIT

I added two example signals that yield a relatively same result. As suggested from the comments, I tried without upsampling the signal and making them equal in length, however, the results weren't appealing as well. Furthermore, if the peak is, for example, at the 10s, does this indicate that the signals are simillar at the tenth second? What about if the peaks are in the negative time zone (t<0s)?

I am trying to measure the similarity between two signals and I am using cross-correlation to achieve this.

Following the matlab example, I seem to have accomplished that, however, I do not understand the plot that I am getting. In the matlab example the explanation that is given is: The first subplot indicates that the signal and template 1 are less correlated while the high peak in the second subplot indicates that signal is present in the second template.

My question is how does the peak indicate that the signals have more in common? Shouldn't the two signals be more correlated when the distance between them is lower?

Moreover, when I tried it using my two signals I received the following image: enter image description here which looks more than strange compared to the image from the example, as I have multiple peaks and a relatively long straight line.

I am trying to measure the similarity between two signals and I am using cross-correlation to achieve this.

Following the matlab example, I seem to have accomplished that, however, I do not understand the plot that I am getting. In the matlab example the explanation that is given is: The first subplot indicates that the signal and template 1 are less correlated while the high peak in the second subplot indicates that signal is present in the second template.

My question is how does the peak indicate that the signals have more in common? Shouldn't the two signals be more correlated when the distance between them is lower?

Moreover, when I tried it using my two signals I received the following image: enter image description here which looks more than strange compared to the image from the example, as I have multiple peaks and a relatively long straight line.

EDIT

I added two example signals that yield a relatively same result. As suggested from the comments, I tried without upsampling the signal and making them equal in length, however, the results weren't appealing as well. Furthermore, if the peak is, for example, at the 10s, does this indicate that the signals are simillar at the tenth second? What about if the peaks are in the negative time zone (t<0s)?

Source Link
dsax7
dsax7
  • 271
  • 4
  • 13

Cross-correlation of two signals using matlab

I am trying to measure the similarity between two signals and I am using cross-correlation to achieve this.

Following the matlab example, I seem to have accomplished that, however, I do not understand the plot that I am getting. In the matlab example the explanation that is given is: The first subplot indicates that the signal and template 1 are less correlated while the high peak in the second subplot indicates that signal is present in the second template.

My question is how does the peak indicate that the signals have more in common? Shouldn't the two signals be more correlated when the distance between them is lower?

Moreover, when I tried it using my two signals I received the following image: enter image description here which looks more than strange compared to the image from the example, as I have multiple peaks and a relatively long straight line.