Correlation of two signals

How can we perform the correlation of two signals in MATLAB? I know that it can be found using the 'xcorr' function. But in many examples found on the web, the final result of correlation is flipped using the 'fliplr' function. What is the purpose of that? Please help

Answer 1

[Image Analyst]

If you flip the function left to right, then the result is a convolution, not a correlation.

Correlation tells you the sum of the product of the two signals. This will often be a maximum when the two signals are roughly the same shape and are aligned, though not necessarily - a few seconds of thought and you will easily think of some counter examples.