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Is there any name for following averaging equation and how does it work?

$$ y_{i+1} = (1-\alpha)\times y_i + x_i $$

I'm using it to average a signal, but I'm not sure am I interpreting the results right.

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Can you describe why you need to average this signal? Do you mean that you're smoothing a signal? – littleO Oct 31 '12 at 9:49
What is $x_i$ and what is $y_i$? – malin Oct 31 '12 at 10:06
$x_i$ is a sample from signal. $y_i$ is a previously value of averaged $y$ and $y_{i+1}$ is next averaged value from $y$. @littleO No, I'm not smoothing a signal, so I'm not looking for a averaging filter. I just should see that when the signal values get stronger $y_i$ should get stronger also. So it should be able to detect changes in signals strength. – gillian Oct 31 '12 at 10:37

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