So I've used the "unit impulse" (which is a 1.0 magnitude sample followed by zeros) to test filters, and a "unit step" (50% of the samples are 0, the remaining 50% are 1.0) to test stability. But what does one call the signal which is (1.0, -1.0, 0.0, ...) ? I've been calling it the 'glitch' test. The FFT looks like an inverted bowl. But I'm wondering if it has a name.

--Chuck

The impulse is like Dirac's delta function, a single zero crossing is a first derivative of the delta function, and more crossings are higher derivatives. So a name like "impulse prime" and "impulse double prime" would make sense (at least to physicists, not sure about mathematicians). Plus it's not a tongue twister!

I like that, impulse prime. I'll use that name in my code, thanks!

Hi ChuckMcM,

We need to coin a name for it. "inverted bowl" sounds right to me.

The problem is then we need to be fair to other patterns such as [-1,+1,-1, zeros] and we can call it inverted bowl second degree and so on. But do you see any significance of these patterns for checking dsp functionality or implementation.