I normally see that from engineers using "O(x)" as "approximately x" whenever it's clear from context that you're not actually talking about asymptomatic complexity.

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jcgrillo 4 hours ago | parent [-]

I've always thought it was like this, maybe I'm wrong:

O(some constant) -- "nearby" that constant (maybe "order of magnitude" or whatever is contextually convenient)

O(some parameter) -- denotes the asymptotic behavior of some parametrized process

O(some variable representing a small number) -- denotes the negligible part of something that you're deciding you don't have to care about--error terms with exponent larger than 2 for example

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wizzwizz4 4 hours ago | parent [-]

Those last two notations are, formally, the same. To call a part negligible, we say it's asymptotically bounded above by a constant multiple of this expression, which obviously goes away as we approach the limit. The first one is a colloquial alternative definition that would probably be considered "wrong" in formal writing.

	▲	jcgrillo 4 hours ago \| parent [-]
		Agreed