CODEWITHSUNDEEP
fileluanumbersoutput
Nelarius
Nelarius

Reputation: 181

Lua file output: what is -1.#IO?

I'm printing numbers into a file with Lua, and on occasion instead of a number, -1.#IO will be displayed. What does it mean?

The offending code is in the following gist.

https://gist.github.com/Nelarius/6247636

And the offending number is at the very bottom: meanPrice. The value contained is stored in the Commodity table, and the Commodity table later on logs the value into a file.

Upvotes: 3

Views: 4324

Answers (2)

Yu Hao
Yu Hao

Reputation: 122463

On Windows, the floating point number has output of 1.#INF for positive infinity and -1.#INF for negative infinity. The floating point indeterminate number is -1.#IND. But there's no similar representation of -1.#IO.

The most probable reason is, you are outputting numbers with a fixed 3 digits of fraction part. And for 3 digits after the decimal point ., .#INF or .#IND get rounded up to .#IO.

print(-1/0)
print(0/0)
print((string.format("%.3f", -1/0)))
print((string.format("%.3f", 0/0)))

On windows, the output is:

-1.#INF
-1.#IND
-1.#IO
-1.#IO

Upvotes: 6

Alex
Alex

Reputation: 1017

It is, as the commentors say, an invalid number. It should only appear like this on Windows.

See the link below.

Note, the link refers to (-)1.#IND for NaNs and (-)1.#INF for infinity which I get too. I would be interested in what you're doing to generate the #IO.

IEEE Floating point exceptions

Upvotes: 5

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