-0f

Community Support
1

Hello All!

I am new to this forum and this is my first question here.

I have been using kdb to develop solutions for my company for about 8 months now.

I have a rather simple question:

q)a:-3i

q)b:0f

q)a*b
-0f

I dont want to see the -0. 

Note that b can be non zero (for example 3), so simply taking the absolute value would not serve my purpose (taking abs would give output as 9, but i want to see -9).

Any help is much appreciated! Thanks a lot.

Giridhar

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2

This might work for you

q){signumabs x}ab

0f

Terry

3

Thanks a lot @TerryLynch

I found another solution by chance:

q)0f+a*b

0f

Just adding 0f seems to work. I don’t have an explanation for this behaviour, but for cleanliness of code I am going with this…

Do you know why this works?

4

Oh nice! Yeah that is cleaner. I don’t know why it works per se, other than that its clear that kdb resolves 0f plus -0f to be 0f. Possibly some edge case logic.

5

https://en.wikipedia.org/wiki/Signed_zero#Arithmetic

6

This is very helpful. Thanks a lot @Charles Skelton