Bug in Class() Function

[syahfira]

Hi. I have found a bug with the QS Class() function.

The bug is about the some numbers are not falling into its class itself.

For example : 0.3, 0.6, 0.7.

Please find tables I have created in QVF attached  for reference.

But, for other numbers, it fall perfectly on its respective interval. Hence, this is consider as bug?

Please correct me if am wrong.

Thank you 😍

[sunny_talwar]

The app attached is without data loaded into it... and we can't reload because we don't have the source... can you provide the source file or the app with data loaded into it

[syahfira]

Hi Sunny, sorry for the previous attachment.
I have attached the correct qvf file.
Thank you.

[tresesco · Accepted solution]

Hi,

This seems to be a NOT bug, but a known issue for floating point comparison for equality. Decimal numbers can't be precisely represented in binary format. Therefore, comparing decimals for equality in binary is unsafe. And in your sample test you must have noticed the bug (you noticed) is exactly where the check is for equality. 

For better understanding you might want to have look at the very well-thought writing here :https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/ 

[syahfira]

Hi Tresesco, thanks so much for the reply. Now, I understand about these floating points. 

Managed to make the class() function work for my set analysis.

 

[tresesco]

Good to know. Please close the thread by giving 'Like' and/or choosing as correct answer.