Summation not equal

[Chuan]

See attached VI, can anyone explain why this weird thing happens:

I extracted the 1st element of waveform and changed it to a control, I tested it is equal to the 1st element in the waveform. And then I do a summation using the 1st element in the waveform and controls, they are not equal?

[GerdW · Accepted solution]

Hi Chuan,

they are not equal?

Do you know the difference between SGL and DBL datatypes?

If you know then I wonder about your question.

I not, then you should learn about it!

I extracted the 1st element of waveform and changed it to a control,

You forgot to note you also changed its representation…

General lesson learned (again after all those threads on the very same problem): NEVER compare floats for equality!