remove global variable 'myThreshold'

[hartig]

@shahrzadkhayatbashi I see that you introduce a global variable called myThreshold in line 45 and then use that global variable in some of the helper functions. That's bad coding style. Please remove this global variable and, instead, pass the threshold as an additional parameter to the functions.

[shahrzadkhayatbashi]

I addressed the global variable issue by removing it and passing it to the calculate function.

[hartig]

The fix that addresses this issue is in commit e3f97c6