Toronto Math Forum

APM346-2012 => APM346 Misc => Topic started by: Ian Kivlichan on December 21, 2012, 02:15:04 PM

Title: Bug in HA total calculation?
Post by: Ian Kivlichan on December 21, 2012, 02:15:04 PM
I think there might be some bug with the total homework mark calculation mentioned in this post ( http://forum.math.toronto.edu/index.php?topic=162.msg987#msg987 ).

Calculating my total homework mark using the same formula, I get a total HA mark 2 points greater than the one I see online on Portal. Does anyone else have a similar issue? I wonder if it might affect people who did not submit HA9 in particular, since I did not submit it, and know of someone else who did not submit it who seemed to have the same problem.

Cheers,

Ian
Title: Re: Bug in HA total calculation?
Post by: Victor Ivrii on December 21, 2012, 05:19:13 PM
Ian, thanks for alerting!

There really was a bug albeit not exactly one you thought. It appears that functions
Code: [Select]
SMALL(E2:M2,1), SMALL(E2:M2,2) were stupid enough to skip empty cells. So for a student who had, say, '-,-,19,18,20,20,20,20,13' these functions had dropped not '-,-' but '13,18'.

There was no problem with HA9 as it was rescaled and those who missed it had '0' in the calculations rather than'-' but with any other missed homework. I solved this by temporarily creating columns which were copies of those corresponding to HA1:HA8 but with '-' replaced by '0' and using them to calculate total.

I recalculated marks and uploaded them.

Everyone who was affected should thank Ian



I hate spreadsheets, Microsoft and Blackboard!!!!