[samigo-team] Floating point numbers

[David Horwitz]

I fixed a very similar problem to this last year, which if I recall Sam reported. A student got 99.99% on a pefect answer - the code was casting to a double not rounding. If I recall this was within SAM and not on the GB export.

D

On Thu, 2013-02-28 at 11:10 +0000, Ward, Lynn E. wrote:
We encountered problems with floating point numbers a few years ago, particularly in assessments containing questions for which the student could earn partial credit.  There were cases where users got all questions correct and received fractionally less than a perfect score.  Rather than replacing floating point numbers throughout, we decided to round assessment scores to 2 decimal places before sending them to the gradebook. Have other institutions had scoring problems as a result of floating point numbers?


Lynn
==========================
Lynn Ward, Principal Systems Analyst

Instructional Technology Systems and Services

University Information Technology Services<http://uits.iu.edu/>
Indiana University
Information Technology and Communications Complex (IT 342K)
535 West Michigan Street, Indianapolis, IN 46202
Phone: 317-278-5713  E-mail: leward at iupui.edu<mailto:leward at iupui.edu>




From: 'Karen Tsao' <ktsao at stanford.edu<mailto:ktsao at stanford.edu>>
Date: Wednesday, February 27, 2013 10:11 PM
To: Sam Ottenhoff <ottenhoff at longsight.com<mailto:ottenhoff at longsight.com>>
Cc: Samigo Team <samigo-team at collab.sakaiproject.org<mailto:samigo-team at collab.sakaiproject.org>>
Subject: Re: [samigo-team] Floating point numbers



Hi Sam,


As usual, we always welcome your patch  :)


But just curious, what is the advantage of this change? Is this for getting a more precise score? Like some 0.999 issue?


Thanks,
Karen

On Wed, Feb 27, 2013 at 9:30 AM, Sam Ottenhoff <ottenhoff at longsight.com<mailto:ottenhoff at longsight.com>> wrote:
Has anyone experimented with completely replacing Samigo's use of single-precision floating point numbers with real numbers (BigDecimal) for scores?


If not, can I assume a patch would be welcomed with open arms?


--Sam

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