Information Technology Reference
In-Depth Information
17. Fuzzy math
You might think that the way government balances the budget - yeah, right - is an
example of fuzzy math. Maybe that's true, but not what I had in mind here. A few years
ago when I was a computer programmer, I got a request from a user for a report dealing
with percentages. The specifics of the report are a blur since it was some time ago but the
assignment created some difficulties that were not easily resolved. I can relate that
occasion by a very pertinent report today. Suppose I want a report on usage on web sites,
along with percentages. The access to a site will result in a hit and assuming the sites are
Chris, Kelly, Pat, Rene, Whitney and Jamie, the report might look like the following:
WEB SITE ACCESS REPORT
site name
hits
percentage
Chris
0
0%
Kelly
0
0%
Pat
1
33%
Rene
0
0%
Whitney
2
67%
Jamie
0
0%
________________________________________
totals
3
100%
The report looks simple enough but suppose our computer did not round results as
we see here. The 67% percentage for the Whitney site would then be only 66% and the
sum of the percentages would be 99% and not 100%. Assuming we do take into
consideration rounding - either we provide for it in our program or the computer handles
it - suppose a week later we ran the report and got the following:
