I’m working on a program (attached) that uses the centroid of a set of points in 3D. In the function “centroid[list, n], if centroid[] is spelled properly, the function produces output that indicates the list is not being properly accessed. I left a copy of this output in the file. Print statements were inserted to display the problem. If I spell the function “centroyd[]”, it works as intended. I am using MMA 10.0.0 on a 2009 iMac running OSX 10.9.3 with 16 GB ram. When the problem occurred, I had only Firefox open in addition to MMA. Any ideas? Is the bug in MMA or in my head?

I noticed that my first attachment accidentally included some unnecessary graphics and additional programming, so I replaced it with the current version. If you downloaded the first one, please discard it to avoid confusion. My apologies.