Joel,
As the error indicates, fprintf() does not accept cell inputs. The conn variable is a 1x1 cell while the other inputs are strings.
You can make "conn" a string by extracting the cell contents instead of setting conn equal to a 1x1 cell.
Just change:
conn = Connect(r);
Into:
conn = Connect{r};
The curly braces indicate content extraction from the r'th cell of Connect instead of assigning conn to the r'th cell itself.
Hope this helps.
