Invalid positions can be given in two fashions, with a dep attribute
on positions and then a byte array or with a ref attribute on
positions and an integer list reference the position. DX will
determine which is better when using Include to save more memory. I
have never seen any modules have problems with the type before,
unless someone creates an Invalid Positions component wrong.
David
Recently I ran across some data for which the invalid positions
component array
comes back as integer rather than the byte array that I have been used to. A
"wrong type" error occurs in subsequent modules that utilize invalid positions
(ShowBoundary) if, for example, the 1's are then casted to byte(0). The User's
Guide explains that for a smaller number of invalid positions, in
order to save
memory the array is structured differently (integer indices of only
the invalid
positions, rather than an array of bytes with same dimensions as the data
field).
Is it expected then that a type-check must be made before the
invalid positions
array is altered ? In this particular case I bypassed the problem by removing
the invalid positions rather than manipulating them, but I would like to know
the philosophy behind all this.
.............................................................................
David L. Thompson The University of Montana
mailto:[EMAIL PROTECTED] Computer Science Department
http://www.cs.umt.edu/u/dthompsn Missoula, MT 59812
Work Phone : (406)257-8530
