Re: Multicomponent arrays in Blitz++

[Todd V. <tve...@oo...>]

Matthew Weippert wrote:

> Have you checked blitz++ with egcs-1.0.3?

1.0.3 is no good.  See
http://oonumerics.org/blitz/contribute/blitz-dev/archive/0031.html

You need a recent snapshot (egcs-19980615) to compile blitz.  Once
egcs 1.1 comes out, all should be bliss.

> I am a bit confused about multicomponent arrays verses higher
> dimensional arrays.  For example, a multispectral image could be
> represented by a three dimensional array _or_ a two dimensional
> multicomponent array.  (Right?)  What are the differences, trade-offs
> etc?

I would say that a multicomponent array is more powerful.  At
some point I'll provide a "flatten" function which will turn
(for example) Array<RGB24,2> into Array<char,3>.  It's much
harder to go in the reverse direction.  Also, if you have
objects such as RGB24, HSV24, etc. then you can do this:

Array<RGB24,2> A(128,128);
Array<HSV24,2> B(128,128);

B = A;    

And it will convert from RGB24 to HSV24, provided HSV24 has appropriate
conversion methods defined.  Doing this with a 3-dimensional array is
much clumsier.

Cheers,
Todd