• Andrew <andrew.spott gmail.com> May 29 2009
• bearophile <bearophileHUGS lycos.com> May 30 2009

Andrew <andrew.spott gmail.com> writes:

So, how do I take a cross section of a 3-D array.  Basically I want to be able
to take a 2D matrix from a 3-D array.

auto m = a[][n][];

something like that.  Any ideas?

if you need more info, let me know.

-Andrew

bearophile <bearophileHUGS lycos.com> writes:

Andrew:
 So, how do I take a cross section of a 3-D array.  Basically I want to be able
to take a 2D matrix from a 3-D array.
 auto m = a[][n][];


Languages (or libraries) like matlab and NumPy allow to slice nD arrays like
you say, using a very compact syntax, but currently the D1/D2 languages aren't
designed for people that perform "serious" numerical computations, so it
doesn't offer built-in ways to slice nD arrays.
So you can write a function template that performs such slices, that insides
copies items.

Currently D1/D2 1D arrays are 2-structs that point to a memory zone, so 2D
arrays are 2-structs that contain a pointer to a memory zone of structs that
contain pointers to memory zones of the "rows" of data.

Bye,
bearophile