Matrix blocked question

help
1

Hello !

I have the following question: if i have a NXN matrix ([[f32; MAX]; MAX]) that is ordered by blocks, for example BLOCK_SIZE = 64. How can i get the blocks ? If i do:

matrix.windows(BLOCK_SIZE)

[ [0, 1, 2, 3, 4]
  [5, 6, 7, 8]
  [9, 10, 11, 12]
  [13, 14, 15, 16]
]

if I do:
matrix.windows(2)
it gives me:
[
[0, 1, 2, 3, 4]
[5, 6, 7, 8]
]
[
[5, 6, 7, 8] ]
[9, 10, 11, 12]
]
[
[9, 10, 11, 12]
[13, 14, 15, 16]
]

but i need

[
  [0, 1, 2, 3, 4]
  [5, 6, 7, 8]
]
[
  [9, 10, 11, 12]
  [13, 14, 15, 16]
]

Any suggestions ? Thank you very much !

2

If you want to get the 2D blocks which your matrix is made out of, you'll need to make a custom iterator for that probably.

Note however that you can't return a & [mut] [& [mut] [f32]] since that would imply the references live somewhere but iterators can't return references to their own belongings.

3

My problem is that

matrix.windows(BLOCK_SIZE)

it returns a the same last elements. Here is an example:

[ [0, 1, 2, 3, 4]
  [5, 6, 7, 8]
  [9, 10, 11, 12]
  [13, 14, 15, 16]
]

if I do:
matrix.windows(2)
it gives me:
[
[0, 1, 2, 3, 4]
[5, 6, 7, 8]
]
[
[5, 6, 7, 8] ]
[9, 10, 11, 12]
]
[
[9, 10, 11, 12]
[13, 14, 15, 16]
]

but i need

[
  [0, 1, 2, 3, 4]
  [5, 6, 7, 8]
]
[
  [9, 10, 11, 12]
  [13, 14, 15, 16]
]

Any ideas ? Thanks

4

You want chunks or chunks_exact they don't overlap where windows does.

5

Thank you so much !

6

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