How to convert multidimensional matrix into regular matrix?

Question

I have this multidimensional matrix:

{{{{a1, a2}, {a3, a4}}, {{b1, b2}, {b3, b4}}}, {{{c1, c2}, {c3, c4}}, {{d1, d2}, {d3, d4}}}}

I would like to convert it into this regular matrix:

{{a1, a2, b1, b2}, {a3, a4, b3, b4}, {c1, c2, d1, d2}, {c3, c4, d3, d4}}

I have tried to use Flatten and Partition, but then I get this result:

{{a1, a2, a3, a4}, {b1, b2, b3, b4}, {c1, c2, c3, c4}, {d1, d2, d3, d4}}

Thanks in advance :-)

score 4 · Answer 1 · answered Mar 14 '14 at 20:10

4

You can use ArrayFlatten for this:

ArrayFlatten[{{{{a1, a2}, {a3, a4}}, {{b1, b2}, {b3, b4}}},
              {{{c1, c2}, {c3, c4}}, {{d1, d2}, {d3, d4}}}}]

(* {{a1, a2, b1, b2}, {a3, a4, b3, b4}, {c1, c2, d1, d2}, {c3, c4, d3, d4}} *)

answered Mar 14 '14 at 20:10

Simon Woods

84,945
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IMHO this is the correct answer. +1 – Mr.Wizard Mar 16 '14 at 13:54

score 3 · Accepted Answer · edited Apr 13 '17 at 12:55

3

Here is what you need:

Flatten[
   {
      {{{a1, a2}, {a3, a4}}, {{b1, b2}, {b3, b4}}}, 
      {{{c1, c2}, {c3, c4}}, {{d1, d2}, {d3, d4}}}
   }
   , 
   {{1, 3}, {2, 4}}
]

Have a look here for an explanation.

edited Apr 13 '17 at 12:55

Community

1

answered Mar 14 '14 at 15:49

Leonid Shifrin

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How to convert multidimensional matrix into regular matrix?

2 Answers2