Flatten array without loosing "structure"

[tommasopeduzzi]

Hello

I was wondering if there is a function to turn this matrix

into this matrix

Thanks in advance,
Tommaso

[eric3 (Eric Rimbey)]

You want to look into ArrayReshape.

[tommasopeduzzi]

Thank you for the replies. ArrayReshape did it for me!

[gianlucagorni]

I found this in the documentation for Flatten:

m = {{{{0, 0}, {0, 0}}, {{1, 0}, {0, 1}}}, {{{1, 0}, {0, 1}}, {{0, 
      0}, {0, 0}}}};
m // MatrixForm
Flatten[m, {{1, 3}, {2, 4}}] // MatrixForm

[hdolhaine (Hans Dolhaine)]

Another solution is given here

Inverse of a (m,m)-Matrix whose elements are (n,n)-Matrices

By Albrecht Küster (hcak@gmx.de) and Hans Dolhaine (h.dolhaine@gmx.de) In a foregoing post https : // community.wolfram.com/groups/-/m/t/1651695?p_p _auth = EmJqMz34 Stan Gianzero asked, how the inverse of a 2 x 2 matrix, whose elements are 2 x 2 matrices themselves might be found. In that post an answer was given and Stan's problem solved. But this anwer is highly specialized, because all the elements of the given matrix must be regular ( = non-singular) and moreover certain functions o…

wcomABdivmat.nb (367 KB)

[mroge02 (Michael Rogers)]

ArrayFlatten[a] also works.