How can i extract the value of an element of a sparse double?

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Odin Iversen
Odin Iversen 2020-10-18
评论： Rik 2020-10-18
if i have a sparse duble:
M = zeros(3);
M = sparse(M);
M(3,3) = 2;
and i want to get only the value of M(3,3) = 2, how do i do that?
if i type:
M(3,3)
i get:
ans =
(1,1) 2
but i want to somheow get:
ans =
2
converting to full matrix is not an option since the actual matrix is 50000 x 50000. thank you

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采纳的回答

Bruno Luong
Bruno Luong 2020-10-18
full(M(3,3))

更多回答（2 个）

Rik
Rik 2020-10-18
You can convert the result to a full matrix. Indexing only extracts part of the array, but doesn't influence the sparse property.
  2 个评论
Odin Iversen
Odin Iversen 2020-10-18
so like this:
full(M(3,3))
this only converts that one element to full and not the whole M-matrix in the process?

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Ameer Hamza
Ameer Hamza 2020-10-18
Or maybe this
M(3,3)+0

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