2D array?

Hi, I have a 3 by 3 matrix X(a,b,c)

I tried to define a submatrix

S = X(3,:,:);

but matlab keeps saying that S is not a 2D array. Why is that so?

Thank you very much.

Added: class(S) apparently is "double" but I don't understand why. How might I make S into a 2D array?

[Oleg Komarov]

X is a 3D array if you write it in that way: X(a,b,c).

what whos on X returns?

[Werner]

Thank you, @Oleg, but wouldn't S (havin one coordinate fixed), be a 2D array?

[Werner]

@Oleg: Also, if S as defined is not a 2D array, how might I define a 2D array that is essentially the same thing as S? Thanks.

[Walter Roberson]

Werner, X(3,:,:) is a 1 x something x something array. See IA's solution.

Answer 1

[Image Analyst]

Use squeeze(). This works fine for me:

s3D = rand(4,3,2)
s2D = squeeze(s3D(2,:,:))

s3D(:,:,1) =
  0.5103    0.0183    0.1749
  0.6590    0.7794    0.2998
  0.8773    0.6623    0.7778
  0.0790    0.9458    0.6653
s3D(:,:,2) =
  0.2475    0.0516    0.3926
  0.7406    0.1848    0.6212
  0.0042    0.7256    0.4685
  0.5316    0.3404    0.1957
s2D =
  0.6590    0.7406
  0.7794    0.1848
  0.2998    0.6212

You can see that it took row 2 out of the first plane, and row 2 out of the second plane, and gave you a 3 by 2 array, just what it should have.

[Werner]

Thank you !