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CrossMatrix

CrossMatrix[r]
gives a matrix whose elements are 1 in a centered cross-shaped region that extends r positions along each index direction, and are 0 otherwise.
CrossMatrix[r, w]
gives a w×w matrix containing a cross-shaped region of 1s.
CrossMatrix[{r1, r2, ...}, ...]
yields an array whose elements are 1 in a centered cross-shaped region that extends ri positions in the i^(th) index direction.
  • The cross of 1s is always at the center of the region.
  • In CrossMatrix[r] or CrossMatrix[{r1, ...}] the matrix or array is sized so as to just include all nonzero elements.
  • CrossMatrix[All, w] gives a w×w matrix containing a cross shape that is as large as possible.
  • CrossMatrix[..., {w1, w2, ...}] gives a w1×w2×... array.
  • CrossMatrix[All, {w1, ..., wn}] gives a w1×...×wn array containing a cross-shaped region that is as large as possible.
  • Elements of CrossMatrix[r] are 1 if their edit distance from the center is not more than 1.
  • The parameter r need not be an integer; in an odd-dimensional array, the cross extends Floor[Abs[r+1/2]] pixels from the origin.
  • The lines of the cross have width 1 if the corresponding dimension is odd and width 2 otherwise.
  • For integer r, CrossMatrix[r] yields a (2r+1)×(2r+1) matrix.
This computes and plots a 3 by 3 cross matrix:
This computes and plots a 3 by 3 cross matrix:
In[1]:=
Click for copyable input
Out[1]=
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