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 ww 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.

Details

  • 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 ww matrix containing a cross shape that is as large as possible.
  • CrossMatrix[,{w1,w2,}] gives a w1w2 array.
  • CrossMatrix[{r1,,rn},w] gives a ww array.
  • CrossMatrix[All,{w1,,wn}] gives a w1wn 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.

Examples

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Basic Examples  (1)

This computes and plots a cross matrix:

In[1]:=
Click for copyable input
Out[1]=

Scope  (5)

Neat Examples  (1)

See Also

DiamondMatrix  DiskMatrix  BoxMatrix  SparseArray  Band  EditDistance  ListConvolve  ImageConvolve

Introduced in 2008
(7.0)