# Wolfram Language & System 11.0 (2016)|Legacy Documentation

This is documentation for an earlier version of the Wolfram Language.
BUILT-IN WOLFRAM LANGUAGE SYMBOL

# DiskMatrix

DiskMatrix[r]
gives a matrix whose elements are 1 in a disk-shaped region of radius r, and are otherwise 0.

DiskMatrix[r,w]
gives a w×w matrix containing a disk of 1s with radius r.

DiskMatrix[{r1,r2,},]
yields an array whose elements are 1 in an ellipsoidal region with semiaxis ri in the i index direction.

## Details and OptionsDetails and Options

• The disk of 1s is always at the center of the region.
• In DiskMatrix[r] or DiskMatrix[{r1,}] the matrix or array is sized so as to just include all nonzero elements.
• The disk-like region is taken to be the best discrete approximation to a circular disk possible given the size of the matrix.
• DiskMatrix[All,w] gives a w×w matrix containing a disk that is as large as possible.
• DiskMatrix[,{w1,w2,}] gives a w1×w2× array.
• DiskMatrix[{r1,,rn},w] gives a w××w array.
• DiskMatrix[All,{w1,,wn}] gives a w1××wn array containing an ellipsoid that is as large as possible.
• The radius r need not be an integer; in general elements are 1 if their distance from the center is not more than .
• For integer r, DiskMatrix[r] yields a (2r+1)×(2r+1) matrix.

## ExamplesExamplesopen allclose all

### Basic Examples  (1)Basic Examples  (1)

This computes and plots a square disk-shaped matrix of radius 7:

 In[1]:=
 Out[1]=