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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
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<TITLE>SPEYE Sparse Identity Matrix
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<H2>SPEYE Sparse Identity Matrix
</H2>
<P>
Section: <A HREF=sec_sparse.html> Sparse Matrix Support </A>
<H3>Usage</H3>
Creates a sparse identity matrix of the given size. The syntax for
its use is
<PRE>
y = speye(m,n)
</PRE>
<P>
which forms an <code>m x n</code> sparse matrix with ones on the main diagonal,
or
<PRE>
y = speye(n)
</PRE>
<P>
which forms an <code>n x n</code> sparse matrix with ones on the main diagonal. The
matrix type is a <code>float</code> single precision matrix.
<H3>Example</H3>
The following creates a 5000 by 5000 identity matrix, which would be
difficult to do using <code>sparse(eye(5000))</code> because of the large amount
of intermediate storage required.
<PRE>
--> I = speye(5000);
--> which I
Function I is unknown!
--> full(I(1:10,1:10))
ans =
1 0 0 0 0 0 0 0 0 0
0 1 0 0 0 0 0 0 0 0
0 0 1 0 0 0 0 0 0 0
0 0 0 1 0 0 0 0 0 0
0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0
0 0 0 0 0 0 1 0 0 0
0 0 0 0 0 0 0 1 0 0
0 0 0 0 0 0 0 0 1 0
0 0 0 0 0 0 0 0 0 1
</PRE>
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