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    <p>The article seems to point out different ways to represent matrix data structures and the performance gains of a single array representation, although it doesn't really explain why you get the performance gains.</p> <p>For example, to represent a NxNxN matrix:</p> <p>In object form:</p> <pre><code>Cell { int x,y,z; } Matrix { int size = 10; Cell[] cells = new Cell[size]; } </code></pre> <p>In three-arrays form:</p> <pre><code>Matrix { int size = 10; int[][][] data = new int[size][size][size]; } </code></pre> <p>In a single array:</p> <pre><code>Matrx { int size = 10; int[] data = new int[size*size*size]; } </code></pre> <p>To your question, there is a performance gain by representing a NxN matrix as a single array of N*N length, you gain performance because of caching (assuming you cannot fit the entire matrix in one chunk); a single array representation guarantees the entire matrix will be in a contiguous chunk of memory. When data is moved from memory into cache (or disk into memory), it is moved in chunks, you sometimes grabs more data than you need. The extra data you grab contains the area surrounding the data you need.</p> <p>Say, you are processing the matrix row by row. When getting new data, the OS can grab N+10 items per chunk. In the NxN case, the extra data (+10) <em>may</em> be unrelated data. In the case of a N*N length array, the extra data (+10) is most likely from the matrix.</p> <p>This article from SGI seems to give a bit more detail, specifically the Principles of Good Cache Use: <a href="http://techpubs.sgi.com/library/dynaweb_docs/0640/SGI_Developer/books/OrOn2_PfTune/sgi_html/ch06.html" rel="nofollow">http://techpubs.sgi.com/library/dynaweb_docs/0640/SGI_Developer/books/OrOn2_PfTune/sgi_html/ch06.html</a></p>
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    1. POHow does an N dimensional array with c-dimensional objects perform differently from an N dimensional array with C objects?
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    1. POHow does an N dimensional array with c-dimensional objects perform differently from an N dimensional array with C objects?
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    1. COFor bonus points : What about the different use of different types for different dimensions?
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    2. CO@peter_gent What do you mean? Specifically the use CV32FC1, CV32FC2, or CV32FC3?
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    3. COI believe these are types specified in the text? Why would you use these different types?
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