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When using a DenseMatrix from Math .NET, and I want to access the second column, third row, do I write matrix[1,2] or matrix[2,1] in other words, does the first index determine the row or the column?

Christoph Rüegg
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dmi_
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    matrix[2,1], row first and then the column (syntax is the same as At() method, it follows math standard conventions). – Adriano Repetti Jun 19 '12 at 18:31
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    Thank you both. I could have tested this on my own, and I realize it's easily answered with a test, but I asked the question to spare others the trouble - this is information that should be stated clearly on the web, I believe. – dmi_ Jun 19 '12 at 18:34

1 Answers1

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A quick search yields this documentation:

http://api.mathdotnet.com/Numerics/MathNet.Numerics.LinearAlgebra.Double/DenseMatrix.htm

While it's lacking in what you're asking, it does have a RowCount property you can interrogate to find your answer.

Running a test now

It's [row, column].

public virtual T this[int row, int column]
{
    get
    {
        RangeCheck(row, column);
        return At(row, column);
    }

    set
    {
        RangeCheck(row, column);
        At(row, column, value);
    }
}
Austin Salonen
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