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Discussion on: ML Fundamentals in Javascript

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swatirajan7 profile image
Swati Rajan

Great article! I had no idea about math.eval() Can we apply them to matrices too?

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mrinasugosh profile image
Mrinalini Sugosh (Mrina) Author

@swatirajan7 Glad you found it useful! Yes it can...For instance, it can be used to extract a subset of a Matrix by range indices. For example, this snippet returns the first and second column of Matrix A (indices start with 1) with all their rows as two vectors in a new matrix.

let matAsub = math.eval('matA[:, 1:2]', { matA });
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Mrinalini Sugosh (Mrina) Author

Actually, I would even propose taking it a step further and assign columns in a matrix to a new vector:

math.eval(`matA[:, 1] = vectorB`, { matA, vectorB });
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