I am unsure of the correct (general) term for the output of a matrix multiplication?

I have looked at:

  • multiple
  • matrix multiple
  • matrix product

If $C=AB$, then $C$ is the product of $A$ and $B$.

This hold in general, not only for matrices: The result of a multiplication is called a product. Just like the result of an addition is called a sum.

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    $\begingroup$ Wikipedia is clear about this. $\endgroup$ – lhf Aug 1 at 14:06
  • $\begingroup$ @Inf thanks! Wiki also says "The result matrix, known as the matrix product, has the number of rows of the first and the number of columns of the second matrix". Do you think it's better to use that term, e.g. since it more specific, as in, it gently disambiguates between a multiple (of any two structures, e.g. two integers), and those strictly of matrices? Can 'matrix product' be okay too? $\endgroup$ – stevec Aug 1 at 14:10
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    $\begingroup$ @stevec Only if it helps make the sentence clearer. You would, for example, say "Let $C$ be the product of an upper-triangular matrix $A$ and a lower-triangular matrix $B$...". You certainly won't be tempted to correct it as "Let $C$ be the matrix product..." - it would sound as unnecessary repetition, as the context is clear. $\endgroup$ – Stinking Bishop Aug 1 at 14:50
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    $\begingroup$ Of course, if you mean the other, more rarely used, component-wise matrix product (Hadamard's product), that is unusual and needs to be pointed out. (en.m.wikipedia.org/wiki/Hadamard_product_(matrices) ) $\endgroup$ – Stinking Bishop Aug 1 at 14:56
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    $\begingroup$ @stevec Fully agree. You are multiplying data frames (which seems to be some sort of tables, I am no expert in R), so it does need to be pointed out that they are multiplied as matrices. $\endgroup$ – Stinking Bishop Aug 2 at 8:04

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