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Thanks for the replies, everyone. It suppose is not actually that hard for me to handle these dimensions properly -- I just hadn't personally encountered or thought much about when such operations with empty matrices might arise, and was initially puzzled about
what multiplication by an "empty" matrix even means. I think I see now why I need to put in the work to handle these cases properly. (Sure wish that MKL could just do it, though!)<br>
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--Richard<br>
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<div class="moz-cite-prefix">On 5/30/20 4:09 PM, Stefano Zampini wrote:<br>
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<pre class="moz-quote-pre" wrap="">On May 31, 2020, at 1:03 AM, Jed Brown <a class="moz-txt-link-rfc2396E" href="mailto:jed@jedbrown.org"><jed@jedbrown.org></a> wrote:
Stefano Zampini <a class="moz-txt-link-rfc2396E" href="mailto:stefano.zampini@gmail.com"><stefano.zampini@gmail.com></a> writes:
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<pre class="moz-quote-pre" wrap="">If A is 0x8 and B is 8x5 then C is correct to be of size 0x5. The rows and columns of the resulting matrix have to follow the rules.
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Right, I think if you said C is 0x0 (which seems like Richard's proposal), you'd need to relax shape compatibility logic in many places, including in ways that might produce confusing errors.
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Richard
In the triple matrix product case, your code will break, because the operation will no longer be associative
A 3x0, B 0x8, C 8x7 -> (ABC) is a valid 3x7 matrix (empty)
If I understand you right, (AB) would be a 0x0 matrix, and it can no longer be multiplied against C
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<pre class="moz-quote-pre" wrap="">Richard, what is the hardship in preserving the shape relations?
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