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+--- Thread: Row vector (multiplication by a column vector) (/thread-19497.html)
Row vector (multiplication by a column vector) - DrD - 02-01-2023 02:21 PM
Example: 3x1 column vector multiplying a 1x3 row vector
a:=[[1,2,3]];
b:=[4,5,6];
a*b => "dotvecteur Error: Invalid dimension"
However, by converting b to a 1x3 matrix first, works.
b:=TRN(TRN(b)); // Converts the 1x3 vector to a 1x3 matrix ...
a*b => [[4,5,6],[8,10,12],[12,15,18]]
Requiring conversion from a row vector to a 1x3 matrix data type is an extra step that could benefit from software improvement, in cases such as these.
RE: Row vector (multiplication by a column vector) - jte - 02-01-2023 09:56 PM
When I took my first linear algebra course, I was taught that vectors are simply special cases of matrices (1×n or n×1, rather than m×n).
RE: Row vector (multiplication by a column vector) - parisse - 02-02-2023 11:16 AM
On the other hand, if you handle this case without error, it will be harder to detect a real error...