Boyko Bantchev wrote: > Sorry, I really haven't read the examples so far, and > groking the definition of u . v as written in J is beyond > my abilities. > > As for the text from the dictionary, I concluded that the > said generalization is only w.r.t. u and v. > I do not believe it suggests generalizing towards non-square > matrices, as it speaks of `minors', and the only minors I > know of are determinants (i.e., pertain to square matrices).
The text of the dictionary provides a definition for minors which does not require square matrices: minors=: }."1 @ (1&([\.)) Even if you don't know enough J to read that expression, (perhaps you are not familiar with \.) you could examine what it does on arrays of indices. For example, consider the results of (;$)minors i. 2 2 (;$)minors i. 3 3 (;$)minors i. 4 3 etc. -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
