Thanks David and everyone else. I did search the forums and wiki but struck out. It wasn't clear to me at first how identity matrix related. I was searching for "diagonal", which was found on the page, but didn't produce the result I was looking for. I'll have to study the page and learn more of the concepts.
J's body of documentation and addons is a huge advantage over other languages for me. I can't understand the notation on Wikipedia sometimes The executable and clear notation of J is great as I dig into math concepts. I appreciate the extra solutions. It's more to learn from. On Thu, Feb 27, 2014 at 7:09 AM, David Lambert <[email protected]> wrote: > You've already gotten several solutions. This is a good time to learn of > the j essays. > > http://www.jsoftware.com/jwiki/Essays/Identity%20Matrix > > >>Date: Wed, 26 Feb 2014 22:02:00 -0500 >>From: Joe Bogner <[email protected]> >>To: [email protected] >>Subject: [Jprogramming] create matrix from diagonal >>Message-ID: >> <caetzv1z8cc0sk52_r-bg9nuqch4vo8suuzzpjsg0m1s5nuh...@mail.gmail.com> >>Content-Type: text/plain; charset=ISO-8859-1 > >> >>I'm experimenting with svd and am looking for a nicer way of creating >>a matrix from the S diagonal >> >>4 3 2.23607 0 >> >>needs to be >> >>] (4 4 $ 4 0 0 0 0 3 0 0 0 0 2.23607 0 0 0 0 0 ) >>4 0 0 0 >>0 3 0 0 >>0 0 2.23607 0 >>0 0 0 0 >> >>What would be the idiomatic way to make that conversion? I tried >>various versions of reshape and insert. >> >>Not quite... >> >>],\ S >>4 0 0 0 >>4 3 0 0 >>4 3 2.23607 0 >>4 3 2.23607 0 >> >>I also thought about multiplying it by a diagonal matrix of 0s and 1s >>but couldn't get that figured out either >> >>Thanks >>Joe > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
