I am not aware of any harm done (unlike Brutus). On the contrary, I provided in an elegant and, apparently, efficient solution.
And that on Friday 13th. R.E. Boss -----Original Message----- From: Programming <[email protected]> On Behalf Of Henry Rich Sent: vrijdag 13 november 2020 21:38 To: [email protected] Subject: Re: [Jprogramming] Getting indices of matrix elements /Et tu, R. E.?/ Using $. for this is using a sledgehammer to crack an egg. Henry Rich On 11/13/2020 3:00 PM, R.E. Boss wrote: > $.$.M > 0 0 │ 1 > 0 1 │ 2 > 0 2 │ 3 > 0 3 │ 4 > 1 0 │ 5 > 1 1 │ 6 > 1 2 │ 7 > 1 3 │ 8 > 2 0 │ 9 > 2 1 │ 10 > 2 2 │ 11 > 2 3 │ 12 > > > R.E. Boss > > > -----Original Message----- > From: Programming <[email protected]> On Behalf Of > thomas.bulka via Programming > Sent: vrijdag 13 november 2020 18:05 > To: [email protected] > Subject: [Jprogramming] Getting indices of matrix elements > > Hi everyone, > > still learning J, I stumbled across a problem which should be easy to solve, > but somehow I have not been able to do so, yet. Say, I have defined a matrix > M: > > M =: 3 4 $ >: i. 12 > > I now want to get the row and column index of 6 in M, which is 1 2. If M was > a vector, I could easily get the index of 6 with the help of I.: > > I. 6 = , M > > Applying I. to M in its original shape, however, returns a boolean vector > which indicates in which rows 6 has been found (at least that is my > interpretation). > > Is it possible to apply I. to higher rank arrays in order to receive the > complete indices of the elements I'm looking for? Or should I approach that > problem in another way? > > Thank you very much in advance for your help! > > Kind regards, > > Thomas > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm -- This email has been checked for viruses by AVG. https://www.avg.com ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
