Hi Bo, The particular monadic case 2&simplify, as I understand it, produces a vector (of size two) which has the same two moments as the original vector (e.g., if the argument Y is a vector of univariate observations, for instance the heights of a group of N people then the product of 2&simplify Y would be a vector Z of two "heights" which would have the same mean and variance as Y ).
Now, assume one also has the weights of the same group of people and the bivariate observations Y contains now their heights and weights collected as a matrix with N rows and two columns (height and weight). The problem is: find another matrix Z of "heights and weights" with a minimum number M of rows (M <: N) such that the (1x2) mean vector and the (2x2) variance-covariance matrix of Z are the same as the mean and variance-covariance matrix of Y . More generally, what would be the corresponding Z for multivariate observations? (I guess the number of rows M , apart from rounding, should depend linearly on the number of columns of the multivariate observations.) I was just wondering if you had consider that kind of problems. On Fri, Jun 26, 2015 at 3:50 AM, 'Bo Jacoby' via Programming < [email protected]> wrote: > Explanation: The vector 'A simplify B' has the same A moments as the > vector B.Examples: 1 simplify 0 21 2 simplify 0 20 2 3 simplify 0 > 2_0.224745 1 2.22474 2 simplify 3 simplify 0 20 2 1 simplify 3 simplify > 0 21 > > > > > Den 0:04 fredag den 26. juni 2015 skrev Kip Murray < > [email protected]>: > > > > 1 X > > 2 X X > > 3 > > 4 X > > 5 > > 6 X > > > 1 X > > 2 > > 3 X > > 4 > > 5 X > > 6 > > > 1 > X > 2 X > > 3 > > 4 > > 5 X > > 6 > > > Above I have attempted three histograms. The first shows the data set 1 2 > 2 4 6 which has mean 3 and standard deviation 2, median 2 and fourths (not > quartiles) 1.5 and 5 . The second histogram shows the mean and the mean > plus or minus a standard deviation, and the third histogram shows the > median and fourths. (The fourths are respectively the median of the > numbers below the median, and the median of the numbers above the median.) > > --Kip Murray > > > On Thursday, June 25, 2015, Devon McCormick <[email protected]> wrote: > > > I put together this J based on the "fivenum" routine in R mentioned in > the > > Wikipedia link: > > > > fivenum=: 3 : 0 > > if. 0=#y=. /:~y do. 5#_. > > else. n4=. -:<.-:3+#y > > d=. <:1,n4,(-:>:#y),(n4-~>:#y),#y > > -:(y{~<.d)+y{~>.d > > end. > > ) > > > > It returns the minimum, the quartile points, and the maximum of a series. > > The first branch of the "if" roughly replicates some of the R function's > > NA-handling. > > > > On Thu, Jun 25, 2015 at 10:14 AM, David Lambert <[email protected] > > <javascript:;>> > > wrote: > > > > > Is simplify supposed to report the i.x moments of the data? Would be > > > useful. > > > When I removed the question marks from simplify to make valid j > > > 1 simplify DATA NB. does report the mean > > > Otherwise I haven't made sense of the results for the verb I created. > > > > > > datatype N > > > integer > > > > > > 3 simplify N > > > _951.236j1533.8 _951.236j_1533.8 2658.39 > > > > > > Date: Thu, 25 Jun 2015 08:39:51 +0000 (UTC) > > >> From: "'Bo Jacoby' via Programming"<[email protected] > > <javascript:;>> > > >> To: Programming Forum<[email protected] <javascript:;>> > > >> Subject: [Jprogramming] simplify > > >> Message-ID: > > >> < > [email protected] > > <javascript:;>> > > >> Content-Type: text/plain; charset=UTF-8 > > >> > > >> NB.?If you have got a bunch of numbers? ? ? ]n=.?20#10035 32 66 37 94 > 56 > > >> 44 30 25 70 27 68 49 92 96 79 74 99 72 22NB. and you want to simplify, > > then > > >> take the mean value > > >> > > > > > > <unreadable cut> > > >> > > > > > > )NB.?If you can simplify the programming, the please let me know. > > >> ThanksBo > > >> > > > > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > > > > > > -- > > Devon McCormick, CFA > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > -- > Sent from Gmail Mobile > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
