Re: Deformed Matrix Product

*To*: mathgroup at smc.vnet.net*Subject*: [mg72191] Re: Deformed Matrix Product*From*: dh <dh at metrohm.ch>*Date*: Thu, 14 Dec 2006 05:49:06 -0500 (EST)*References*: <eloom4$mu6$1@smc.vnet.net>

Hi Simone, let's first define a member function that specifies if a term is to be included in the sum or not: memQ[i_,j_,k_]:=If[i<=k ,If[i\[LessEqual]j\[LessEqual]k,1,0] ,If[j\[LessEqual]k||i\[LessEqual]j,1,0] ] With this we do the "inner product" by hand (assuming that the factors have dimension: n x n): DeformedProduct[a_,b_]:=(n=Length[a];Table[Sum[a[[i,j]] memQ[i,j,k] b[[j,k]] ,{j,n}],{i,n},{k,n}])) We can test this by defining two 4x4 matrices: ma = Array[a, {n, n}]; mb = Array[b, {n, n}]; and get the product: DeformedProduct[a,b]//TableForm where we added TableForm for more readability. Daniel simoseve at gmail.com wrote: > Dear All, > > I would like to implement a form of matrix product called deformed > matrix product. > > The definition can be found at page 2 of > > http://ipnweb.in2p3.fr/lptms/membres/pzinn/semi/ium.pdf > > P. Zinn-Justin, Combinatorics of the Brauer Loop scheme. > > Is there any good samaritan out there that knows how to do it? > > Thanks a lot for your time and kind consideration. > > Simone Severini >