simpler way to get a particular banded matrix?

*To*: mathgroup at smc.vnet.net*Subject*: [mg98079] simpler way to get a particular banded matrix?*From*: rip pelletier <bitbucket at comcast.net>*Date*: Sun, 29 Mar 2009 02:48:12 -0500 (EST)

Hi, The following command constructs a matrix (typically denoted M0, it arises in filter banks in general, in Burrus, Gopinath, & Guo "intro to wavelets and wavelet transforms: a primer" in particular). I'm sure there's a way to do this without typing out all 5 bands. Here's what i did: SparseArray[Band[{1,1}]->H,{6,6}]+ SparseArray[Band[{2,3}]->H,{6,6}]+ SparseArray[Band[{3,5}]->H,{6,6}]+ SparseArray[Band[{-2,-3},{1,1},{-1,-1}]->rH,{6,6}]+ SparseArray[Band[{-3,-5},{1,1},{-1,-1}]->rH,{6,6}] where H={h0,h1,h2,h3,h4,h5}; rH=Reverse[H]; I get what I want: h0 0 0 0 0 0 h2 h1 h0 0 0 0 h4 h3 h2 h1 h0 0 0 h5 h4 h3 h2 h1 0 0 0 h5 h4 h3 0 0 0 0 0 h5 Any easier ways to get this? TIA and vale, rip -- NB eddress is r i p 1 AT c o m c a s t DOT n e t