Re: Integrating a Matrix

*To*: mathgroup at smc.vnet.net*Subject*: [mg132067] Re: Integrating a Matrix*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Fri, 29 Nov 2013 03:49:34 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <20131127062412.B370C69F5@smc.vnet.net> <20131128072213.497336A3D@smc.vnet.net>

I forgot what the ref/NIntegrate explicitly shows, in the Examples > Basic Examples section: that NIntegrate will apply directly to the individual entries of a vector or matrix =97 or, presumably, higher-order array. So now flattening at start, restructuring at end, is required. It would be nice to have this automatic threading documented in some way other than in two examples. But that sort of thing is a shortcoming of a lot of the documentation. On Nov 28, 2013, at 2:22 AM, Murray Eisenberg <murray at math.umass.edu> wrote: > Perhaps something like the following (very simple example)? > > mat = Table[f[i, j][x], {i, 1, 3}, {j, 1, 3}] > Partition[(NIntegrate[#, {x, 0, 1}] &) /@ Flatten[mat], 3] > > > On Nov 27, 2013, at 1:24 AM, David Barnes <barnes at pullman.com> wrote: > >> I have a 3X3 matrix of functions fij[x], for i,j = 1,2,3, and I want to NIntegrate all nine elements over 0<x<1 to get a matrix of constants. Is there an easy way to do this other that doing 9 individual NIntegration's? >> > > --- > Murray Eisenberg > murray at math.umass.edu > Mathematics & Statistics Dept. > Lederle Graduate Research Tower > University of Massachusetts > 710 North Pleasant Street > Amherst, MA 01003-9305 > > > > > >

**References**:**Integrating a Matrix***From:*David Barnes <barnes@pullman.com>

**Re: Integrating a Matrix***From:*Murray Eisenberg <murray@math.umass.edu>