Re: Multiplying a vector over multiple vectors

*To*: mathgroup at smc.vnet.net*Subject*: [mg91179] Re: [mg91150] Multiplying a vector over multiple vectors*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Fri, 8 Aug 2008 07:16:23 -0400 (EDT)*Organization*: Mathematics & Statistics, Univ. of Mass./Amherst*References*: <200808070842.EAA02140@smc.vnet.net>*Reply-to*: murray at math.umass.edu

First /@ Outer[Times, {{1, 2}, {3, 4}, {5, 6}}, {{a, b}}, 1] {{a,2 b},{3 a,4 b},{5 a,6 b}} Donald DuBois wrote: > How does one get a vector to distribute over > a list of vectors under multiplication? > > For example: > > {{1,2}, {3,4}, {5,6}} times {a,b} should > equal (under this operation) > > {{a, 2b}, {3a, 4b}, {5a, 6b}} > > If {a,b} is duplicated three times one can > use MapThread as in: > > MapThread[Times, {{{1, 2}, {3, 4}, {5, 6}}, {{a, b}, {a, b}, {a, b}}}] > > but duplicating {a,b} using Table is very slow > when the vectors are large (consisting of thousands > of elemets). > > Thanks in advance for any help you can give me. > > Don > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**Multiplying a vector over multiple vectors***From:*Donald DuBois <donabc@comcast.net>