Re: Rearranging a tensor
- To: mathgroup at smc.vnet.net
- Subject: [mg22455] Re: Rearranging a tensor
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Sat, 4 Mar 2000 02:26:28 -0500 (EST)
- References: <89icvm$n7d@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Mark:
a = {{1, 2}, {3, 4}};
b = Table[1, {3}, {3}];
c = Outer[Times, a, b]
{{{{1, 1, 1}, {1, 1, 1}, {1, 1, 1}}, {{2, 2, 2}, {2, 2, 2}, {2, 2, 2}}},
{{{3,
3, 3}, {3, 3, 3}, {3, 3, 3}}, {{4, 4, 4}, {4, 4, 4}, {4, 4, 4}}}}
Flatten[MapThread[Join, #] & /@ c, 1]
{{1, 1, 1, 2, 2, 2}, {1, 1, 1, 2, 2, 2}, {1, 1, 1, 2, 2, 2}, {3, 3, 3, 4, 4,
4}, {3, 3, 3, 4, 4, 4}, {3, 3, 3, 4, 4, 4}}
Allan
---------------------
Allan Hayes
Mathematica Training and Consulting
Leicester UK
www.haystack.demon.co.uk
hay at haystack.demon.co.uk
Voice: +44 (0)116 271 4198
Fax: +44 (0)870 164 0565
"DIAMOND Mark" <noname at noname.com> wrote in message
news:89icvm$n7d at smc.vnet.net...
> I have
>
> In[1]:= a={{1,2},{3,4}};
>
> In[2]:= b=Table[1,{3},{3}];
>
> In[3]:= c=Outer[Times,a,b]
>
> Out[3]= {{{{1, 1, 1}, {1, 1, 1}, {1, 1, 1}},
>
> > {{2, 2, 2}, {2, 2, 2}, {2, 2, 2}}},
>
> > {{{3, 3, 3}, {3, 3, 3}, {3, 3, 3}}, {{4, 4, 4}, {4, 4, 4}, {4, 4,
4}}}}
>
> In[4]:= c//MatrixForm
>
> Out[4]//MatrixForm=
> 1 1 1 2 2 2
> 1 1 1 2 2 2
> 1 1 1 2 2 2
>
> 3 3 3 4 4 4
> 3 3 3 4 4 4
> 3 3 3 4 4 4
>
> I would now like to rearrange c so that it is of the form
>
{1,1,1,2,2,2},{1,1,1,2,2,2},{1,1,1,2,2,2},{3,3,3,4,4,4},{ 3,3,3,4,4,4},{3,3
> ,3,4,4,4}}
>
> There must be a *simple* way to do this but I cannot see it. Help would be
> appreciated.
>
> Cheers,
>
> Mark R Diamond
> Vision Research Laboratory
> The University of Western Australia
> no spam email: markd at psy dot uwa dot edu dot au
>
>
>