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Re: How to deal with big matrix 2

  • To: mathgroup at smc.vnet.net
  • Subject: [mg116737] Re: How to deal with big matrix 2
  • From: Bob Hanlon <hanlonr at cox.net>
  • Date: Fri, 25 Feb 2011 06:37:26 -0500 (EST)

m = 3; n = 2;

mat1 = Array[x, {m, n}];

mat2 = Array[y, {m, n}];

Timing[mat3 = Transpose[{Flatten[mat1], Flatten[mat2]}]]

{0.131434, {{x[1, 1], y[1, 1]}, {x[1, 2], y[1, 2]}, {x[2, 1], 
   y[2, 1]}, {x[2, 2], y[2, 2]}, {x[3, 1], y[3, 1]}, {x[3, 2], 
   y[3, 2]}}}

m = 1100; n = 1300;

mat1 = Array[x, {m, n}];

mat2 = Array[y, {m, n}];

Timing[mat3 = Transpose[{Flatten[mat1], Flatten[mat2]}];]

{1.21796, Null}


Bob Hanlon

---- Szymon Roziewski <szymon.roziewski at gmail.com> wrote: 

=============
Any suggestions?

2011/2/23 Szymon Roziewski <szymon.roziewski at gmail.com>

> Hello there,
>
> I have such a case, I have two matrices and each of them is sized 1100x1300
> e.g.
> I would like to create a vector with length 1 430 000 and each of element
> of
> this vector should be {matrxi1_el1x1, matrix2_el1x1}, {matrxi1_el1x2,
> matrix2_el1x2},... , {matrxi1_el1100x1300, matrix2_el1100x1300}
> How to do it without using Do[Do[...]] because it consumes a lot of my
> time.
>
>
> kind regards,
> Szymon Roziewski
>


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