How do I convert a 3x153 double to a 1x51 matrix?

How do I convert a 3x153 double to a 1x51 cell in matricies?

And how do i multiply the answer by another matrix?

Answer 1

[Voss]

% Create a 3-by-153 matrix with random data:
A = rand(3,153)

A = 3×153

0.5433 0.6291 0.4386 0.5241 0.0914 0.0000 0.9038 0.2952 0.5301 0.3555 0.4609 0.3361 0.4971 0.0970 0.1655 0.9147 0.8005 0.1063 0.7997 0.3971 0.4286 0.2630 0.8137 0.5320 0.2307 0.0771 0.5516 0.6792 0.8076 0.5351 0.5830 0.9466 0.2688 0.4836 0.4363 0.3615 0.9788 0.5664 0.0413 0.7764 0.2215 0.3344 0.8738 0.6815 0.1681 0.3619 0.4323 0.7664 0.4851 0.3024 0.1976 0.8913 0.9349 0.4100 0.2430 0.1706 0.2821 0.5143 0.8689 0.8467 0.3622 0.1169 0.8223 0.3986 0.8539 0.1651 0.5621 0.4888 0.7972 0.8604 0.2780 0.2099 0.4152 0.2517 0.9207 0.2562 0.4731 0.5349 0.9553 0.3081 0.7120 0.0011 0.7367 0.5669 0.7112 0.0011 0.9548 0.6397 0.4202 0.7933

% Convert the 3-by-153 matrix to a 1-by-51 cell array, with each element being a 3-by-3 matrix:
C = mat2cell(A,3,3*ones(1,51))

C = 1×51 cell array
    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}

% Verify the size of the cell array:
size(C)

ans = 1×2

1 51

% Verify that the first element of C is the first 3 columns of A:
C{1}

ans = 3×3

0.5433 0.6291 0.4386 0.5830 0.9466 0.2688 0.3622 0.1169 0.8223

isequal(C{1},A(:,1:3))

ans = logical
   1

% Now multiply each element of C by some other matrix B of unspecified size (using 3-by-3 here):
B = magic(3)

B = 3×3

8 1 6 3 5 7 4 9 2

% matrix mulitplication:
D = cellfun(@(x)x*B,C,'UniformOutput',false)

D = 1×51 cell array
    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}

D{1}

ans = 3×3

7.9884 7.6367 8.5409 8.5790 7.7350 10.6618 6.5375 8.3474 4.6360

% or element-wise multiplication:
D = cellfun(@(x)x.*B,C,'UniformOutput',false)

D = 1×51 cell array
    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}    {3×3 double}

D{1}

ans = 3×3

4.3465 0.6291 2.6319 1.7490 4.7330 1.8814 1.4488 1.0519 1.6446