Convert vector to matrix

How can I convert a vector of 30482x1 (it is the accumulated of 4 measurements of 17 min at 8 hz) to a matrix that has columns of 8160 data.

[Matt J]

30482 does not divide evenly into 8160,

30482/8160

ans = 3.7355

so your intended rule for reorganizing this data is not clear.

[Fangjun Jiang]

reshape()

[dpb]

On top of which, given the statement that "it is ... 4 measurements of 17 min at 8 hz)"

>> mod(30482,4)
ans =
     2
>>

so the list isn't a complete set of four.

Answer 1

[dpb]

Given the above problems regarding the number of elements in the vector vis a vis the number of channels (and it can't be there's a timestamp as it's also not divisible by five), the best you can do is something like

N=numel(x);                 % x is the data vector, determine how long it actually is
nCh=4;                      % the supposed number of channels/columns
M=N-mod(N,nCh);             % how many nCh records there actually are
x=reshape(x(1:M),[],nCh);   % keep M samples; reshape() to nCh columns

NB --

>> 8160*4
ans =
32640
>> 

[Andres Ulloa]

Thank you so much!