How to store a large arrays into cells?

I generate data using a multiplexed data application (6x6 = 36 different conditions, data collected for all at once). I have generated a nice code which takes the entire data file and separates each data point by its condition (1 of 36 possible conditions possible) and would like to arrange the now 36 data files into a single cell array for easy accessing/indexing. I am having trouble (I think) because each individual data file will contain several thousand data points, each with 15 values. In other words, each datafile is a Nx15 matrix.

the conditions in question are 6 antibiotics in 6 different concentrations; this is not super important except to say that the 36 conditions are already arranged in a 6x6 matrix.

for example, say I have antibiotics A, B, C, D, E, F each one in concentrations 1, 2, 3, 4, 5, 6, then the matrix of conditions will be a 6x6:

[ A1 A2...A6

B1 B2...B6

C1 C2...C6

D1 D2...D6

E1 E2...E6

F1 F2...F6 ]

(bearing in mind that each condition, A1 or B6 and so-on will be a Nx15 double, with N different for each of 36 conditions)

If we suppose that i have the example datafiles A1 = 2205 x 15 double, A2 = 2235 x 15 double and A3 = 1807x15 double, I am trying to arrange them into a cell array using a line of code along the lines of:

data{1,1} = A1;

data{1,2} = A2;

data{1,3} = A3;

.......

data{6,6} = F6;

and am receiving the error: "Unable to perform assignment because brace indexing is not supported for variables of this type."

Can someone please help? I am certain that I just have some little syntax wrong but cannot seem to figure it out. As a general reminder, the goal is to generate a single 6x6 cell array, where each cell in the array contains a N x 15 matrix. Thanks in advance,

Carter

[dpb]

A1=rand(12,15);A2=rand(7,15);        % two arrays that match description above
C{1,1}=A1; C{2,1}=A2;                % assign them to a cell array

>> C                                    % show what we gots...
C =
  2×1 cell array
    {12×15 double}
    { 7×15 double}
>> 

The error you're getting is owing to the data variable on LHS of assignment being something else already--

>> clear C; C=zeros(2,1);
>> C{1,1}=A1;
Unable to perform assignment because brace indexing is not supported for variables of this type. 
>> 

So, remove whatever preallocation you did for data or if know the size a priori and want to, you can use

C=cell(2,1);
C{1}=A1;
C{2}=A2;

that sets the size/orientation. You can then use single subscripts and retain the column orientation for C; note still need "the curlies" to put the data into the cell array.

COMMENT

While not the cause of your error, the above coding style with a zillion different named variables with subscripting of each is indicative of not using MATLAB array addressing and syntax very effectively. Would have to have data and/or the way in which the data were generated to see just how to avoid this, but in all likelihood a loop construct with multi-dimensional arrays (3D) to hold the various concentrations or structures or cell arrays earlier in the process would have let you avoid this and probably shortened the code drastically.

[Carter Hoffman]

Do you mean to say that instead of

data{1,1} = A1;
data{1,2} = A2;
data{1,3} = A3;
.......
data{6,6} = F6;

I could have something like

for i = 1:xdim
  for j = 1:ydim
    data { i,j } = _____
  end 
end

?

[dpb]

Yes, but more importantly and it only helps if you don't create explicit variables A1, A2, ..., An but they are then instead an array or struct fields or somesuch so that they can be referenced programmatically instead of by explicit reference.

It wasn't clear to me if the references in the initial post were referring to variables or values...I presumed variables since you said each was an Nx15 array.

[Dyuman Joshi]

Yes, you can do it that way. Something like this

y=rand(120,90);
for i=1:20:120 %you have to define your i according to your data
    for j=1:15:90
        data{ceil(i/20),ceil(j/15)}=y(i:i+19,j:j+14);
    end
end
data

data = 6×6 cell array
    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}
    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}
    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}
    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}
    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}
    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}    {20×15 double}