I am trying to index from Cell array

I have a nested cell array

pos{1X4} 
>> {6830X1}{6824X1}{6834X1}{6826X1}{6842X1}{6840X1}{6836X1}{6844X1}{6837X1}{6833X1}

I am trying to index from cell array, but I am getting Unable to use a value of type cell as an index.

position_0{tr} = pos(time_0);

[dpb]

Post a SMALL example that illustrates the storage and what you're trying to get -- it's certainly not clear how a 1x4 is related to what you show that has like 10 humongous vectors strung together...

Once it is known what the actual storage is, the addressing code will work whether there are 5 or 1E6 elements in the arrays, so make it easy on yourself and debug the small problem first.

First off, of course, is to reconsider how you got such a convoluted problem to solve in the first place--illustrating how this comes about may lead to a far more efficient and convenient storage scheme.

[Imraan Ibrahim]

It sounds like time_0 is a cell.

time_0 should to be positive integers or logical values

[Kiran Isapure]

lmin=cellfun(@min, pos, 'UniformOutput', false); %create variable with minimum ROI position

lmax=cellfun(@max, pos, 'UniformOutput', false); %create variable with maximum ROI position

time_0 = cellfun(@(t) find(t == 0,1), t, 'UniformOutput',false); %find index where time = 0 (ROI starts)

%position when ROI starts

position_0{tr} = pos(time_0);

b1 = pos - position_0; %shift TBa position to start at 0 when ROI starts

So this is part of code where I am facing porblem and time_0 is cell array

[Imraan Ibrahim]

Have you tried the answer I gave?

More info is probably needed but, from the code that I'm seeing you don't need the 'UniformOutput'

time_0 = cellfun(@(t) find(t == 0,1), t, 'UniformOutput',false);

can be changed to:

time_0 = cellfun(@(t) find(t == 0,1), t);

and that should make time_0 a numerical array instead of a cell array, then you will be able to use time_0 to index the pos variable

[Kiran Isapure]

Yes I tried, but both is code are not working.

Now I am getting this erorr

Index exceeds the number of array elements. Index must not exceed 11.

[Imraan Ibrahim]

ok that sounds my suggestion has fixed one problem and uncovered another.

Without having the raw data infront of me, I'm making assumtions.

I think this new error is because pos is an array of 11 elements and one or more values in the time_0 array is greater than 11. And so the you get the Index exceeds the number of array elements. Index must not exceed 11. error

[Kiran Isapure]

Both the array are 11, I am still figuring why I am getting this errorr-Index exceeds the number of array elements. Index must not exceed 11.

I am attcahing the Raw here now.

[Imraan Ibrahim]

I've just downloaded the raw data

The 1st cell of both time_0.mat and pos.mat is empty so that would cause a problem.

pos =

1×11 cell array

{0×0 double} {6830×1 double} {6824×1 double} {6834×1 double} {6826×1 double} {6842×1 double} {6840×1 double} {6836×1 double} {6844×1 double} {6837×1 double} {6833×1 double}

time_0 =

1×11 cell array

{0×0 double} {[1002]} {[1002]} {[1002]} {[1002]} {[1002]} {[1002]} {[1002]} {[1002]} {[1002]} {[1002]}

Try the following:

position_0 = cellfun(@(p,t)  p(t), pos, time_0, 'UniformOutput', false);

Bear in mind that the 1st index of position_0 will also be empty

position_0 =

1×11 cell array

{0×0 double} {[86.9711]} {[86.9943]} {[87.0181]} {[87.0761]} {[87.0062]} {[87.0405]} {[86.9515]} {[86.9467]} {[87.0836]} {[86.9525]}

Answer 1

[Imraan Ibrahim]

It sounds like time_0 is a cell.

time_0 should to be positive integers or logical values

I'm assuming that time_0 is a cell containing an array of indices.

If that is the case, you can try something like:

position_0{tr} = pos([time_0{:}]);