Burak_Özbagci asked . 2021-07-12

How can I change a cell array with timepoints in to a continous

How can I change a cell array with timepoints in to a continous binary matrix? (for Neural Network Toolbox)

I have a 15x1 cell array, in which each cell is another 50x2 cell. The data shows spike-event onsets in seconds for 50 neurons (each row is a neuron). The content looks like this:
 
 
 

 

    (XX{1,1}) = 
    {[  3.4078]}    {[  3.7273]}
    {0×0 double}    {0×0 double}
    {0×0 double}    {0×0 double}
    {[  3.4684]}    {0×0 double}
      ...
If this data is used for network training, this is the error that I get:
 
 
Error using trainNetwork (line 140)
Invalid training data. Predictors must be a cell array of sequences. The data dimension of all sequences must be the same.
Caused by:
  Error using nnet.internal.cnn.util.TrainNetworkDataValidator/assertValidSequenceInput (line 269)
  Invalid training data. Predictors must be a cell array of sequences. The data dimension of all sequences must be the same.

In order to use this as an input for a LSTM-Network in the Neural Network Toolbox these timepoints needs to be part of a continous spectrum. My idea was to convert this discrete datapoints in to large binary matrix (50x10000) inwhich the columns represent the time, therefore 10 seconds = 10000 columns. At each timepoint a spike occured (e.g. 3.4078) a 1 should be put for the corresponding neuron. I tried indexing the cell array with a time-vector ( t = (0:0.001:10) ) but it didn't work. Can anyone help transforming the data? Thank you.

neural network , cell arrays , indexing

Expert Answer

John Williams answered . 2024-04-21 08:15:18

If I am understanding you correctly, you would like to change each 50x2 cell array into a 50x10000 matrix of mainly zeros, with a value of 1 at indices that correspond to the times in the original 50x2 array. You can do this by making a new 15x1 cell array in which each cell is a 50x10000 matrix of zeros. Then, use the times in the original array to index into the matrices of zeros to set the corresponding entry to 1. This would look something like:
 
 
% XX = original cell array
seqNum = 15;
neuronNum = 50;

% create new cell array
XX2 = cell([seqNum 1]);
for i = 1:seqNum
    XX2{i} = zeros(neuronNum, 10000);
    currSeq = XX{i};
    for j = 1:neuronNum
        % convert times into indices
        a = round(currSeq{j,1}*10000);
        b = round(currSeq{j,2}*10000);
        % Index into array of zeros
        XX2{i}(j, [a b]) = 1;
    end
end


Not satisfied with the answer ?? ASK NOW

Frequently Asked Questions

MATLAB offers tools for real-time AI applications, including Simulink for modeling and simulation. It can be used for developing algorithms and control systems for autonomous vehicles, robots, and other real-time AI systems.

MATLAB Online™ provides access to MATLAB® from your web browser. With MATLAB Online, your files are stored on MATLAB Drive™ and are available wherever you go. MATLAB Drive Connector synchronizes your files between your computers and MATLAB Online, providing offline access and eliminating the need to manually upload or download files. You can also run your files from the convenience of your smartphone or tablet by connecting to MathWorks® Cloud through the MATLAB Mobile™ app.

Yes, MATLAB provides tools and frameworks for deep learning, including the Deep Learning Toolbox. You can use MATLAB for tasks like building and training neural networks, image classification, and natural language processing.

MATLAB and Python are both popular choices for AI development. MATLAB is known for its ease of use in mathematical computations and its extensive toolbox for AI and machine learning. Python, on the other hand, has a vast ecosystem of libraries like TensorFlow and PyTorch. The choice depends on your preferences and project requirements.

You can find support, discussion forums, and a community of MATLAB users on the MATLAB website, Matlansolutions forums, and other AI-related online communities. Remember that MATLAB's capabilities in AI and machine learning continue to evolve, so staying updated with the latest features and resources is essential for effective AI development using MATLAB.

Without any hesitation the answer to this question is NO. The service we offer is 100% legal, legitimate and won't make you a cheater. Read and discover exactly what an essay writing service is and how when used correctly, is a valuable teaching aid and no more akin to cheating than a tutor's 'model essay' or the many published essay guides available from your local book shop. You should use the work as a reference and should not hand over the exact copy of it.

Matlabsolutions.com provides guaranteed satisfaction with a commitment to complete the work within time. Combined with our meticulous work ethics and extensive domain experience, We are the ideal partner for all your homework/assignment needs. We pledge to provide 24*7 support to dissolve all your academic doubts. We are composed of 300+ esteemed Matlab and other experts who have been empanelled after extensive research and quality check.

Matlabsolutions.com provides undivided attention to each Matlab assignment order with a methodical approach to solution. Our network span is not restricted to US, UK and Australia rather extends to countries like Singapore, Canada and UAE. Our Matlab assignment help services include Image Processing Assignments, Electrical Engineering Assignments, Matlab homework help, Matlab Research Paper help, Matlab Simulink help. Get your work done at the best price in industry.