I have covered lots of StackOverflow questions and Google search results, read many discussion topics but I couldn't find any proper answer for my question. I have an Sparse Matrix in .mat format which contains 36600 nodes (36600x36600 adjacency matrix) to read and manipulate (like matrix vector multiplication) in Java Environment. I applied many answers that discussed at here but I always got NullPointerException errors although there was a data at that .mat files.(Some says these result is because of size of data) I have applied these following code to my .mat file that return null and NullPointerException.
MatFileReader matfilereader = new MatFileReader("sourceData.mat");
MLArray mlArrayRetrieved = matfilereader.getMLArray("data");
System.out.println(mlArrayRetrieved);
System.out.println(mlArrayRetrieved.contentToString());
Also I have tried many times to convert .mat file to .csv or .xls in MATLAB Environment and Python Environment at Jupyter Notebook but, I did not get any result at these times, too.
That .mat file is going to be a adjacency matrix and will be a source for a specific algorithm in Cytoscape project. Hence, I must use it at Java Environment and I have decided to use the COLT Library for matrix manipulations. Suggestions and advises are going to help me so much. Thanks for reading.
just use find to get rows, columns and values of nonzeros elements and save these as text,csv or...:
[row, col, v] = find(my_spares_matrix);