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By virtue of the suggestion in my previous question, I constructed the sparse matrix whose size is $518400 \times 86400$, mostly filled with $0$ and $\pm 1$. Now I want to calculate its rank.

Since RowReduce requires a huge amount of memory to fill in $0$s, my first approach was to divide the matrix into many parts, e.g., each containing 144 rows ($144\times 86400$).

Module[{i, part, rank},
 For [i = 0, 144 (i + 1) <= 518400, i++,
   part = RowReduce[input[[144*i + 1 ;; 144 (i + 1)]]];
   rank = MatrixRank[part];
   If[i == 0, result = part[[1 ;; rank]], 
    result = Join[result, part[[1 ;; rank]]]]

Unfortunately, this does not work because all rows in each part are linearly independent so that the number of rows does not decrease.

Does anyone have such an experience? Should I export the matrix to the file and calculate its rank via other language / packages? If so, any suggestion?

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