Hi,
tall arrays are more typically used when you have a single file or a set of files that is too large to be imported into memory at once.
One way I see to solve the challenge you are facing is to create only parts (e.g., leaving one of the variables constant for the time would "only" require 60^6 * 8 * 2 bytes = about 12 GB rather than 60^6 * 8 * 2 bytes = about 746 GB - sizes corrected compared to original post) of the data at a time and do the preprocessing you will need for the scatter plot. For example, you could use histcounts2 to bin the data, accumulate this over the parts, and then use heatmap for visualization.
That's just the idea - please let me know if you want to pursue this and need additional help with the implementation.
Another question will be computational efficiency. For this example, you can explicitly calculate the trace of the inverse, and it is a not overly complicated formula:
syms a b c d e f
M = [a d e; d b f; e f c];
simplify(trace(inv(M)))
That way, you can calculate the trace of a huge number of matrices and their inverses in a vectorized way.
This may also give you additional insights, such as: trace of inverse will be large, when denominator of that expression is close to 0.
Best wishes,
Harald
