redundancy in transfer output files in sampling mode

[flass]

Hi Benoit,

I first wanted to confirm that v1.2.0 works well, with scenarios that make sense and no bugs. Well done!

Only one thing I found was not correct was the output in reconciliations/*_transfers.txt files are redundant: For every file reconciliations/*_$n_transfers.txt with $n an integer corresponding to a sampled scenario, the content is a concatenate of the record of the transfer events in that scenario, appended to the content of the transfer file for the previous scenario in the sample $(( $n - 1 )). This concatenation accumulates over each iteration, so the transfer file for scenario n=99 is roughly a hundred times bigger than the file for scenario n=0.

Once removed the redundancy, the records of events are distinct, showing that the sampling is taking place correctly.