Full scan of March 2020 - are people self isolating for COVID-19? Seems so.

Extract just March's data, then import it to the database:

grep -E "^2020-03" tcpdump.log > /tmp/march.wifi.log
php trim.php /tmp/march.wifi.log > march-trimmed.csv

Raw data for March was 21Gb, approx 168 million lines.

Then import to the mySQL database:

LOAD DATA INFILE 'march-trimmed.csv' INTO TABLE simple_data;

SELECT DATE(seen_time), COUNT(mac) FROM simple_data WHERE DATE(seen_time) >= '2020-03-01' AND seen_time <= '2020-04-01' GROUP BY DATE(seen_time) INTO OUTFILE '/tmp/march-rawdata.csv';

SELECT DATE(seen_time),COUNT(DISTINCT mac) FROM simple_data WHERE DATE(seen_time) BETWEEN '2020-03-01' AND '2020-03-31' GROUP BY DATE(seen_time) INTO OUTFILE '/tmp/distinct-march.csv';