I have manually recorded power meter readings over the last few years. The data has a period of ~1 day to 1 week (whenever I remembered to write the value down). I have switched to using a wireless meter reader that has much higher and reliable read rate, but I’d like to have the old data available since I have it. I have imported the data into Influxdb such that it has the recorded timestamp and the numeric value. Example:
> select * from excel limit 10 name: excel time reading ---- ------- 1287644400000000000 802 1292313600000000000 1008 1297497600000000000 1279 1300003200000000000 1429 1300258800000000000 1438 1300345200000000000 1441 1300950000000000000 1461 1301468400000000000 1477 1302159600000000000 1501 1306220400000000000 1612
I have read that the derivative function can help with this if the data is all recorded at a fixed interval, but obviously that didn’t happen. Is there a builtin method or recommended approach to calculated either the usage with a non-consistent recording interval? I did this easily within Excel by simply taking the difference in measurement and dividing by the difference in reading date/time.