After getting bokeh to graph data I started trying to compare years/months which did not quite go to plan especially as i had forgotten that despite dragelec running for almost 5yrs the SQL recording only started in Aug 2018…
There is another issue; the way the data is recorded; i store values everytime a signal is output from one of the sensors it means when interrogating the data i can have a different number of values per day so a straight forward export of data does not work.
For example the following SQL select statement
for row in curs.execute("SELECT * FROM home_mon WHERE DATE>(?) and DATE<(?)", ('2018-12-01', '2018-12-25')):
counts 6547 rows for December 2018 whilst the same for 2019 only counts 6516 this discrepancy is larger for some other months. So to compare periods i wrote the following to get one value per hour
for row in curs.execute("SELECT * FROM home_mon WHERE DATE>(?)", (yr18,)): dat = dt.datetime.fromtimestamp(int(float(row))).strftime('%Y-%m-%d %H:%M:%S') hr = dt.datetime.fromtimestamp(int(float(row))).strftime('%H:') if dat > "2018-12-01" and dat < "2018-12-25": if hr != pasthr18: pasthr18 = hr data_18.append(row) if dat > "2019-12-01" and dat < "2019-12-25": if hr != pasthr19: pasthr19 = hr data_19.append(row) cnt = cnt + 1 x.append(cnt)
The result of this is for the periods 01-12 > 25-12 in both years I get 576 values for both meaning a real comparison can now be done.
So using bokeh to graph the period we get;
and the same in excel but tweaked to show date axis;
a bit of further exploration gives;
|Coldest recorded value||Time||Value|
|14th December 2018||04:01:47||-3.2|
|17th December 2019||23:01:51||-1.18|
|Warmest recorded value||Time||Value|
|02nd December 2018||12:05:41||12.59|
|19th December 2019||13:02:53||10.56|
Finally the average temperatures for the period 01st-25th December 2018 vs 2019
This year would appear to provide a warm start for the next with an almost 12degC rise from the 17th to 19th of December and as i'm writing this [2019-12-30 Mon 14:57] the grass is green, the sun is shining, it's 7.4degC outside but if i ignore the lack of leaves on the trees it looks like a late summers evening.