ps: just to be clear, the data set behind the above example would be
[
{
"datalogger": "PLV_CEM01",
"data": [
{"date": "15/10/2019", "qty": 117.6},
{"date": "14/11/2019", "qty": 192.8},
{"date": "20/12/2019", "qty": 93.2},
{"date": "02/03/2020", "qty": 69.4}
],
"aggregated_qty": 625.2
},
{
"datalogger": "PLV_PAR01",
"data": [
{"date": "15/10/2019", "qty": 122.4},
{"date": "14/11/2019", "qty": 205.8}
],
"aggregated_qty": 669.6
},
{
"datalogger": "PLV_PAR02",
"data": [
{"date": "15/10/2019", "qty": 120.2},
{"date": "14/11/2019", "qty": 172.2},
{"date": "20/12/2019", "qty": 81.6}
],
"aggregated_qty": 587.6
}
]