[R] aggregation of irregular interval time-series

Enrico Gabrielli enr|cog@br|e|||76@per@gr @end|ng |rom gm@||@com
Wed Jun 9 19:57:30 CEST 2021

I just registered on the list.
I am an agricultural technician and I am collaborating on a research
project on agroforestry and Brown Marmorated Stink Bug (Halyomorpha
halys, abbreviated BMSB).

Through kobotoolbox we are collecting data of catches in traps on
farms. Farms register inconsistently.
I am trying to use packages for irregular time series.

Here an exemple
the data:
# variable monitoring time as register an import from kobotoolbox
tempo <- as.POSIXct(c("2021-05-29 17:00:00 UTC","2021-06-05 10:52:00
UTC","2021-06-01 17:00:00 UTC","2021-05-16 08:34:00 UTC","2021-06-05
17:00:00 UTC","2021-05-29 05:30:00 UTC","2021-05-23 06:30:00
UTC","2021-05-20 13:00:00 UTC","2021-05-15 12:09:00 UTC"))
# variable capture of BMSB
catture <- c(25,92,23,2,5,30,23,3,15)
# resulting table
arvaia_catture <- data.table(tempo,catture)
# order by time
arvaia_catture_order <- arvaia_catture[order(arvaia_catture$tempo)]

the catches refer to an interval, which goes from the previous
monitoring up to the one recorded on the date
our aim is to calculate the weekly catch
also when a farmer, for example, enters the data on Thursday and
of the following week, on Tuesday in the trap he will find individuals
who were also captured on Friday and Saturday, which formally are to be
considered in the previous week.

With the data of the example
the results (with a spreadsheet) is
two possibile solution
week            simple SUM week         right SUM week
19      17      19,44027778
20      26      52,91388889
21      55      46,4375
22      120     99,20833333
The right SUM week is right!

I have made several attempts
with lubridate, padr, xts
but the last one seems interesting to me
with DTSg
x_periodic <- alter(x,na.status = 'explicit',from="2021-05-15
colapply(x_periodic, fun = interpolateLinear)
I managed to create a vector with all interpolated hours
but with DTSg I still can't aggregate by week

Has anyone on the list ever faced such a problem?

Thank you

Perito agrario Enrico Gabrielli
Tessera n. 633 Collegio Periti agrari prov. Di Modena
Biblioteca agricoltura: https://www.zotero.org/groups/aplomb/
skype: enricogabrielli (enricogabrielli76.peragr using gmail.com)

More information about the R-help mailing list