Working in R, I need to calculate daily infusion volume (mL) given a variable infusion rate (mL/hour).
My dataframe has two columns: date (year, month, day, hours, mins, sec) when the infusion rate was changed, and the new infusion rate (ml/hr). From these data I have calculated cumulative infusion volume for the entire study (~ 3 weeks duration). I now need to calculate infusion volume for every 24 hours, midnight to midnight. The first and last study days are less than 24 hours duration and are excluded.
I don't know how to approach my problem with infusion rates spanning across 24 hour time periods at midnight.
One thought was to generate a new data frame consisting of time in secs (from zero to end of study) and volume infused per second, then sum infusion volume every day. This of course will generate a large (unnecessary) dataframe (>1 million rows).
I am looking for direction on how to approach in R.
No code to share at this time. My dataframe is shared:https://drive.google.com/file/d/1YfZkuOStOxWIXrxklWEo1r46hjFQPIXM/view
DF <- structure(list(`date&time` = structure(c(1519043251, 1519047111,
1519049877, 1519050201, 1519053454, 1519054180, 1519060742, 1519062334,
1519083584, 1519108892, 1519114732, 1519118888, 1519127198, 1519140960,
1519142031, 1519150508, 1519161027, 1519167167, 1519206508, 1519206877,
1519222879, 1519278875, 1519290863, 1519293411, 1519314864, 1519317665,
1519334695, 1519364934, 1519364996, 1519378625, 1519384577, 1519428049,
1519495090, 1519541667, 1519544091, 1519551993, 1519594678, 1519626216,
1519650059, 1519658045, 1519712871, 1519722853, 1519726863, 1519744270,
1519786071, 1519787755, 1519788820, 1519789685, 1519791798, 1519801303,
1519801380, 1519809813, 1519815924, 1519826260, 1519830433, 1519833629,
1519841284, 1519857415, 1519885051, 1519885120, 1519885141, 1519887091,
1519939049, 1519939482, 1519945740, 1519971397, 1519975527, 1519987363,
1519988481, 1520004464, 1520033974, 1520093329, 1520179994, 1520204550,
1520233073, 1520237983, 1520238103, 1520241519, 1520241904, 1520263216,
1520290670, 1520349278, 1520370509, 1520406514, 1520436434, 1520447318,
1520456518, 1520461383, 1520501027, 1520522600, 1520542062, 1520590191,
1520618693, 1520621059, 1520626341, 1520627226, 1520630596, 1520637370,
1520664044, 1520676143, 1520689466, 1520717079, 1520724147, 1520754787,
1520788241, 1520806426, 1520818840, 1520829807, 1520839843, 1520839936,
1520891100, 1520897458, 1520921676, 1520933752), class = c("POSIXct",
"POSIXt"), tzone = "UTC"), `infusion rate` = c(25.75, 30.75,
25.75, 25.81, 25.81, 25.75, 25.65, 25.65, 27.55, 18.47, 18.25,
16.25, 15.25, 13.25, 13.25, 15.25, 16.25, 15.25, 15.45, 12.45,
12.25, 12.45, 11.45, 11.5, 11.57, 13.57, 11.57, 10.57, 10.55,
11.55, 13.55, 13.52, 13.56, 13.64, 13.7, 13.67, 13.67, 13.65,
14.65, 14.61, 14.67, 14.69, 13.69, 13.67, 16.67, 21.67, 24.67,
29.67, 34.67, 29.67, 29.65, 24.65, 22.65, 19.65, 19.65, 17.65,
14.65, 14.63, 14.65, 15.65, 14.65, 15.65, 16.65, 15.65, 15.68,
15.71, 15.74, 15.81, 15.92, 15.89, 15.9, 15.94, 15.93, 14.94,
15.92, 16.03, 15.03, 15, 15.02, 14.96, 14.91, 14.93, 14.94, 14.94,
14.91, 14.92, 14.92, 14.92, 14.94, 14.95, 15.95, 14.95, 16.95,
19.95, 22.95, 25.95, 26.95, 26.93, 26.89, 23.89, 20.89, 18.89,
18.87, 16.87, 15.87, 15.87, 14.87, 17.87, 16.87, 16.98, 17.98,
16.98, 15.98, 0)), row.names = 2:115, class = "data.frame")
I need the output to be two columns of data; time in days and daily infusion volume.
