I would like to assign a value to the df$lamp_intensity vector depending on a specific time interval within df$date. If a given observation is outside of this interval, I would like to assign an NA. Once I get this first bit of code working, I plan on nesting a bunch of ifelse() statements to handle multiple time intervals. I think I'm pretty close, but I could definitely use a hand.
Thank you!
Here's my data:
df <- structure(list(date = structure(c(1504787028, 1504787030, 1504787031, 1504787032, 1504787033, 1504787034, 1504787035, 1504787036, 1504787037, 1504787038), class = c("POSIXct", "POSIXt"), tzone = "UTC"), ppm = c(0.0009765625, 0.0009765625, 0.0009765625, 0.0009765625, 0.0009765625, 0.0009765625, 0.0009765625, 0.0009765625, 0.0009765625, 0.00146484375)), .Names = c("date", "ppm"), row.names = c(NA, -10L), class = c("tbl_df", "tbl", "data.frame"))
df$lamp_intensity <- ifelse(df$date >= as.POSIXct("2017-09-07 12:23:51",
format = "%Y-%m-%d %H:%M:%S", tz = "UTC") && ## using '&' generates an error message
date <= as.POSIXct("2017-09-07 12:23:55",
format = "%Y-%m-%d %H:%M:%S", tz = "UTC"), 0, NA)
head(df, 10)
The solution would assign 0 for df$lamp_intensity rows between 2017-09-07 12:23:51 and 2017-09-07 12:23:55
You could use the cut function instead. For example:
df$lamp_intensity = cut(df$date,
breaks=as.POSIXct(c("2017-09-07 12:23:42","2017-09-07 12:23:55",
"2017-09-07 12:24:02", "2017-09-07 12:24:31"), tz="UTC"),
labels=c(0,1,2))
date ppm lamp_intensity
1 2017-09-07 12:23:48 0.0009765625 0
2 2017-09-07 12:23:50 0.0009765625 0
3 2017-09-07 12:23:51 0.0009765625 0
4 2017-09-07 12:23:52 0.0009765625 0
5 2017-09-07 12:23:53 0.0009765625 0
6 2017-09-07 12:23:54 0.0009765625 0
7 2017-09-07 12:23:55 0.0009765625 1
8 2017-09-07 12:23:56 0.0009765625 1
9 2017-09-07 12:23:57 0.0009765625 1
10 2017-09-07 12:23:58 0.0014648438 1