Refactor and simplify time segments

pull/130/head
JulioV 2021-03-28 14:31:02 -04:00
parent c48c1c8f24
commit 87fbbbe402
4 changed files with 179 additions and 185 deletions

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@ -0,0 +1,42 @@
validate_overlapping_event_segments <- function(segments){
# Check for overlapping segments (not allowed because our resampling episode algorithm would have to have a second instead of minute granularity that increases storage and computation time)
overlapping <- segments %>%
group_by(label) %>%
arrange(segment_start_ts) %>%
mutate(overlaps = if_else(segment_start_ts <= lag(segment_end_ts), TRUE, FALSE),
overlapping_segments = glue("a) [{lag(label)},\t{lag(event_timestamp)},\t{lag(length)},\t{lag(shift)},\t{lag(shift_direction)},\t{lag(device_id)}] \n",
"b) [{label},\t{event_timestamp},\t{length},\t{shift},\t{shift_direction},\t{device_id}]"))
if(any(overlapping$overlaps, na.rm = TRUE))
stop("One or more event time segments overlap for ",overlapping$device_id[[1]],
", modify their lengths so they don't:\n", paste0(overlapping %>% filter(overlaps == TRUE) %>% pull(overlapping_segments), collapse = "\n"))
}
infer_event_segments <- function(tz, segments){
time_format_fn <- stamp("23:51:15", orders="HMS", quiet = TRUE)
inferred <- segments %>%
mutate(shift = ifelse(shift == "0", "0seconds", shift),
segment_start_ts = event_timestamp + (as.integer(seconds(lubridate::duration(shift))) * ifelse(shift_direction >= 0, 1, -1) * 1000),
segment_end_ts = segment_start_ts + (as.integer(seconds(lubridate::duration(length))) * 1000),
segment_id_start = lubridate::as_datetime(segment_start_ts/1000, tz = tz),
segment_id_end = lubridate::as_datetime(segment_end_ts/1000, tz = tz),
segment_end_ts = segment_end_ts + 999,
segment_id = glue("[{label}#{start_date} {start_time},{end_date} {end_time};{segment_start_ts},{segment_end_ts}]",
start_date=lubridate::date(segment_id_start),
start_time=time_format_fn(segment_id_start),
end_date=lubridate::date(segment_id_end),
end_time=time_format_fn(segment_id_end)))
validate_overlapping_event_segments(inferred)
return(inferred)
}
assign_to_event_segments <- function(sensor_data, time_segments){
sensor_data <- sensor_data %>%
group_by(local_timezone) %>%
nest() %>%
mutate(inferred_time_segments = map(local_timezone, infer_event_segments, time_segments),
data = map2(data, inferred_time_segments, assign_rows_to_segments)) %>%
select(-inferred_time_segments) %>%
unnest(data) %>%
arrange(timestamp) %>%
ungroup()
}

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@ -0,0 +1,110 @@
day_type_delay <- function(time_segments, day_type, include_past_periodic_segments){
# Return a delay in days to consider or not the first row of data
delay <- time_segments %>%
mutate(length_duration = duration(length)) %>%
filter(repeats_on == day_type) %>% arrange(-length_duration) %>%
pull(length_duration) %>%
first()
return(if_else(is.na(delay) | include_past_periodic_segments == FALSE, duration("0days"), delay))
}
get_segment_dates <- function(data, local_timezone, day_type, delay){
# Based on the data we are processing we extract unique dates to build segments
dates <- data %>%
distinct(local_date) %>%
mutate(local_date_obj = date(lubridate::ymd(local_date, tz = local_timezone))) %>%
complete(local_date_obj = seq(date(min(local_date_obj) - delay), date(max(local_date_obj) + delay), by="days")) %>%
mutate(local_date = replace_na(as.character(date(local_date_obj))))
if(day_type == "every_day")
dates <- dates %>% mutate(every_day = 0)
else if (day_type == "wday")
dates <- dates %>% mutate(wday = wday(local_date_obj, week_start = 1))
else if (day_type == "mday")
dates <- dates %>% mutate(mday = mday(local_date_obj))
else if (day_type == "qday")
dates <- dates %>% mutate(qday = qday(local_date_obj))
else if (day_type == "yday")
dates <- dates %>% mutate(yday = yday(local_date_obj))
return(dates)
}
infer_existent_periodic_segments <- function(existent_dates, segments){
# build the actual time segments taking into account the data and users' requested length and repeat schedule
# segment datetime labels are computed on UTC
crossing(segments, existent_dates) %>%
pivot_longer(cols = c(every_day,wday, mday, qday, yday), names_to = "day_type", values_to = "day_value") %>%
filter(repeats_on == day_type & repeats_value == day_value) %>%
mutate(segment_id_start = lubridate::parse_date_time(paste(local_date, start_time), orders = c("Ymd HMS", "Ymd HM")) + period(overlap_duration),
segment_id_end = segment_id_start + lubridate::duration(length))
}
dedup_nonoverlapping_periodic_segments <- function(nested_inferred_time_segments){
# Overlapping segments exist when their length is longer than their repeating frequency, e.g. twoday segements starting on every day
# In process_time_segments we decompose those segments into non-overlapping ones, e.g. twodayA +0days and twodayB +1days
# This means that any date will have more than one non-overlapping instances, that we need to dedup
# We choose alternating non-overlapping instances to guarantee any data row is only neeeded in one instance at a time
# d1,r1,twoday0
# d2,r2,twoday0 twoday1
# d3,r3,twoday1 twoday0
# d4,r4,twoday0 twoday1
new_segments <- data.frame(nested_inferred_time_segments %>%
group_by(original_label) %>%
mutate(max_groups = max(overlap_id) + 1) %>%
# select(label, segment_id_start, segment_id_end, overlap_id, max_groups) %>%
nest() %>%
mutate(data = map(data, function(nested_data){
nested_data <- nested_data %>% arrange( segment_id_start, segment_id_end) %>%
group_by(segment_id_start) %>%
mutate(n_id = ((cur_group_id()-1) %% max_groups)) %>%
filter(overlap_id == n_id) %>%
# select(label, segment_id_start, overlap_id, n_id) %>%
ungroup()
})) %>%
unnest(cols = data) %>%
ungroup())
}
add_periodic_segment_timestamps_and_id <- function(segments, local_timezone){
# segment timestamps are computed on the data's timezone(s)
time_format_fn <- stamp("23:51:15", orders="HMS", quiet = TRUE)
segments %>% mutate(segment_start_ts = as.numeric(lubridate::force_tz(segment_id_start, tzone = local_timezone)) * 1000,
segment_end_ts = segment_start_ts + as.numeric(lubridate::duration(length)) * 1000 + 999,
segment_id = glue("[{label}#{start_date} {start_time},{end_date} {end_time};{segment_start_ts},{segment_end_ts}]",
start_date=lubridate::date(segment_id_start),
start_time=time_format_fn(segment_id_start),
end_date=lubridate::date(segment_id_end),
end_time=time_format_fn(segment_id_end) )) %>%
drop_na(segment_start_ts, segment_end_ts)
}
assign_to_periodic_segments <- function(sensor_data, time_segments, include_past_periodic_segments){
time_segments <- time_segments %>% mutate(length_duration = duration(length))
every_day_delay <- duration("0days")
wday_delay <- day_type_delay(time_segments, "wday", include_past_periodic_segments)
mday_delay <- day_type_delay(time_segments, "mday", include_past_periodic_segments)
qday_delay <- day_type_delay(time_segments, "qday", include_past_periodic_segments)
yday_delay <- day_type_delay(time_segments, "yday", include_past_periodic_segments)
sensor_data <- sensor_data %>%
group_by(local_timezone) %>%
nest() %>%
mutate(every_date = map2(data, local_timezone, get_segment_dates, "every_day", every_day_delay),
week_dates = map2(data, local_timezone, get_segment_dates, "wday", wday_delay),
month_dates = map2(data, local_timezone, get_segment_dates, "mday", mday_delay),
quarter_dates = map2(data, local_timezone, get_segment_dates, "qday", qday_delay),
year_dates = map2(data, local_timezone, get_segment_dates, "yday", yday_delay),
existent_dates = pmap(list(every_date, week_dates, month_dates, quarter_dates, year_dates), function(every_date, week_dates, month_dates, quarter_dates, year_dates) reduce(list(every_date, week_dates,month_dates, quarter_dates, year_dates), .f=full_join)),
inferred_time_segments = map(existent_dates, infer_existent_periodic_segments, time_segments),
inferred_time_segments = map(inferred_time_segments, dedup_nonoverlapping_periodic_segments),
inferred_time_segments = map(inferred_time_segments, add_periodic_segment_timestamps_and_id, local_timezone),
data = map2(data, inferred_time_segments, assign_rows_to_segments)) %>%
select(-existent_dates, -inferred_time_segments, -every_date, -week_dates, -month_dates, -quarter_dates, -year_dates) %>%
unnest(cols = data) %>%
arrange(timestamp) %>%
ungroup()
return(sensor_data)
}

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@ -1,81 +1,19 @@
library("tidyverse")
library("glue")
library("lubridate", warn.conflicts = F)
options(scipen=999)
day_type_delay <- function(time_segments, day_type, include_past_periodic_segments){
delay <- time_segments %>% mutate(length_duration = duration(length)) %>% filter(repeats_on == day_type) %>% arrange(-length_duration) %>% pull(length_duration) %>% first()
return(if_else(is.na(delay) | include_past_periodic_segments == FALSE, duration("0days"), delay))
}
get_segment_dates <- function(data, local_timezone, day_type, delay){
dates <- data %>%
distinct(local_date) %>%
mutate(local_date_obj = date(lubridate::ymd(local_date, tz = local_timezone))) %>%
complete(local_date_obj = seq(date(min(local_date_obj) - delay), date(max(local_date_obj) + delay), by="days")) %>%
mutate(local_date = replace_na(as.character(date(local_date_obj))))
if(day_type == "every_day")
dates <- dates %>% mutate(every_day = 0)
else if (day_type == "wday")
dates <- dates %>% mutate(wday = wday(local_date_obj, week_start = 1))
else if (day_type == "mday")
dates <- dates %>% mutate(mday = mday(local_date_obj))
else if (day_type == "qday")
dates <- dates %>% mutate(qday = qday(local_date_obj))
else if (day_type == "yday")
dates <- dates %>% mutate(yday = yday(local_date_obj))
return(dates)
}
create_nonoverlapping_periodic_segments <- function(nested_inferred_time_segments){
new_segments <- (data.frame(nested_inferred_time_segments %>%
group_by(original_label) %>%
mutate(max_groups = max(overlap_id) + 1) %>%
# select(label, segment_id_start, segment_id_end, overlap_id, max_groups) %>%
nest() %>%
mutate(data = map(data, function(nested_data){
nested_data <- nested_data %>% arrange( segment_id_start, segment_id_end) %>%
group_by(segment_id_start) %>%
mutate(n_id = ((cur_group_id()-1) %% max_groups)) %>%
filter(overlap_id == n_id) %>%
# select(label, segment_id_start, overlap_id, n_id) %>%
ungroup()
})) %>%
unnest(cols = data) %>%
ungroup()
))
return(new_segments)
}
assign_rows_to_segments <- function(nested_data, nested_inferred_time_segments){
nested_data <- nested_data %>% mutate(assigned_segments = "")
for(i in seq_len(nrow(nested_inferred_time_segments))) {
segment <- nested_inferred_time_segments[i,]
nested_data$assigned_segments <- ifelse(segment$segment_start_ts<= nested_data$timestamp & segment$segment_end_ts >= nested_data$timestamp,
stringi::stri_c(nested_data$assigned_segments, segment$segment_id, sep = "|"), nested_data$assigned_segments)
assign_rows_to_segments <- function(data, segments){
# This function is used by all segment types, we use data.tables because they are fast
data <- data.table::as.data.table(data)
data[, assigned_segments := ""]
for(i in seq_len(nrow(segments))) {
segment <- segments[i,]
data[segment$segment_start_ts<= timestamp & segment$segment_end_ts >= timestamp,
assigned_segments := stringi::stri_c(assigned_segments, segment$segment_id, sep = "|")]
}
nested_data$assigned_segments <- substring(nested_data$assigned_segments, 2)
return(nested_data)
}
assign_rows_to_segments_frequency <- function(nested_data, nested_timezone, time_segments){
for(i in 1:nrow(time_segments)) {
segment <- time_segments[i,]
nested_data$assigned_segments <- ifelse(segment$segment_start_ts<= nested_data$local_time_obj & segment$segment_end_ts >= nested_data$local_time_obj,
# The segment_id is assambled on the fly because it depends on each row's local_date and timezone
stringi::stri_c("[",
segment[["label"]], "#",
nested_data$local_date, " ",
segment[["segment_id_start_time"]], ",",
nested_data$local_date, " ",
segment[["segment_id_end_time"]], ";",
as.numeric(lubridate::as_datetime(stringi::stri_c(nested_data$local_date, segment$segment_id_start_time), tz = nested_timezone)) * 1000, ",",
as.numeric(lubridate::as_datetime(stringi::stri_c(nested_data$local_date, segment$segment_id_end_time), tz = nested_timezone)) * 1000 + 999,
"]"),
nested_data$assigned_segments)
}
return(nested_data)
data[,assigned_segments:=substring(assigned_segments, 2)]
data
}
assign_to_time_segment <- function(sensor_data, time_segments, time_segments_type, include_past_periodic_segments){
@ -83,116 +21,14 @@ assign_to_time_segment <- function(sensor_data, time_segments, time_segments_typ
if(nrow(sensor_data) == 0 || nrow(time_segments) == 0)
return(sensor_data %>% mutate(assigned_segments = NA))
if(time_segments_type == "FREQUENCY"){
time_segments <- time_segments %>% mutate(start_time = lubridate::hm(start_time),
end_time = start_time + minutes(length) - seconds(1),
segment_id_start_time = paste(str_pad(hour(start_time),2, pad="0"), str_pad(minute(start_time),2, pad="0"), str_pad(second(start_time),2, pad="0"),sep =":"),
segment_id_end_time = paste(str_pad(hour(ymd("1970-01-01") + end_time),2, pad="0"), str_pad(minute(ymd("1970-01-01") + end_time),2, pad="0"), str_pad(second(ymd("1970-01-01") + end_time),2, pad="0"),sep =":"), # add ymd("1970-01-01") to get a real time instead of duration
segment_start_ts = as.numeric(start_time),
segment_end_ts = as.numeric(end_time))
sensor_data <- sensor_data %>% mutate(local_time_obj = as.numeric(lubridate::hms(local_time)),
assigned_segments = "")
sensor_data <- sensor_data %>%
group_by(local_timezone) %>%
nest() %>%
mutate(data = map2(data, local_timezone, assign_rows_to_segments_frequency, time_segments)) %>%
unnest(cols = data) %>%
arrange(timestamp) %>%
select(-local_time_obj) %>%
ungroup()
if (time_segments_type == "FREQUENCY" || time_segments_type == "PERIODIC"){ #FREQUENCY segments are just syntactic sugar for PERIODIC
source("src/data/datetime/assign_to_periodic_segments.R")
sensor_data <- assign_to_periodic_segments(sensor_data, time_segments, include_past_periodic_segments)
return(sensor_data)
} else if (time_segments_type == "PERIODIC"){
# We need to take into account segment start dates that could include the first day of data
time_segments <- time_segments %>% mutate(length_duration = duration(length))
every_day_delay <- duration("0days")
wday_delay <- day_type_delay(time_segments, "wday", include_past_periodic_segments)
mday_delay <- day_type_delay(time_segments, "mday", include_past_periodic_segments)
qday_delay <- day_type_delay(time_segments, "qday", include_past_periodic_segments)
yday_delay <- day_type_delay(time_segments, "yday", include_past_periodic_segments)
sensor_data <- sensor_data %>%
group_by(local_timezone) %>%
nest() %>%
# get existent days that we need to start segments from
mutate(every_date = map2(data, local_timezone, get_segment_dates, "every_day", every_day_delay),
week_dates = map2(data, local_timezone, get_segment_dates, "wday", wday_delay),
month_dates = map2(data, local_timezone, get_segment_dates, "mday", mday_delay),
quarter_dates = map2(data, local_timezone, get_segment_dates, "qday", qday_delay),
year_dates = map2(data, local_timezone, get_segment_dates, "yday", yday_delay),
existent_dates = pmap(list(every_date, week_dates, month_dates, quarter_dates, year_dates),
function(every_date, week_dates, month_dates, quarter_dates, year_dates) reduce(list(every_date, week_dates,month_dates, quarter_dates, year_dates), .f=full_join)),
# build the actual time segments taking into account the users requested length and repeat schedule
inferred_time_segments = map(existent_dates,
~ crossing(time_segments, .x) %>%
pivot_longer(cols = c(every_day,wday, mday, qday, yday), names_to = "day_type", values_to = "day_value") %>%
filter(repeats_on == day_type & repeats_value == day_value) %>%
# The segment ids (segment_id_start and segment_id_end) are computed in UTC to avoid having different labels for instances of a segment that happen in different timezones
mutate(segment_id_start = lubridate::parse_date_time(paste(local_date, start_time), orders = c("Ymd HMS", "Ymd HM")) + period(overlap_duration),
segment_id_end = segment_id_start + lubridate::duration(length),
# The actual segments are computed using timestamps taking into account the timezone
segment_start_ts = as.numeric(lubridate::parse_date_time(paste(local_date, start_time), orders = c("Ymd HMS", "Ymd HM"), tz = local_timezone) + period(overlap_duration)) * 1000,
segment_end_ts = segment_start_ts + as.numeric(lubridate::duration(length)) * 1000 + 999,
segment_id = paste0("[",
paste0(label,"#",
paste0(lubridate::date(segment_id_start), " ",
paste(str_pad(hour(segment_id_start),2, pad="0"), str_pad(minute(segment_id_start),2, pad="0"), str_pad(second(segment_id_start),2, pad="0"),sep =":"), ",",
lubridate::date(segment_id_end), " ",
paste(str_pad(hour(segment_id_end),2, pad="0"), str_pad(minute(segment_id_end),2, pad="0"), str_pad(second(segment_id_end),2, pad="0"),sep =":")),";",
paste0(segment_start_ts, ",", segment_end_ts)),
"]")) %>%
# drop time segments with an invalid start or end time (mostly due to daylight saving changes, e.g. 2020-03-08 02:00:00 EST does not exist, clock jumps from 01:59am to 03:00am)
drop_na(segment_start_ts, segment_end_ts)),
inferred_time_segments = map(inferred_time_segments, create_nonoverlapping_periodic_segments),
data = map2(data, inferred_time_segments, assign_rows_to_segments)
) %>%
select(-existent_dates, -inferred_time_segments, -every_date, -week_dates, -month_dates, -quarter_dates, -year_dates) %>%
unnest(cols = data) %>%
arrange(timestamp)
} else if ( time_segments_type == "EVENT"){
sensor_data <- sensor_data %>%
group_by(local_timezone) %>%
nest() %>%
mutate(inferred_time_segments = map(local_timezone, function(tz){
inferred <- time_segments %>%
mutate(shift = ifelse(shift == "0", "0seconds", shift),
segment_start_ts = event_timestamp + (as.integer(seconds(lubridate::duration(shift))) * ifelse(shift_direction >= 0, 1, -1) * 1000),
segment_end_ts = segment_start_ts + (as.integer(seconds(lubridate::duration(length))) * 1000),
# these start and end datetime objects are for labeling only
segment_id_start = lubridate::as_datetime(segment_start_ts/1000, tz = tz),
segment_id_end = lubridate::as_datetime(segment_end_ts/1000, tz = tz),
segment_end_ts = segment_end_ts + 999,
segment_id = paste0("[",
paste0(label,"#",
paste0(lubridate::date(segment_id_start), " ",
paste(str_pad(hour(segment_id_start),2, pad="0"), str_pad(minute(segment_id_start),2, pad="0"), str_pad(second(segment_id_start),2, pad="0"),sep =":"), ",",
lubridate::date(segment_id_end), " ",
paste(str_pad(hour(segment_id_end),2, pad="0"), str_pad(minute(segment_id_end),2, pad="0"), str_pad(second(segment_id_end),2, pad="0"),sep =":")),";",
paste0(segment_start_ts, ",", segment_end_ts)),
"]"))
# Check that for overlapping segments (not allowed because our resampling episode algorithm would have to have a second instead of minute granularity that increases storage and computation time)
overlapping <- inferred %>% group_by(label) %>% arrange(segment_start_ts) %>%
mutate(overlaps = if_else(segment_start_ts <= lag(segment_end_ts), TRUE, FALSE),
overlapping_segments = paste(paste(lag(label), lag(event_timestamp), lag(length), lag(shift), lag(shift_direction), lag(device_id), sep = ","),"and",
paste(label, event_timestamp, length, shift, shift_direction, device_id, sep = ",")))
if(any(overlapping$overlaps, na.rm = TRUE)){
stop(paste0("\n\nOne or more event time segments overlap for ",overlapping$device_id[[1]],", modify their lengths so they don't:\n", paste0(overlapping %>% filter(overlaps == TRUE) %>% pull(overlapping_segments), collapse = "\n"), "\n\n"))
} else{
return(inferred)
}}),
data = map2(data, inferred_time_segments, assign_rows_to_segments)) %>%
select(-inferred_time_segments) %>%
unnest(data) %>%
arrange(timestamp)
source("src/data/datetime/assign_to_event_segments.R")
sensor_data <- assign_to_event_segments(sensor_data, time_segments)
return(sensor_data)
}
return(sensor_data %>% ungroup())
}

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@ -105,16 +105,22 @@ validate_frequency_segments <- function(segments){
}
prepare_frequency_segments <- function(segments){
#FREQUENCY segments are just syntactic sugar for PERIODIC
validate_frequency_segments(segments)
stamp_fn <- stamp("23:10", orders = c("HM"), quiet = TRUE)
stamp_fn <- stamp("23:10:00", orders = c("HMS"), quiet = TRUE)
new_segments <- data.frame(start_time = seq.POSIXt(from = ymd_hms("2020-01-01 00:00:00"),
to=ymd_hms("2020-01-02 00:00:00"),
by=paste(segments$length, "min")))
new_segments <- new_segments %>%
head(-1) %>%
mutate(start_time = stamp_fn(start_time),
length = segments$length,
label = paste0(segments$label, str_pad(row_number()-1, width = 4, pad = "0")))
mutate(label = paste0(segments$label, str_pad(row_number()-1, width = 4, pad = "0")),
start_time = stamp_fn(start_time),
length = paste0((segments$length * 60)-1, "S"),
repeats_on = "every_day",
repeats_value=0,
overlap_id = 0,
original_label = label,
overlap_duration = "0D")
}