Using apply() for nested for loop in R [duplicate] - r

This question already has answers here:
Complex non-equi merge in R
(3 answers)
Closed 2 years ago.
I wrote a nested for loop in R, but the loop is taking way too long to run. I have two big datasets. For every row in dfA and for every row in dfB, the loop should see if Date in dfA falls within Date Interval in dfB. If this is true, then the two datasets should merge on a given column for that row. I'm not sure if the code I wrote will work w/o error, because the loop is still running.
Any insight would be appreciated.
dfA:
Common a Date
1 20141331123 1 2005-01-01
2 20141331123 2 2005-01-02
3 20141331123 3 2005-01-03
4 20141331123 4 2005-01-04
5 20141331123 5 2005-01-05
6 20141331123 6 2005-01-06
dfB:
cDate bDate common
1 2005-01-01 2005-06-13 20141331123
dfB$Interval <- interval(ymd(dfB$cDate), ymd(dfB$bDate))
library(lubridate)
for (i in 1:nrow(dfA)) {
for (i in 1:nrow(dfB)) {
if (dfA$Date[i] %within% dfB$Interval[i] == TRUE) {
merged <- merge(dfA, dfB, by.x = c("common"), by.y = c("Common"))
}
}
return(merged)
}

Non-equal joins are supported in SQL natively, and in data.table within R. Neither base R nor tidyverse functions support it locally[1].
library(data.table)
setDT(dfA)
setDT(dfB)
dfB[dfA, on = .(common == Common, cDate <= Date, bDate >= Date)]
# cDate bDate common a
# 1: 2005-01-01 2005-01-01 20141331123 1
# 2: 2005-01-02 2005-01-02 20141331123 2
# 3: 2005-01-03 2005-01-03 20141331123 3
# 4: 2005-01-04 2005-01-04 20141331123 4
# 5: 2005-01-05 2005-01-05 20141331123 5
# 6: 2005-01-06 2005-01-06 20141331123 6
The sample data is a little uninteresting in that everything fits in the single interval, but perhaps this will work with your more varied data.
[1]: Since SQL supports it, it's supported in dbplyr using sql_on.
Data:
dfA <- structure(list(Common = c("20141331123", "20141331123", "20141331123", "20141331123", "20141331123", "20141331123"), a = 1:6, Date = structure(c(12784, 12785, 12786, 12787, 12788, 12789), class = "Date")), row.names = c(NA, -6L), class = "data.frame")
dfB <- structure(list(cDate = structure(12784, class = "Date"), bDate = structure(12947, class = "Date"), common = "20141331123"), row.names = c(NA, -1L), class = "data.frame")

Consider a straightforward merge and subset if data size allows it.
final_df <- subset(merge(dfA, dfB, by.x="Common", by.y="common"),
Date >= cDate & Date <= bDate)
final_df
# Common a Date cDate bDate
# 1 20141331123 1 2005-01-01 2005-01-01 2005-06-13
# 2 20141331123 2 2005-01-02 2005-01-01 2005-06-13
# 3 20141331123 3 2005-01-03 2005-01-01 2005-06-13
# 4 20141331123 4 2005-01-04 2005-01-01 2005-06-13
# 5 20141331123 5 2005-01-05 2005-01-01 2005-06-13
# 6 20141331123 6 2005-01-06 2005-01-01 2005-06-13
Online Demo

Related

Creating intervals from time series data

I have a data frame of users and access times. Access times can be duplicated.
I am trying to create a list of users grouped and named by a given time interval, e.g. year.
timestamp user
1 2013-03-06 01:00:00 1
2 2014-07-06 21:00:00 1
3 2014-07-31 23:00:00 2
4 2014-08-09 17:00:00 2
5 2014-08-14 20:00:00 2
6 2014-08-14 22:00:00 3
7 2014-08-16 15:00:00 3
8 2014-08-19 02:00:00 1
9 2014-12-28 18:00:00 1
10 2015-01-17 17:00:00 1
11 2015-01-22 22:00:00 2
12 2015-01-22 22:00:00 3
13 2015-03-23 15:00:00 4
14 2015-04-05 18:00:00 1
15 2015-04-06 01:00:00 2
My code example already creates a list of users grouped by year.
My problem is that I need to modify the table in this approach, which becomes a problem with my tables of a million entries.
test <- structure(list(timestamp = c("2013-03-06 01:00:00", "2014-07-06 21:00:00",
"2014-07-31 23:00:00", "2014-08-09 17:00:00", "2014-08-14 20:00:00",
"2014-08-14 22:00:00", "2014-08-16 15:00:00", "2014-08-19 02:00:00",
"2014-12-28 18:00:00", "2015-01-17 17:00:00", "2015-01-22 22:00:00",
"2015-01-22 22:00:00", "2015-03-23 15:00:00", "2015-04-05 18:00:00",
"2015-04-06 01:00:00"), user = c(1L, 1L, 2L, 2L, 2L, 3L, 3L,
1L, 1L, 1L, 2L, 3L, 4L, 1L, 2L)), .Names = c("timestamp", "user"
), class = "data.frame", row.names = c(NA, -15L))
require(lubridate)
#Creating "POSIXct" object from string timestamp
timestamp <- lapply(test$timestamp,
function(x)parse_date_time(x, "y-m-d H:M:S"))
test$timestamp <- do.call(c,timestamp)
print(class(test$timestamp))
#Adding column for year
test <- cbind(test,sapply(timestamp, function(x)year(x)))
colnames(test)[3]<- "year"
#Creating list of year time intervals for users
intervals <- names(table(test$year))
users <- lapply(intervals, function(x)test[test$year %in% x,"user"])
names(users) <- intervals
without timestamps
treat the timestamp as a character. Only works if for every timestap, the first 4 digits represent the year.
library(dplyr)
test %>%
group_by( user, substr(timestamp,1,4 ) ) %>%
summarise( )
# user `substr(timestamp, 1, 4)`
# <int> <chr>
# 1 1 2013
# 2 1 2014
# 3 1 2015
# 4 2 2014
# 5 2 2015
# 6 3 2014
# 7 3 2015
# 8 4 2015
dplyr + lubridate
will extract the year from the timestamp
library( dplyr )
library( lubridate )
test %>%
mutate( timestamp = as.POSIXct( timestamp, format = "%Y-%m-%d %H:%M:%S" ) ) %>%
group_by( user, lubridate::year( timestamp ) ) %>%
summarise( )
# # Groups: user [?]
# user `year(timestamp)`
# <int> <dbl>
# 1 1 2013
# 2 1 2014
# 3 1 2015
# 4 2 2014
# 5 2 2015
# 6 3 2014
# 7 3 2015
# 8 4 2015
table
a frequency table is also quickly made
table( test$user, substr( test$timestamp, 1, 4 ) )
# 2013 2014 2015
# 1 1 3 2
# 2 0 3 2
# 3 0 2 1
# 4 0 0 1
there are any more alternatives... pick one
edit
if speed is an issue, ty data.table
dcast(
setDT( test )[, timestamp := as.POSIXct( timestamp, format = "%Y-%m-%d %H:%M:%S" )][, .N, by = list( user, data.table::year(timestamp) )],
user ~ data.table,
value.var = "N")
# user 2013 2014 2015
# 1: 1 1 3 2
# 2: 2 NA 3 2
# 3: 3 NA 2 1
# 4: 4 NA NA 1
Another option using the lightning fast data.table package:
library(data.table)
setDT(test) # make `test` a data.frame 'by reference' (no copy is made at all)
test[, j=.(users=list(unique(user))),
by=.(year=substr(test$timestamp,1,4))]
year users
1: 2013 1
2: 2014 1,2,3
3: 2015 1,2,3,4
Again assuming your test$timestamp column is a character vector - otherwise substitute lubridate::year() as needed.
Update:
Simple change to show grouping instead by month (just as it was mentioned in a comment):
test[, j=.(users=list(unique(user))),
by=.(ym=substr(test$timestamp,1,7))]
ym users
1: 2013-03 1
2: 2014-07 1,2
3: 2014-08 2,3,1
4: 2014-12 1
5: 2015-01 1,2,3
6: 2015-03 4
7: 2015-04 1,2
Or group by day, to help demonstrate how to subset with chaining:
test[, j=.(users=list(unique(user))),
by=.(ymd=substr(test$timestamp,1,11))][ymd>='2014-08-01' & ymd<= '2014-08-21']
ymd users
1: 2014-08-09 2
2: 2014-08-14 2,3
3: 2014-08-16 3
4: 2014-08-19 1
Note for filtering/subsetting, if you are only interested in a subset of dates for a "one off" calculation (and not otherwise saving the whole aggregated set to be stored for other purposes) it will likely be more efficient to do the subset in i of DT[i, j, by] for the "one off" calculation.
You could also use base (stats) function aggregate() as follows:
aggregate( x = test$user,
by = list(year=substr(test$timestamp,1,4)),
FUN = unique )
Result:
year x
1 2013 1
2 2014 1, 2, 3
3 2015 1, 2, 3, 4
Above working on assumption that your timestamp column is initially just a character vector exactly as included in your structured example data. In which case you may directly substr out the year with substr(test$timestamp,1,4) avoiding the need to first convert to dates.
However, if you have the timestamp column already as a date, simply substitute the lubridate::year() function you demonstrated in your attempted solution.

R: Create a New Column in R to determine Semester Based on Two Dates

I have some data. ID and date and I'm trying to create a new field for semester.
df:
id date
1 20160822
2 20170109
3 20170828
4 20170925
5 20180108
6 20180402
7 20160711
8 20150831
9 20160111
10 20160502
11 20160829
12 20170109
13 20170501
I also have a semester table:
start end season_year
20120801 20121222 Fall-2012
20121223 20130123 Winter-2013
20130124 20130523 Spring-2013
20130524 20130805 Summer-2013
20130806 20131228 Fall-2013
20131229 20140122 Winter-2014
20140123 20140522 Spring-2014
20140523 20140804 Summer-2014
20140805 20141227 Fall-2014
20141228 20150128 Winter-2015
20150129 20150528 Spring-2015
20150529 20150803 Summer-2015
20150804 20151226 Fall-2015
20151227 20160127 Winter-2016
20160128 20160526 Spring-2016
20160527 20160801 Summer-2016
20160802 20161224 Fall-2016
20161225 20170125 Winter-2017
20170126 20170525 Spring-2017
20170526 20170807 Summer-2017
20170808 20171230 Fall-2017
20171231 20180124 Winter-2018
20180125 20180524 Spring-2018
20180525 20180806 Summer-2018
20180807 20181222 Fall-2018
20181223 20190123 Winter-2019
20190124 20190523 Spring-2019
20190524 20180804 Summer-2019
I'd like to create a new field in df if df$date is between semester$start and semester$end, then place the respective value semester$season_year in df
I tried to see if the lubridate package could help but that seems to be more for calculations
I saw this question and it seems to be the closest to what i want, but, to make things more complicated, not all of our semesters are six months
Does this work?
library(lubridate)
semester$start <- ymd(semester$start)
semester$end <- ymd(semester$end)
df$date <- ymd(df$date)
LU <- Map(`:`, semester$start, semester$end)
LU <- data.frame(value = unlist(LU),
index = rep(seq_along(LU), lapply(LU, length)))
df$semester <- semester$season_year[LU$index[match(df$date, LU$value)]]
A solution using non-equi update joins using data.table and lubridate package can be as:
library(data.table)
setDT(df)
setDT(semester)
df[,date:=as.IDate(as.character(date), format = "%Y%m%d")]
semester[,':='(start = as.IDate(as.character(start), format = "%Y%m%d"),
end=as.IDate(as.character(end), format = "%Y%m%d"))]
df[semester, on=.(date >= start, date <= end), season_year := i.season_year]
df
# id date season_year
# 1: 1 2016-08-22 Fall-2016
# 2: 2 2017-01-09 Winter-2017
# 3: 3 2017-08-28 Fall-2017
# 4: 4 2017-09-25 Fall-2017
# 5: 5 2018-01-08 Winter-2018
# 6: 6 2018-04-02 Spring-2018
# 7: 7 2016-07-11 Summer-2016
# 8: 8 2015-08-31 Fall-2015
# 9: 9 2016-01-11 Winter-2016
# 10: 10 2016-05-02 Spring-2016
# 11: 11 2016-08-29 Fall-2016
# 12: 12 2017-01-09 Winter-2017
# 13: 13 2017-05-01 Spring-2017
Data:
df <- read.table(text="
id date
1 20160822
2 20170109
3 20170828
4 20170925
5 20180108
6 20180402
7 20160711
8 20150831
9 20160111
10 20160502
11 20160829
12 20170109
13 20170501",
header = TRUE, stringsAsFactors = FALSE)
semester <- read.table(text="
start end season_year
20120801 20121222 Fall-2012
20121223 20130123 Winter-2013
20130124 20130523 Spring-2013
20130524 20130805 Summer-2013
20130806 20131228 Fall-2013
20131229 20140122 Winter-2014
20140123 20140522 Spring-2014
20140523 20140804 Summer-2014
20140805 20141227 Fall-2014
20141228 20150128 Winter-2015
20150129 20150528 Spring-2015
20150529 20150803 Summer-2015
20150804 20151226 Fall-2015
20151227 20160127 Winter-2016
20160128 20160526 Spring-2016
20160527 20160801 Summer-2016
20160802 20161224 Fall-2016
20161225 20170125 Winter-2017
20170126 20170525 Spring-2017
20170526 20170807 Summer-2017
20170808 20171230 Fall-2017
20171231 20180124 Winter-2018
20180125 20180524 Spring-2018
20180525 20180806 Summer-2018
20180807 20181222 Fall-2018
20181223 20190123 Winter-2019
20190124 20190523 Spring-2019
20190524 20180804 Summer-2019",
header = TRUE, stringsAsFactors = FALSE)

Vectorising iterative operation across rows

I've seen a lot of questions on here about vectorising for loops, but couldn't find any that involve vectorising a for loop to populate a cell based on the value of a cell in a row below (apologies if I'm just being blind though...).
I have a dataframe with 1.6 million rows of salaries and the date each person started earning that salary. Each person can have multiple salaries, and so multiple rows, each with a different date that it was updated.
Code for a dummy dataset is as follows:
df1 <- data.frame("id" = c(1,1,2,2,3,3,4,4,5,5,6,6),
"salary" = c(15456,16594,
17364,34564,
34525,33656,
23464,23467,
16794,27454,
40663,42743),
"start_date" = sample(seq(as.Date('2016/01/01'),as.Date(Sys.Date()), by="day"), 12))
df1 <- df1[order(df1$id,df1$start_date),]
I want to create a column with an end date for each salary, which is calculated as the day before the subsequent salary entry. If there is no subsequent salary entry, then it's set as today's date. This is my code, including a for loop, to do that:
df1$end_date <- Sys.Date()
for (i in 1:(nrow(df1)-1)){
if(df1[i,1]== df1[i+1,1]){
df1[i,4] <- df1[i+1,3]-1
}
print(i)
}
However, I know that for loops are not the most efficient way, but how would I go about vectorising this?
Using the dplyr package, you could do:
library(dplyr)
df1 %>%
group_by(id) %>%
mutate(end_date=lead(start_date-1,default=Sys.Date()))
Which returns:
id salary start_date end_date
<dbl> <dbl> <date> <date>
1 1 15456 2016-02-14 2016-03-02
2 1 16594 2016-03-03 2017-05-22
3 2 17364 2016-01-17 2016-11-28
4 2 34564 2016-11-29 2017-05-22
5 3 33656 2016-08-17 2016-11-25
6 3 34525 2016-11-26 2017-05-22
7 4 23464 2016-01-20 2017-05-05
8 4 23467 2017-05-06 2017-05-22
9 5 27454 2016-02-29 2016-12-15
10 5 16794 2016-12-16 2017-05-22
11 6 42743 2016-03-14 2017-01-29
12 6 40663 2017-01-30 2017-05-22
You can use library(data.table):
setDT(df1)[, end_date := shift(start_date, type = "lead", fill = Sys.Date()), id][]
With data.table and shift, you can use below:
df1 <- data.table("id" = c(1,1,2,2,3,3,4,4,5,5,6,6),
"salary" = c(15456,16594,
17364,34564,
34525,33656,
23464,23467,
16794,27454,
40663,42743),
"start_date" = sample(seq(as.Date('2016/01/01'),as.Date(Sys.Date()), by="day"), 12))
df1 <- df1[order(id,start_date),]
df1[, EndDate := shift(start_date, type="lead"), id]
df1[is.na(EndDate), EndDate := Sys.Date()]
If I understand your question, the following base R code will work.
df1$end <- ave(df1$start_date, df1$id, FUN=function(x) c(tail(x, -1) - 1, Sys.Date()))
ave is used to perform the group level operation. The function performed takes the second through final date and subtracts 1. This is concatenated with the final date.
This returns
df1
id salary start_date end
1 1 15456 2016-03-20 2016-12-06
2 1 16594 2016-12-07 2017-05-22
3 2 17364 2016-10-17 2016-07-27
4 2 34564 2016-07-28 2017-05-22
5 3 34525 2016-05-26 2016-05-01
6 3 33656 2016-05-02 2017-05-22
7 4 23464 2017-04-17 2016-01-19
8 4 23467 2016-01-20 2017-05-22
9 5 16794 2016-09-12 2016-05-06
10 5 27454 2016-05-07 2017-05-22
11 6 40663 2016-10-03 2016-03-28
12 6 42743 2016-03-29 2017-05-22

Using a rolling time interval to count rows in R and dplyr

Let's say I have a dataframe of timestamps with the corresponding number of tickets sold at that time.
Timestamp ticket_count
(time) (int)
1 2016-01-01 05:30:00 1
2 2016-01-01 05:32:00 1
3 2016-01-01 05:38:00 1
4 2016-01-01 05:46:00 1
5 2016-01-01 05:47:00 1
6 2016-01-01 06:07:00 1
7 2016-01-01 06:13:00 2
8 2016-01-01 06:21:00 1
9 2016-01-01 06:22:00 1
10 2016-01-01 06:25:00 1
I want to know how to calculate the number of tickets sold within a certain time frame of all tickets. For example, I want to calculate the number of tickets sold up to 15 minutes after all tickets. In this case, the first row would have three tickets, the second row would have four tickets, etc.
Ideally, I'm looking for a dplyr solution, as I want to do this for multiple stores with a group_by() function. However, I'm having a little trouble figuring out how to hold each Timestamp fixed for a given row while simultaneously searching through all Timestamps via dplyr syntax.
In the current development version of data.table, v1.9.7, non-equi joins are implemented. Assuming your data.frame is called df and the Timestamp column is POSIXct type:
require(data.table) # v1.9.7+
window = 15L # minutes
(counts = setDT(df)[.(t=Timestamp+window*60L), on=.(Timestamp<t),
.(counts=sum(ticket_count)), by=.EACHI]$counts)
# [1] 3 4 5 5 5 9 11 11 11 11
# add that as a column to original data.table by reference
df[, counts := counts]
For each row in t, all rows where df$Timestamp < that_row is fetched. And by=.EACHI instructs the expression sum(ticket_count) to run for each row in t. That gives your desired result.
Hope this helps.
This is a simpler version of the ugly one I wrote earlier..
# install.packages('dplyr')
library(dplyr)
your_data %>%
mutate(timestamp = as.POSIXct(timestamp, format = '%m/%d/%Y %H:%M'),
ticket_count = as.numeric(ticket_count)) %>%
mutate(window = cut(timestamp, '15 min')) %>%
group_by(window) %>%
dplyr::summarise(tickets = sum(ticket_count))
window tickets
(fctr) (dbl)
1 2016-01-01 05:30:00 3
2 2016-01-01 05:45:00 2
3 2016-01-01 06:00:00 3
4 2016-01-01 06:15:00 3
Here is a solution using data.table. Also incorporating different stores.
Example data:
library(data.table)
dt <- data.table(Timestamp = as.POSIXct("2016-01-01 05:30:00")+seq(60,120000,by=60),
ticket_count = sample(1:9, 2000, T),
store = c(rep(c("A","B","C","D"), 500)))
Now apply the following:
ts <- dt$Timestamp
for(x in ts) {
end <- x+900
dt[Timestamp <= end & Timestamp >= x ,CS := sum(ticket_count),by=store]
}
This gives you
Timestamp ticket_count store CS
1: 2016-01-01 05:31:00 3 A 13
2: 2016-01-01 05:32:00 5 B 20
3: 2016-01-01 05:33:00 3 C 19
4: 2016-01-01 05:34:00 7 D 12
5: 2016-01-01 05:35:00 1 A 15
---
1996: 2016-01-02 14:46:00 4 D 10
1997: 2016-01-02 14:47:00 9 A 9
1998: 2016-01-02 14:48:00 2 B 2
1999: 2016-01-02 14:49:00 2 C 2
2000: 2016-01-02 14:50:00 6 D 6

Date Interval removal

I have data that looks like
ID CLM_ID Date1 Date2
1 718182 1/1/2014 1/17/2014
1 718184 1/2/2014 1/8/2014
1 885236 1/15/2014 1/17/2014
1 885362 3/20/2014 3/21/2014
2 589963 3/18/2015 3/22/2015
2 589999 2/27/2015 5/9/2015
2 594226 4/11/2015 4/17/2015
2 689959 5/10/2015 6/10/2015
3 656696 5/1/2016 5/5/2016
3 669625 5/6/2016 5/22/2016
4 777777 2/21/2015 3/4/2015
4 778952 2/1/2015 2/28/2015
4 778965 3/1/2015 3/22/2015
I am working on two different problems with this. The first one was answered in a previous post about how to roll dates up (Date roll-up in R) and the second now is that I have intervals that are within intervals and I am trying to get rid of them. So the final outcome should look like
ID CLM_ID Date1 Date2
1 718182 1/1/2014 1/17/2014
1 885362 3/20/2014 3/21/2014
2 589999 2/27/2015 5/9/2015
3 656696 5/1/2016 5/22/2016
4 778952 2/1/2015 3/22/2015
Now I know I will have to create the extended intervals via the date rollup first, but then how do I get rid of these sub-intervals (a term I am making up for intervals within intervals)? I am also looking for a solution that is efficient since I actually have 75,000 records to go through (i.e. I am trying to avoid iterative solutions).
Using non-equi joins from the current development version of data.table, v1.9.7,
require(data.table) # v1.9.7+
dt[dt, .(CLM_IDs = CLM_IDs[.N==1L]), on=.(ID, Date1<=Date1, Date2>=Date2), by=.EACHI]
# ID Date1 Date2 CLM_ID
# 1: 1 2014-01-01 2014-01-17 718182
# 2: 1 2014-03-20 2014-03-21 885362
# 3: 2 2015-02-27 2015-05-09 589999
# 4: 2 2015-05-10 2015-06-10 689959
# 5: 3 2016-05-01 2016-05-05 656696
# 6: 3 2016-05-06 2016-05-22 669625
# 7: 4 2015-02-21 2015-03-04 777777
# 8: 4 2015-02-01 2015-02-28 778952
# 9: 4 2015-03-01 2015-03-22 778965
What this does is, for each row in dt (the one inside of square bracket), it looks up which rows match in dt (on the outside) based on the condition provided to the on argument.
The matching row indices are returned iff the only match is a self-match (since the condition includes equality as well). This is done by CLM_IDs[.N == 1L], where .N holds the number of observations for each group.
"I am also looking for a solution that is efficient ... (i.e. I am trying to avoid iterative solutions)."
"Your assumptions are your windows on the world. Scrub them off every once in a while, or the light won't come in." - Isaac Asimov
Below is a super fast base R iterative solution. It returns the correct results for very large data frames virtually instantly. (it also "rolls-up" the data, so there is no need to carry out two algorithms):
MakeDFSubInt <- function(df, includeCost = FALSE) {
## Sorting the data frame to allow for fast
## creation of the "Contained" logical vector below
tempDF <- df[order(df$ID, df$Date1, df$Date2), ]
UniIDs <- unique(tempDF$ID)
Len <- length(UniIDs)
## Determine starting (i.e. "s") and ending (i.e. "e")
## points of the respective groups of IDs
e <- which(diff(tempDF$ID)==1)
s <- c(1L, e + 1L)
dfLen <- nrow(tempDF)
e <- c(e, dfLen)
## Converting dates to integers so that comparison
## will be faster. Internally dates are stored as
## integers, so this isn't a problem
dte1 <- as.integer(tempDF$Date1)
dte2 <- as.integer(tempDF$Date2)
## Building logical vector in order to quickly create sub-intervals
Contained <- rep(FALSE, dfLen)
BegTime <- Sys.time() ## Included to measure time of for loop execution
for (j in 1:Len) {
Compare <- ifelse(dte2[s[j]] >= (dte1[s[j]+1L]+1L), max(dte2[s[j]], dte2[s[j]+1L]), dte2[s[j]+1L])
for (x in (s[j]+1L):e[j]) {
if (!Contained[x-1L]) {
Contained[x] <- dte2[x-1L] >= (dte1[x]-1L)
} else {
Contained[x] <- Compare >= (dte1[x]-1L)
}
## could use ifelse, but this construct is faster
if (Contained[x]) {
Compare <- max(Compare, dte2[x])
} else {
Compare <- dte2[x]
}
}
}
EndTime <- Sys.time()
TotTime <- EndTime - BegTime
if (printTime) {print(paste(c("for loop execution time was: ", format(TotTime)), collapse = ""))}
## identify sub-intervals
nGrps <- which(!Contained)
## Create New fields for our new DF
ID <- tempDF$ID[nGrps]
CLM_ID <- tempDF$CLM_ID[nGrps]
Date1 <- tempDF$Date1[nGrps]
nGrps <- c(nGrps, dfLen+1L)
## as.Date is converting numbers to dates.
## N.B. This only works if origin is supplied
Date2 <- as.Date(vapply(1L:(length(nGrps) - 1L), function(x) {
max(dte2[nGrps[x]:(nGrps[x+1L]-1L)])}, 1L), origin = "1970-01-01")
## in a related question the OP had, "Cost" was
## included to show how the algorithm would handle
## generic summary information
if (includeCost) {
myCost <- tempDF$Cost
Cost <- vapply(1L:(length(nGrps) - 1L), function(x) sum(myCost[nGrps[x]:(nGrps[x+1L]-1L)]), 100.01)
NewDf <- data.frame(ID,CLM_ID,Date1,Date2,Cost)
} else {
NewDf <- data.frame(ID,CLM_ID,Date1,Date2)
}
NewDf
}
For the example given in the question, we have:
ID <- c(rep(1,4),rep(2,4),rep(3,2),rep(4,3))
CLM_ID <- c(718182, 718184, 885236, 885362, 589963, 589999, 594226, 689959, 656696, 669625, 777777, 778952, 778965)
Date1 <- c("1/1/2014","1/2/2014","1/15/2014","3/20/2014","3/18/2015","2/27/2015","4/11/2015","5/10/2015","5/1/2016","5/6/2016","2/21/2015","2/1/2015","3/1/2015")
Date2 <- c("1/17/2014","1/8/2014","1/17/2014","3/21/2014","3/22/2015","5/9/2015","4/17/2015","6/10/2015","5/5/2016","5/22/2016","3/4/2015","2/28/2015","3/22/2015")
myDF <- data.frame(ID, CLM_ID, Date1, Date2)
myDF$Date1 <- as.Date(myDF$Date1, format = "%m/%d/%Y")
myDF$Date2 <- as.Date(myDF$Date2, format = "%m/%d/%Y")
MakeDFSubInt(myDF)
ID CLM_ID Date1 Date2
1 1 718182 2014-01-01 2014-01-17
2 1 885362 2014-03-20 2014-03-21
3 2 589999 2015-02-27 2015-06-10
4 3 656696 2016-05-01 2016-05-22
5 4 778952 2015-02-01 2015-03-22
From a similar question the OP posted, we can add a Cost field, to show how we would proceed with calculations for this setup.
set.seed(7777)
myDF$Cost <- round(rnorm(13, 450, sd = 100),2)
MakeDFSubInt(myDF, includeCost = TRUE)
ID CLM_ID Date1 Date2 Cost
1 1 718182 2014-01-01 2014-01-17 1164.66
2 1 885362 2014-03-20 2014-03-21 568.16
3 2 589999 2015-02-27 2015-06-10 2019.16
4 3 656696 2016-05-01 2016-05-22 990.14
5 4 778952 2015-02-01 2015-03-22 1578.68
This algorithm scales very well. For data frames the size the OP is looking for, returning the requested DF returns almost instantaneously and for very large data frames, it returns in just seconds.
First we build a function that will generate a random data frame with n rows.
MakeRandomDF <- function(n) {
set.seed(109)
CLM_Size <- ifelse(n < 10^6, 10^6, 10^(ceiling(log10(n))))
numYears <- trunc((6/425000)*n + 5)
StrtYear <- ifelse(numYears > 16, 2000, 2016 - numYears)
numYears <- ifelse(numYears > 16, 16, numYears)
IDs <- sort(sample(trunc(n/100), n, replace = TRUE))
CLM_IDs <- sample(CLM_Size, n)
StrtDate <- as.Date(paste(c(as.character(StrtYear),"-01-01"), collapse = ""))
myPossibleDates <- StrtDate+(0:(numYears*365)) ## "numYears" years of data
Date1 <- sample(myPossibleDates, n, replace = TRUE)
Date2 <- Date1 + sample(1:100, n, replace = TRUE)
Cost <- round(rnorm(n, 850, 100), 2)
tempDF <- data.frame(IDs,CLM_IDs,Date1,Date2,Cost)
tempDF$Date1 <- as.Date(tempDF$Date1, format = "%m/%d/%Y")
tempDF$Date2 <- as.Date(tempDF$Date2, format = "%m/%d/%Y")
tempDF
}
For moderate size DFs (i.e. 75,000 rows)
TestDF <- MakeRandomDF(75000)
system.time(test1 <- MakeDFSubInt(TestDF, includeCost = TRUE, printTime = TRUE))
[1] "for loop execution time was: 0.06500006 secs"
user system elapsed
0.14 0.00 0.14
nrow(test1)
[1] 7618
head(test1)
ID CLM_ID Date1 Date2 Cost
1 1 116944 2010-01-29 2010-01-30 799.90 ## The range of dates for
2 1 515993 2010-02-15 2011-10-12 20836.83 ## each row are disjoint
3 1 408037 2011-12-13 2013-07-21 28149.26 ## as requested by the OP
4 1 20591 2013-07-25 2014-03-11 10449.51
5 1 338609 2014-04-24 2014-07-31 4219.48
6 1 628983 2014-08-03 2014-09-11 2170.93
For very large DFs (i.e. > 500,000 rows)
TestDF2 <- MakeRandomDF(500000)
system.time(test2 <- MakeDFSubInt(TestDF2, includeCost = TRUE, printTime = TRUE))
[1] "for loop execution time was: 0.3679998 secs"
user system elapsed
1.19 0.03 1.21
nrow(test2)
[1] 154839
head(test2)
ID CLM_ID Date1 Date2 Cost
1 1 71251 2004-04-19 2004-06-29 2715.69 ## The range of dates for
2 1 601676 2004-07-05 2004-09-23 2675.04 ## each row are disjoint
3 1 794409 2004-12-28 2005-04-05 1760.63 ## as requested by the OP
4 1 424671 2005-06-03 2005-08-20 1973.67
5 1 390353 2005-09-16 2005-11-06 785.81
6 1 496611 2005-11-21 2005-11-24 904.09
system.time(test3 <- MakeDFSubInt(TestDF3, includeCost = TRUE, printTime = TRUE))
[1] "for loop execution time was: 0.6930001 secs"
user system elapsed
2.68 0.08 2.79 ## 1 million rows in under 3 seconds!!!
nrow(test3)
[1] 413668
Explanation
The main part of the algorithm is generating the Contained logical vector that is used to determine the sub-intervals of continuous dates. Generation of this vector relies on the fact that the data frame is sorted, first by ID, second by Date1, and finally by Date2. We begin by locating the starting and ending rows of each group of IDs. For example, with the example provided by the OP we have:
myDF
ID CLM_ID Date1 Date2
1 1 718182 2014-01-01 2014-01-17 ## <- 1 s[1]
2 1 718184 2014-01-02 2014-01-08
3 1 885236 2014-01-15 2014-01-17
4 1 885362 2014-03-20 2014-03-21 ## <- 4 e[1]
5 2 589963 2015-03-18 2015-03-22 ## <- 5 s[2]
6 2 589999 2015-02-27 2015-05-09
7 2 594226 2015-04-11 2015-04-17
8 2 689959 2015-05-10 2015-06-10 ## <- 8 e[2]
9 3 656696 2016-05-01 2016-05-05 ## <- 9 s[3]
10 3 669625 2016-05-06 2016-05-22 ## <- 10 e[3]
11 4 777777 2015-02-21 2015-03-04 ## <- 11 s[4]
12 4 778952 2015-02-01 2015-02-28
13 4 778965 2015-03-01 2015-03-22 ## <- 13 e[4]
Below is the code that generates s and e.
## Determine starting (i.e. "s") and ending (i.e. "e")
## points of the respective groups of IDs
e <- which(diff(tempDF$ID)==1)
s <- c(1L, e + 1L)
dfLen <- nrow(tempDF)
e <- c(e, dfLen)
s
1 5 9 11
e
4 8 10 13
Now, we loop over each group and begin populating the logical vector Contained. If the date range for a particular row overlaps (or is a continuance of) the date range above it, we set that particular index of Contained to TRUE. This is why the first row in each group is set to FALSE since there is nothing above to compare it to. As we are doing this, we are updating the largest date to compare against moving forward, hence the Compare variable. It should be noted that it isn't necessarily true that Date2[n] < Date2[n+1L], this is why Compare <- max(Compare, dte2[x]) for a succession of TRUEs. The result for our example is give below.
ID CLM_ID Date1 Date2 Contained
1 1 718182 2014-01-01 2014-01-17 FALSE
2 1 718184 2014-01-02 2014-01-08 TRUE ## These two rows are contained
3 1 885236 2014-01-15 2014-01-17 TRUE ## in the date range 1/1 - 1/17
4 1 885362 2014-03-20 2014-03-21 FALSE ## This row isn't
6 2 589999 2015-02-27 2015-05-09 FALSE
5 2 589963 2015-03-18 2015-03-22 TRUE
7 2 594226 2015-04-11 2015-04-17 TRUE
8 2 689959 2015-05-10 2015-06-10 TRUE ## N.B. 5/10 is a continuance of 5/09
9 3 656696 2016-05-01 2016-05-05 FALSE
10 3 669625 2016-05-06 2016-05-22 TRUE
12 4 778952 2015-02-01 2015-02-28 FALSE
11 4 777777 2015-02-21 2015-03-04 TRUE
13 4 778965 2015-03-01 2015-03-22 TRUE
Now we can easily identify the "starting" rows by identifying all rows with a corresponding FALSE. After this, finding summary information is a breeze by simply calculating whatever you are interested in (e.g. max(Date2), sum(Cost)) over each succession of TRUEs and Voila!!
Here is a not-so-pretty solution comparing each row with the dates of all other rows. I corrected the one year 3015 to 2015. The results are different from what you are expecting, though. Either I misunderstood your question, or you misread the data.
Data:
dta <- structure(list(ID = c(1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 3L, 3L, 4L, 4L, 4L),
CLM_ID = c(718182L, 718184L, 885236L, 885362L, 589963L, 589999L, 594226L, 689959L, 656696L, 669625L, 777777L, 778952L, 778965L),
Date1 = structure(c(1L, 3L, 2L, 9L, 8L, 6L, 10L, 12L, 11L, 13L, 5L, 4L, 7L), .Label = c("1/1/2014", "1/15/2014", "1/2/2014", "2/1/2015", "2/21/2015", "2/27/2015", "3/1/2015", "3/18/2015", "3/20/2014", "4/11/2015", "5/1/2016", "5/10/2015", "5/6/2016"), class = "factor"),
Date2 = structure(c(1L, 2L, 1L, 4L, 5L, 10L, 7L, 11L, 9L, 8L, 6L, 3L, 5L), .Label = c("1/17/2014", "1/8/2014", "2/28/2015", "3/21/2014", "3/22/2015", "3/4/2015", "4/17/2015", "5/22/2016", "5/5/2016", "5/9/2015", "6/10/2015"), class = "factor")),
.Names = c("ID", "CLM_ID", "Date1", "Date2"), class = "data.frame",
row.names = c(NA, -13L))
Code:
dta$Date1 <- as.Date(dta$Date1, format = "%m/%d/%Y")
dta$Date2 <- as.Date(dta$Date2, format = "%m/%d/%Y")
# Boolean vector to memorize results
keep <- logical(length = nrow(dta))
for(i in 1:nrow(dta)) {
match <- dta[dta$Date1 <= dta$Date1[i] & dta$Date2 >= dta$Date2[i], ]
if(nrow(match) == 1) keep[i] <- TRUE
}
# Result
dta[keep, ]

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