CODEWITHSUNDEEP
rdataframetime-seriestidyverserandom-data
Hydro
Hydro

Reputation: 1117

How to construct a random data set of different year in R?

The code below will generate uniformly distributed data at a daily time step for the year 2009. Suppose, i want to construct a similar data set which would include the year 2009,2012, 2015, and 2019, how would i do that?. I am basically trying to avoid repeating the code or using filter to grab data for the year of interest.

library(tidyverse)
library(lubridate)

set.seed(500)
DF1 <- data.frame(Date = seq(as.Date("2009-01-01"), to = as.Date("2009-12-31"), by = "day"),
                  Flow = runif(365,20,60))

Upvotes: 1

Views: 78

Answers (2)

akrun
akrun

Reputation: 887711

Here is an option where we create a vector of year, loop over the vector, get the sequence of dates after converting to Date class and create the 'Flow' from uniform distribution

year <- c(2009, 2012, 2015, 2019)
lst1 <- lapply(year, function(yr) {
     dates <- seq(as.Date(paste0(yr, '-01-01')), 
                  as.Date(paste0(yr, '-12-31')), by = 'day')
     data.frame(Date = dates, 
      Flow= runif(length(dates), 20, 60))
   })

and create a single data.frame with do.call

dat1 <- do.call(rbind, lst1)

Upvotes: 1

slava-kohut
slava-kohut

Reputation: 4233

Here is a possible solution:

set.seed(123)
sample_size <- 1000

y <- sample(c(2009,2012,2015,2019),sample_size,replace=TRUE)
simulate_date <- function(year){
  n_days <- ifelse(lubridate::leap_year(year),
                   366,365)
  as.Date(sample(1:n_days, 1), origin=paste0(year,"-01-01"))
}

dates <- Reduce(`c`, purrr::map(y, simulate_date))

> head(dates)
[1] "2012-06-28" "2012-01-15" "2009-07-15" "2012-11-02" "2019-04-29"
[6] "2015-10-27"

Upvotes: 1

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