so I am trying to look at day of year that ice is freezing in lakes over time.
I have figured out how to convert my dates into Julian days, however, in some years ice-on is happening in the same year.
eg. lake froze on January 3rd 2014 (which actually represents the year 2013) and the same lake froze December 28th 2014.
So when I convert into Julian dates, that years Julian day is represented by "3". But I need a lake that froze on January 3rd 2014 to be represented by 365 + 3 = 368.
Is there a way I can do this in RStudio? Any help is appreciated.
This is what my data frame (frame1) currently looks like
I cannot seem to find anything online to solve this issue. Here is the code I've used to get to this point.
library(readxl)
library(here)
library(janitor)
library(tidyverse)
library(dplyr)
library(lubridate)
frame1 <- readxl::read_excel(here('data/Syke IB 1800-2022 (1).xlsx'), sheet = 2) %>%
clean_names() %>%
select(date, lippu) %>%
mutate(year= year(date),
month = month(date),
day = day(date)) %>%
filter(lippu == "x7" )
frame1$MY.DATE1 <- do.call(paste, list(frame1$year, frame1$month, frame1$day)) %>%
frame1$MY.DATE1 <- as.Date(frame1$MY.DATE1, format=c("%Y %m %d")) %>%
frame1$my.julian.date <- as.numeric(format(frame1$MY.DATE1, "%j")) %>%
frame1