# INBO CODING CLUB
27 October 2020

Welcome!

## Share your code snippet

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As an **example**:

library(tidyverse)

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## Yellow sticky notes

No yellow sticky notes online. Put your name + " | " and add a "*" each time you solve a challenge (see below).

## Participants

Name | Challenges
--- | ---
Damiano Oldoni |
Dirk Maes |
Joost Vanoverbeke | **
Hans Van Calster | **
Emma Cartuyvels |**
Suzanna Lettens |
Lynn Pallemaerts | **
Jim Casaer |

# Tips and tricks

It's always good to know which parsing format lubridate uses. You get to know it by
typing `options(lubridate.verbose = TRUE)` in your console once.

## Challenge 1

### Solution Dirk 1.1

datetimes_to_parse$datetime1c <- ymd_hms(datetimes_to_parse$datetime1)
datetimes_to_parse$datetime2c <- ydm_hms(datetimes_to_parse$datetime2)
datetimes_to_parse$datetime3c <- dmy_hm(datetimes_to_parse$datetime3)

Emma:

#1
datetimes_to_parse <- datetimes_to_parse ymd_hms
  mutate(datetime1 = ymd_hms(datetime1),
  datetime2 = ydm_hms(datetime2),
  datetime3 = dmy_hm(datetime3))

#2
wday(c("2006-04-01","1985-07-17", "1991-03-13"), label = TRUE)

#3
sf <- stamp("The institute was founded on Monday, Jan 14, 1999",
            locale = "English")
sf(ymd("2006-04-01"))
sf(ymd("1985-07-17"))
sf(ymd("1991-03-13"))

#4
difftime(ymd("1985-07-17"), ymd("2006-04-01"))
difftime("2006-04-01", "1991-03-13")

Joost:

#2
INBO_dates <- tibble(instituut = c("INBO", "IN", "IBW"),
                     datum = c("2006-04-01", "1985-07-17", "1991-03-13")) %>%
  mutate(datum = ymd(datum),
         dag = wday(datum,
                    label = TRUE,
                    abbr = FALSE,
                    week_start = 1))

#3
stmp <- stamp_date("Het instituut werd opgericht op maandag, 1 januari, 1900")
INBO_dates %>%
  pull(datum) %>%
  stmp()

#of iets fancier
INBO_dates %>%
  {map2(.$instituut, .$datum, 
        function(x,y) 
          stamp(paste("Het instituut", x, "werd opgericht op maandag, 1 januari, 1900"))(y))}

## INTERMEZZO

UTC is the time standard and it is therefore used by default when defining a datetime

time_in_utc <- ymd_hms("2020-10-27 10:00:00")
time_in_utc

Showing differences between intervals and periods while daylight saving occurs:

start_datetime <- as_datetime("2020-10-25 01:00:00", tz = "CET")
# add a period (periods ignore time line irregularities)
start_datetime + hours(2)
# add a duration (track track the passage of physical time)
start_datetime + dhours(2)

end_datetime <- as_datetime("2020-10-25 03:00:00", tz = "CET")
end_datetime - start_datetime

**Periods** follow the everyday clock (with irregularities such as Daylight Saving Time), durations not as **durations** track the passage of physical time.

## Challenge 2

Joost
noot: om DST te verwijderen van tijd in CET
(vb langdurende tijdreeksen in CET **zonder** zomertijd)

as_datetime("2020-08-01 09:00:00", tz = "CET")
as_datetime("2020-08-01 09:00:00", tz = "CET") %>% with_tz("Etc/GMT-1")

as_datetime("2020-11-01 09:00:00", tz = "CET")
as_datetime("2020-11-01 09:00:00", tz = "CET") %>% with_tz("Etc/GMT-1")

Hans

# challenge 2.1
data_cameratrap <-
  data_cameratrap %>%
  mutate(image_sequence_datetime = as_datetime(image_sequence_datetime,
                                               tz = "EET"))

# challenge 2.2

data_cameratrap <-
  data_cameratrap %>%
  mutate(camera_deployment_start = with_tz(camera_deployment_start,
  tzone = "EET"),
         camera_deployment_end = with_tz(camera_deployment_end,
         tzone = "EET"))

Emma:

data_cameratrap <- data_cameratrap %>% 
  mutate(image_sequence_datetime = as_datetime(image_sequence_datetime,
                                           tz = "Europe/Kiev"))


# CHALLENGE 2.2

data_cameratrap <-
  data_cameratrap %>%
  mutate(camera_deployment_start = force_tz(camera_deployment_start,
                                           tzone = "Europe/Kiev"),
         camera_deployment_end = force_tz(camera_deployment_end,
                                         tzone = "Europe/Kiev"))

## Challenge 3

Hans

data_cameratrap <- data_cameratrap %>%
  pivot_longer(cols = where(is.POSIXct),
               names_to = "datevariables",
               values_to = "datetimes") %>%
  mutate(hour = hour(datetimes),
         day = day(datetimes))