I'm working with a simple dataset. It contains three variables of interest. 1. Date YYYY-MM-DD 2. Hourly (##) 3. Precip_H (#.##).
My situation is that I am trying to find code that will for example, sum the precip_H values across rows that are equal to a specific DATE and are within 00-11 for the value of Hourly. Then the next set would do all the same but for 12-23 range in Hourly.
This dataset is a weather station that reports precipitation hourly. What I am trying to do is use that information to make two 12 hour precipitation values per day across all days of the dataset.
   DATE       TIME  PRECIP_H DATEyyyy DATEmm DATEdd
   <date>     <chr>    <dbl>    <dbl>  <dbl>  <dbl>
 1 2019-06-05 17           0     2019      6      5
 2 2019-06-01 20           0     2019      6      1
 3 2019-06-06 19           0     2019      6      6
 4 2019-05-27 00           0     2019      5     27
 5 2019-08-25 20           0     2019      8     25
 6 2019-08-08 04           0     2019      8      8
 7 2019-09-01 07           0     2019      9      1
 8 2019-07-18 21           0     2019      7     18
 9 2019-06-18 23           0     2019      6     18
10 2019-08-11 12           0     2019      8     11
library(readxl)
precip2019 <- Clean_Chicago_Midway_Precp_Hourly_2019_1945790 <- read_excel("S:/Natural Resources/Staff/Beach Management/Beaches Main/+ DATA ANALYSIS +/Beaches 2019/Master Files/Clean_Chicago Midway Precp Hourly 2019_1945790.xlsx")
names(precip2019)[names(precip2019) == "HourlyPrecipitation"] <- "PRECIP_H"
precip2019$DATE <- as.Date(precip2019$DATE, format = '%Y-%m-%d')
precip2019$DATEyyyy <- as.numeric(format(precip2019$DATE, '%Y'))
precip2019$DATEmm <- as.numeric(format(precip2019$DATE, '%m'))
precip2019$DATEdd <- as.numeric(format(precip2019$DATE, '%d'))
prec_sum <- precip2019 %>% 
  select(DATE, TIME, starts_with("PREC")) %>% 
  mutate(Period = case_when(between(TIME, 0, 11) ~ "1st_half",
                            TRUE ~ "2nd_half")) %>% 
  group_by(DATE, Period) %>% 
  summarise_at(vars(starts_with("PREC")), list(~ sum(., na.rm = TRUE))) %>% 
  ungroup()
View(prec_sum) 
 
    