Column operators regarding only specific columns (specific dates and code i.e.) in R - r

i am trying to calculate the average_relative_humidity of the city Seoul for the dates 2020-01-01 tll 2020-31-01.
I have this data:
and I´ve tried this already but don´t really know what´missing.
Seoul_weather_dt <- Corona_relevant_weather_dt[, avg_relative_humidity_seoul := mean(avg_relative_humidity[code =="2020-01-01":"2020-01-01"]), by = c("province", "date", "avg_temp", "avg_relative_humidity"]
Can someone help me?


Something like this?
#select only Seoul and relevant dates
Seoul_weather_dt <- Corona_relevant_weather_dt[province == "Seoul" & date > as.date("2020-01-01") & date <= as.date("2020-31-01")]
#calculate average humidity for each unique date
aggregate(Seoul_weather_dt$avg_relative_humidity, by = list(Seoul_weather_dt$date), FUN = mean)
The line of code you provide is pretty long. I would suggest creating multiple lines with less functions per line to maintain an overview (also easier when getting an error). Also
is datein class "Date"? You can see that using str(Seoul_weather_dt)
code =="2020-01-01":"2020-01-01" only selects one day
Using by = c("province", "date", "avg_temp", "avg_relative_humidity") is strange. Then you would calculate a mean value for each observation of avg_relative_humidity as well, which is not what you want
Why create average values for each province when you are only interested in Seoul?

Related

How to create a ''for loop'' to download 5 consecutive months of data?

For an assignment we are supposed to use a for-loop to obtain a dataframe of 5 consecutive months.
The data regards crimes and their accompanying type of crime, location, month, street name etc.
How do we go about this issue?
We use the package 'ukpolice' and use this code to obtain data for a specific month and location of choice;
ukpolice syntax is as follows:
data <- as.data.frame(ukc_crime_location(lat = , lng = , date = ""))
Thank you in advance!

R function for finding difference of dates with exceptions?

I was wondering if there was a function for finding the difference between and issue date and a maturity date, but with 2 maturity date. For example, I want to prioritize the dates in maturity date source 1 and subtract it from the issue date to find the difference. Then, if my dataset is missing dates from maturity date source 1, such as in lines 5 & 6, I want to use dates from maturity date source 2 to fill in the rest. I have tried the code below, but am unsure how to incorporate the data from maturity date source 2 without changing everything else. I have attached a picture for reference. Thank you in advance.
df$Maturity_Date_source_1 <- as.Date(c(df$Maturity_Date_source_1))
df$Issue_Date <- as.Date(c(df$Issue_Date))
df$difference <- (df$Maturity_Date_source_1 - df$Issue_Date) / 365.25
df$difference <- as.numeric(c(df$difference))

An option would be to coalesce the columns and then do the difference
library(dplyr)
df %>%
mutate(difference = as.numeric((coalesce(Maturity_Date_source_1,
Maturity_Date_source_2) - Issue_Date)/365.25))

Earliest date by country using R

I have a list of countries with the cumulative amount of cases (csum colum) by date in my dataframe (df)
I am trying to group by country and pull out the earliest date per country.
I tried the following code, but the dates it returns are incorrect:
df_2 = aggregate(df$date, by = list(df$country), FUN = "min")
Would anyone be able to see where i'm going wrong (p.s: I need to avoid using any libraries)
Thanks :)

Different age calculation for different rows

I'm an absolute R beginner here working on a Master's project.
I have a data.frame that contains information on trotting horses (their wins, earnings, time records and such). The data is organised in a way that every row contains information for a specific year the horse competed and including a first row for each horse of "Total", so there's a summary for every variable for it's total competing life. It looks like this:
I created a new variable with their age using the age_calc function in the eeptools package:
travdata$Age<-age_calc(as.Date(travdata$Birth.date), enddate=as.Date("2016-12-31"),
units="years")
With no problems. What I'm trying to figure out is if there is any way I can calculate the age of the horses for each specific year I have info on them-that is, the "Total" row would have their age up until 2016-12-31, for the year 2015 it would have their age at that time and so on. I've been trying to include if statements in age_calc but it won't work and I'm really at a loss on how best to do this.
Any literature or help you could point me to would be much, much appreciated.
MWE
travdata <- data.frame(
"Id.Number"=c(rep("1938-98",3),rep("1803-97",7),rep("1221-03",4)),
"Name"=c(rep("Muuttuva",3),rep("Pelson Poika",7),rep("Muusan Muisto",4)),
"Sex"=c(rep("Mare",3),rep("Gelding",7),rep("Gelding",4)),
"Birth.year"=c(rep(1998,3),rep(1997,7),rep(2003,4)),
"Birth.date"=c(rep("1998-07-01",3),rep("1997-07-14",7),rep("2003-05-07",4)),
"Competition.year" = c("Total",2005,2004,"Total",2003,2004,2006,2005,2002,2001,2008,2010,"Total",2009),
"starts"=c(20,11,9,44,21,6,7,5,3,2,1,1,4,2),
"X1st.placements"=c(0,0,0,3,3,0,0,0,0,0,0,0,0,0),
"X2nd.placements"=c(2,2,0,1,0,1,0,0,0,0,0,0,0,0),
"X3rd.placements"=c(2,2,0,1,1,0,0,0,0,0,0,0,0,0),
"Earnings.euro"=c(1525,1425,100,2078,1498,580,0,0,0,0,0,0,10,10)
)

The trick is to filter out the "Total" rows and specify a format for the as.Date() function
library(eeptools)
travdata <- data.frame(
"Id.Number"=c(rep("1938-98",3),rep("1803-97",7),rep("1221-03",4)),
"Name"=c(rep("Muuttuva",3),rep("Pelson Poika",7),rep("Muusan Muisto",4)),
"Sex"=c(rep("Mare",3),rep("Gelding",7),rep("Gelding",4)),
"Birth.year"=c(rep(1998,3),rep(1997,7),rep(2003,4)),
"Birth.date"=c(rep("1998-07-01",3),rep("1997-07-14",7),rep("2003-05-07",4)),
"Competition.year" = c("Total",2005,2004,"Total",2003,2004,2006,2005,2002,2001,2008,2010,"Total",2009),
"starts"=c(20,11,9,44,21,6,7,5,3,2,1,1,4,2),
"X1st.placements"=c(0,0,0,3,3,0,0,0,0,0,0,0,0,0),
"X2nd.placements"=c(2,2,0,1,0,1,0,0,0,0,0,0,0,0),
"X3rd.placements"=c(2,2,0,1,1,0,0,0,0,0,0,0,0,0),
"Earnings.euro"=c(1525,1425,100,2078,1498,580,0,0,0,0,0,0,10,10)
)
travdata$Age<-age_calc(as.Date(travdata$Birth.date),
enddate=as.Date("2016-12-31"), units="years")
competitions <- travdata[travdata$Competition.year!="Total",]
competitions$Competition.age<-age_calc(
as.Date(competitions$Birth.date),
enddate=as.Date(competitions$Competition.year, format="%Y"),
units="years",F)

How to match dates in 2 data frames in R, then sum specific range of values up to that date?

I have two data frames: rainfall data collected daily and nitrate concentrations of water samples collected irregularly, approximately once a month. I would like to create a vector of values for each nitrate concentration that is the sum of the previous 5 days' rainfall. Basically, I need to match the nitrate date with the rain date, sum the previous 5 days' rainfall, then print the sum with the nitrate data.
I think I need to either make a function, a for loop, or use tapply to do this, but I don't know how. I'm not an expert at any of those, though I've used them in simple cases. I've searched for similar posts, but none get at this exactly. This one deals with summing by factor groups. This one deals with summing each possible pair of rows. This one deals with summing by aggregate.
Here are 2 example data frames:
# rainfall df
mm<- c(0,0,0,0,5, 0,0,2,0,0, 10,0,0,0,0)
date<- c(1:15)
rain <- data.frame(cbind(mm, date))
# b/c sums of rainfall depend on correct chronological order, make sure the data are in order by date.
rain[ do.call(order, list(rain$date)),]
# nitrate df
nconc <- c(15, 12, 14, 20, 8.5) # nitrate concentration
ndate<- c(6,8,11,13,14)
nitrate <- data.frame(cbind(nconc, ndate))
I would like to have a way of finding the matching rainfall date for each nitrate measurement, such as:
match(nitrate$date[i] %in% rain$date)
(Note: Will match work with as.Date dates?) And then sum the preceding 5 days' rainfall (not including the measurement date), such as:
sum(rain$mm[j-6:j-1]
And prints the sum in a new column in nitrate
print(nitrate$mm_sum[i])
To make sure it's clear what result I'm looking for, here's how to do the calculation 'by hand'. The first nitrate concentration was collected on day 6, so the sum of rainfall on days 1-5 is 5mm.
Many thanks in advance.

You were more or less there!
nitrate$prev_five_rainfall = NA
for (i in 1:length(nitrate$ndate)) {
day = nitrate$ndate[i]
nitrate$prev_five_rainfall[i] = sum(rain$mm[(day-6):(day-1)])
}
Step by step explanation:
Initialize empty result column:
nitrate$prev_five_rainfall = NA
For each line in the nitrate df: (i = 1,2,3,4,5)
for (i in 1:length(nitrate$ndate)) {
Grab the day we want final result for:
day = nitrate$ndate[i]
Take the rainfull sum and it put in in the results column
nitrate$prev_five_rainfall[i] = sum(rain$mm[(day-6):(day-1)])
Close the for loop :)
}
Disclaimer: This answer is basic in that:
It will break if nitrate's ndate < 6
It will be incorrect if some dates are missing in the rain dataframe
It will be slow on larger data
As you get more experience with R, you might use data manipulation packages like dplyr or data.table for these types of manipulations.

#nelsonauner's answer does all the heavy lifting. But one thing to note, in my actual data my dates are not numerical like they are in the example above, they are dates listed as MM/DD/YYYY with the appropriate as.Date(nitrate$date, "%m/%d/%Y").
I found that the for loop above gave me all zeros for nitrate$prev_five_rainfall and I suspected it was a problem with the dates.
So I changed my dates in both data sets to numerical using the difference in number of days between a common start date and the recorded date, so that the for loop would look for a matching number of days in each data frame rather than a date. First, make a column of the start date using rep_len() and format it:
nitrate$startdate <- rep_len("01/01/1980", nrow(nitrate))
nitrate$startdate <- as.Date(all$startdate, "%m/%d/%Y")
Then, calculate the difference using difftime():
nitrate$diffdays <- as.numeric(difftime(nitrate$date, nitrate$startdate, units="days"))
Do the same for the rain data frame. Finally, the for loop looks like this:
nitrate$prev_five_rainfall = NA
for (i in 1:length(nitrate$diffdays)) {
day = nitrate$diffdays[i]
nitrate$prev_five_rainfall[i] = sum(rain$mm[(day-5):(day-1)]) # 5 days
}

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