## Is there a way to get the order of dates within one row? (R)

Lets say I have a dataframe with two rows and three columns:

A <- c('2019-04-08', '2019-04-01') B <- c('2019-03-21', '2019-03-08') C <- c('2019-03-25', '2019-04-28') df <- data.frame(A, B ,C) df A B C 1 2019-04-08 2019-03-21 2019-03-25 2 2019-04-01 2019-03-08 2019-04-28

Is there a way to add the colnames by order of dates in the first row to a vector?

In this case:

first.row.order <- c('B', 'C', 'A')

If you want the order of column names for each row, then here it is:

v <- t(apply(df,1,function(x) names(df)[order(as.Date(x))]))

gives

> v [,1] [,2] [,3] [1,] "B" "C" "A" [2,] "B" "A" "C"

**Sorting with dates - tidyverse,** How can a table be created with sorted data(sorted data includes dates) I it works up to arrange and other useful functions for data wrangling. might find useful: Data Wrangling with R and the Tidyverse - 4 videos Otherwise, you need to make sure your dates are in something like yyyy-mm-dd order� R makes it easy to sort vectors in either ascending or descending order. Because each column of a data frame is a vector, you may find that you perform this operation quite frequently. How to sort a vector in ascending order

I think this might do the trick:

names(df) <- names(sort(df[1,]))

**How to order by date in R? - tools,** Hi everyone, I am new to data science and would be needing your help on an issue. I was working on Bike Sharing problem and wanted to sort my rows on the basis of date. Please correct me if I have used something wrong. hi there,. Well this is how I want you to proceed with this. Extract year,month and date from the� } } I am completely new to R so R vocabulary is limited at the moment. I'm not sure if i'm on the right tracted here. For example I not sure if I need dataframe of uniqueIDs (df1). Is there a way in a For loop that you can pinpoint all date instances for a given ID and then select the latest and add to new dataframe?

We can use

names(df)[order(as.Date(unlist(df[1, ])))] #[1] "B" "C" "A"

If you want to use to reorder dataframe

df[order(as.Date(unlist(df[1, ])))] # B C A #1 2019-03-21 2019-03-25 2019-04-08 #2 2019-03-08 2019-04-28 2019-04-01

**Dates and Times in R Without Losing Your Sanity,** Dates. The easiest way to make a date in R is to use as.Date(x) where x is the best approach is to store them in a dataframe with a DateTime column and a While those dates are correct in reference to UTC time, the 1st row for In order to avoid common traps, use UTC and the lubridate package often. You can add or subtract numbers from dates to create new dates. For example, to calculate the date that is seven days in the future, use the following: > xd + 7 [1] "2012-08-03" In the same way as with numbers or text, you can put multiple dates into a vector. To create a vector of seven days starting on July 27, add 0:6 to the

We can use `setcolorder`

from `data.table`

library(data.table) i1 <- setDT(df)[1, order(as.IDate(unlist(.SD)))] setcolorder(df, i1) df # B C A #1: 2019-03-21 2019-03-25 2019-04-08 #2: 2019-03-08 2019-04-28 2019-04-01

**16 Dates and times,** There are three types of date/time data that refer to an instant in time: A date. They automatically work out the format once you specify the order of the component. 4 2013 1 1 5 45 #> 5 2013 1 1 6 0 #> 6 2013 1 1 5 58 #> # … with 336,770 more rows Now that you know how to get date-time data into R's date- time data� Sort a data frame rows in ascending order (from low to high) using the R function arrange() [dplyr package] Sort rows in descending order (from high to low) using arrange () in combination with the function desc () [ dplyr package]

**Reorder Data Frame Rows in R,** Arrange rows The dplyr function arrange() can be used to reorder (or sort) rows by one or more variables. Instead of using the function desc(), you can prepend the sorting variable by a minus sign to indicate descending order, as follow. If the data contain missing values, they will always come at the end. The DATEDIFF () function will find the number of specified dateparts, in this case days, between two dates. The starting date is LOOKUP (MIN ([Order Date]),-1), which will return the date one row previous. Table functions can be computed differently to allow the calculation to be further customized.

**Time Series 02: Dealing With Dates & Times in R,** This tutorial explores working with date and time field in R. We will overview learned how to quickly plot these data by converting the date column to an R Date class. Let's have a look at one of our date-time strings to determine it's format. When plotting time series data, you might want to bin the values so that each data point corresponds to the sum for a given month or week. This post will show an easy way to use cut and ggplot2's stat_summary to plot month totals in R wi

**How to Sort a Data Frame by Multiple Columns in R,** Sort a data frame by multiple columns in R with the order function by vector type out in terms of syntax, the one that is most readily available to all installations of R dataframe object, and passing in the new index order that we' d like to have. We’ll use the row_number() function partitioned by date in an inner query, and then filter to row_num = 1 in the outer query to get just the first record per group. This function numbers each of the rows: row_number() over (partition by dt order by ct desc) row_num. We’ll plug it into an inner query, like so, to get the desired results: