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How to rename a column in R

I need to rename the column labelled "Amount" with "Kurtosis" in a dataframe in R and cannot find the correct way to do this. I have tried the following.

library(tidyverse)
library(ggplot2)
library(scales)
library(readr)
library(moments) #needed to calculate skewness and kurtosis

xmas_df <- read.csv("C:/Excel/For R/tblMainXMasFund.csv", header = TRUE, stringsAsFactor = FALSE)
xmasTotals_df_Kurtosis <- xmas_df %>%
dplyr::rename(Kurtosis=Amount) %>%
group_by(Year, YTD_Range) %>%
summarise(Amount = kurtosis(Amount))

The above produces the following error:

Error in `summarise()`:
! Problem while computing `Amount = kurtosis(Amount)`.
i The error occurred in group 1: Year = 2018, YTD_Range =
"1/1/2018 to 12/31/2018".
Caused by error in `kurtosis()`:
! object 'Amount' not found

If I change dplyr::rename(Kurtosis=Amount) %>% to dplyr::rename(Amount=Kurtosis) %>% I get: ! Can't rename columns that don't exist.
x Column `Kurtosis` doesn't exist.

Any suggestions on how to modify the above would be appreciated.

Molly Fagan

You're not using the correct "piping" for the rename and it needs to be done separately from the summarise.

xmasTotals_df_Kurtosis %<>% rename(Amount = Kurtosis)

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Do that and the Amount column will exist and you'll be able to use it.

Bryan Schmidt

ASKER

I made the change you describe but get: Error in xmas_df %>% group_by(Year, YTD_Range) %>% summarise(Amount = kurtosis(Amount)) %>% :
could not find function "%<>%"

Here is my code:
xmas_df <- read.csv("C:/Excel/For R/tblMainXMasFund.csv", header = TRUE, stringsAsFactor = FALSE)
xmasTotals_df_Kurtosis <- xmas_df %>%
group_by(Year, YTD_Range) %>%
summarise(Amount = kurtosis(Amount)) %>%
xmasTotals_df_Kurtosis %<>% rename (Amount = Kurtosis)

What modifications should I make? Do I need to add a library that reads the function %<>%?

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Molly Fagan

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Bryan Schmidt

ASKER

I added the magrittr library but got the following message: Error in `stop_subscript()`:
! Can't rename columns that don't exist.
x Column `Kurtosis` doesn't exist.

I then reversed the order of Amount and Kurtosis in the last line to read xmasTotals_df_Kurtosis %<>% rename (Kurtosis = Amount) and it worked!

Thank you Molly! Your time and advice are greatly appreciated!