Calculating the change in % of data by year-CodePudding

I am trying to calculate the % change by year in the following dataset, does anyone know if this is possible?

I have the difference but am unsure how we can change this into a percentage

C diff(economy_df_by_year$gdp_per_capita)

df
 year            gdp
 1998           8142.
 1999           8248.
 2000           8211.
 2001           7926.
 2002           8366.
 2003          10122.
 2004          11493.
 2005          12443.
 2006          13275.
 2007          15284.

CodePudding user response：

Assuming that gdp is the total value, you could do something like this:

library(tidyverse)
tribble(
  ~year,            ~gdp,
  1998,          8142,
  1999,          8248,
  2000,          8211,
  2001,          7926,
  2002,          8366,
  2003,         10122,
  2004,         11493,
  2005,         12443,
  2006,         13275,
  2007,         15284
) -> df
df |> 
  mutate(pdiff = 100*(gdp - lag(gdp))/gdp)
#> # A tibble: 10 × 3
#>     year   gdp  pdiff
#>    <dbl> <dbl>  <dbl>
#>  1  1998  8142 NA    
#>  2  1999  8248  1.29 
#>  3  2000  8211 -0.451
#>  4  2001  7926 -3.60 
#>  5  2002  8366  5.26 
#>  6  2003 10122 17.3  
#>  7  2004 11493 11.9  
#>  8  2005 12443  7.63 
#>  9  2006 13275  6.27 
#> 10  2007 15284 13.1

Which relies on the tidyverse framework.

If gdp is the difference, you will need the total to get a percentage, if that is what you mean by change in percentage by year.

CodePudding user response：

df$change <- NA
df$change[2:10] <- (df[2:10, "gdp"] - df[1:9, "gdp"]) / df[1:9, "gdp"]

This assigns the yearly GDP growth to each row except the first one where it remains as NA

CodePudding user response：

df$diff <- c(0,diff(df$gdp))
df$percentDiff <- 100*(c(0,(diff(df$gdp)))/(df$gdp - df$diff))

This is another possibility.