R 根据一年计算减少百分比
我有这个数据框:R 根据一年计算减少百分比,r,dplyr,percentage,R,Dplyr,Percentage,我有这个数据框: dat = read.delim(text = "LM, year 85.20000, 2020 56.70000, 2021 49.00000, 2022 71.00000, 2023 33.00000, 2024 96.50000, 2025 26.30000, 2026 21.30000, 2027", sep = ",", header = T) 我想计算特定年份的减少百分比变化,我写了这个函数:
dat = read.delim(text = "LM, year
85.20000, 2020
56.70000, 2021
49.00000, 2022
71.00000, 2023
33.00000, 2024
96.50000, 2025
26.30000, 2026
21.30000, 2027", sep = ",", header = T)
我想计算特定年份的减少百分比变化,我写了这个函数:
pChange = function( dat , startYear){
lastYear = max(dat$year)
res = dat %>% arrange(year) %>%
mutate(change = (LM[year == lastYear] - LM[year == startYear]) / LM[year == startYear])
res
}
pChange( dat, startYear = 2022)
然而,我每年都得到相同的值,我认为这是一个问题,但我不知道如何解决它。有什么想法吗
LM year change
1 85.2 2020 -0.5653061
2 56.7 2021 -0.5653061
3 49.0 2022 -0.5653061
4 71.0 2023 -0.5653061
5 33.0 2024 -0.5653061
6 96.5 2025 -0.5653061
7 26.3 2026 -0.5653061
8 21.3 2027 -0.5653061
如果你想计算从
startYear
到每年的百分比变化,我相信你不想包括lastYear
pChange = function(dat, startYear){
res = dat %>%
arrange(year) %>%
mutate(change = (LM - LM[year == startYear]) / LM[year == startYear])
res
}
pChange(dat, startYear = 2022)
LM year change
1 85.2 2020 0.7387755
2 56.7 2021 0.1571429
3 49.0 2022 0.0000000
4 71.0 2023 0.4489796
5 33.0 2024 -0.3265306
6 96.5 2025 0.9693878
7 26.3 2026 -0.4632653
8 21.3 2027 -0.5653061
我建议您首先计算上一年的所有百分比变化,然后将您要查找的百分比子集:
library(tidyverse)
dat <- tribble(
~ LM, ~ year,
85.20000, 2020,
56.70000, 2021,
49.00000, 2022,
71.00000, 2023,
33.00000, 2024,
96.50000, 2025,
26.30000, 2026,
21.30000, 2027,
)
pchange <- function(dat, start_year) {
output <- dat %>%
mutate(change = (LM - lag(LM, order_by = year)) / LM) %>%
filter(year == start_year)
output$change
}
pchange(dat, 2025)
库(tidyverse)
datlag
功能在这些情况下非常有用。