Create Percentage Change Labels Barplot - r

Question

I am trying to create a barchart which shows percentage change between the bars for each category of performance test (smallpt,compress etc)
Current Graph Example:
Data:
CG2400Host <- data.frame(
smallpt = c(38.934),
compress = c(58.036),
ffte = c(5629.20),
johntheripper = c(8067),
mtdgemm = c(2.043463),
stockfish = c(16746109),
streamCopy = c(83562.0),
streamScale = c(79536.7),
streamTriad = c(82708.4),
streamAdd = c(83041.6),
dbenchOneClient = c(579.090),
dbenchSixClient = c(2814.47),
dbenchTwelveClient = c(4141.33),
dbenchFortyEight = c(4044.82),
dbenchOneHundredTwentyEight = c(851.355),
dbenchTwoHundredFiftyEight = c(870.838)
)
CG2300Host <- data.frame(
smallpt = c(19.712),
compress = c(52.873),
ffte = c(4626.09),
johntheripper = c(8729),
mtdgemm = c(5.494281),
stockfish = c(17610837),
streamCopy = c(79427.8),
streamScale = c(60582.3),
streamTriad = c(69226.6),
streamAdd = c(67805.7),
dbenchOneClient = c(47.8331),
dbenchSixClient = c(67.661),
dbenchTwelveClient = c(82.4374),
dbenchFortyEight = c(109.27),
dbenchOneHundredTwentyEight = c(111.981),
dbenchTwoHundredFiftyEight = c(95.2279)
)
GB1UHost <- data.frame(
smallpt = c(17.530),
compress = c(44.628),
ffte = c(7365.97),
johntheripper = c(11684),
mtdgemm = c(1.161368),
stockfish = c(22878029),
streamCopy = c(44096.4),
streamScale = c(29866.3),
streamTriad = c(31804.6),
streamAdd = c(31796.5),
dbenchOneClient = c(755.644),
dbenchSixClient = c(3333.72),
dbenchTwelveClient = c(4497.29),
dbenchFortyEight = c(3510.50),
dbenchOneHundredTwentyEight = c(2092.10),
dbenchTwoHundredFiftyEight = c(1720.72)
)
DellHost <- data.frame(
smallpt = c(19.081),
compress = c(38.394),
ffte = c(8569.61),
johntheripper = c(13365),
mtdgemm = c(1.791839),
stockfish = c(22134688),
streamCopy = c(133314.5),
streamScale = c(89241.6),
streamTriad = c(94915.5),
streamAdd = c(93186.8),
dbenchOneClient = c(852.674),
dbenchSixClient = c(3369.59),
dbenchTwelveClient = c(4348.31),
dbenchFortyEight = c(1497.37),
dbenchOneHundredTwentyEight = c(1528.85),
dbenchTwoHundredFiftyEight = c(1505.47)
)
Current code:
createHostComparisonBarchart <- function(CG2300DF,CG2400DF,GB1UDF,DellDF){
BarChartNames<-c("Smallpt Barchart","Compressed G-Zip","FFTE","John The Ripper","Mt-dgemm","Stockfish","Stream - Copy",
"Stream - Scale","Stream - Triad","Stream - Add","Dbench 1 Client","Dbench 6 Client","Dbench 12 Client",
"Dbench 48 Client","Dbench 128 Client","Dbench 256 Client")
UnitNames <- c("seconds","seconds","MFLOPS/s","Crypts/s","MFLOPS/s","Nodes/s","MB/s","MB/s","MB/s","MB/s","MB/s","MB/s",
"MB/s","MB/s","MB/s","MB/s")
IndexNames <- c("smallpt","compress","ffte","johntheripper","mtdgemm","stockfish","streamCopy","streamScale","streamTriad",
"streamAdd","dbenchOneClient","dbenchSixClient","dbenchTwelveClient","dbenchFortyEight","dbenchOneHundredTwentyEight",
"dbenchTwoHundredFiftyEight")
for (i in 1:length(BarChartNames)){
values <- data.frame(
serverType <- c("CG2300","CG2400","GB1U","R6525 Dell"),
result <- c(CG2300DF[i],CG2400DF[i],GB1UDF[i],DellDF[i])
)
p<-ggplot(data=values, aes(x=serverType, y=result,fill=serverType)) +
geom_bar(stat="identity")+theme_minimal()+
xlab("Server Type")+
ylab(UnitNames[i])+
ggtitle(BarChartNames[i])
print(p)
}
}
I have a function for calculating the percentage change between the values:
percentageChangeCalc <-function(serverADF,serverBDF){
percentChange <-c()
for (i in 1:length(colnames(serverADF))){
val <- (serverBDF[i] - serverADF[i])/ serverADF[i]
percentChange <- append(percentChange,val)
}
percentChange
}
Since each "bar" in the chart is compared to the one next to it...
percentageChangeCalc(CG2300Host,CG2400Host)
percentageChangeCalc(CG400Host,GB1UHost)
percentageChangeCalc(GB1UHost,DellHost)
would work.
I have tried different iterations of implementing this from using geom_text to geom_label but I seem to keep getting Error: Discrete value supplied to continuous scale. This makes me think it is not possible to carry out this with my current data.
I am aiming for something like:
Any help appreciated.

Answer 1

Maybe this helps:
library(tidyverse)
set.seed(1337)
data <- tibble(year = seq(2014, 2019), value = rpois(6, lambda = 10))
data
#> # A tibble: 6 × 2
#> year value
#> <int> <int>
#> 1 2014 10
#> 2 2015 5
#> 3 2016 8
#> 4 2017 8
#> 5 2018 6
#> 6 2019 12
data %>%
mutate(
diff = dplyr::lead(value) - value,
label_y = value %>% map2_dbl(diff, ~ 1.1 * max(.x, .x + .y))
) %>%
ggplot(aes(year)) +
geom_col(aes(y = value)) +
geom_errorbar(aes(ymin = value, ymax = value + diff), color = "red", width = 0.3) +
geom_label(aes(y = label_y, label = diff), color = "red")
#> Warning: Removed 1 rows containing missing values (geom_label).
Created on 2022-02-22 by the reprex package (v2.0.0)