Draw a graph to emphasize the difference current and expected values in R

Question

I have a dataset for expected and current income:

 id currentsalary expectedsalary
1   1            NA           1500
2   2            NA           3000
3   3            NA             NA
4   4            NA             NA
5   5            NA           1500
6   6          1500           3000
7   7            NA           1500
8   8            NA           5000
9   9          1000           1500
10 10          3000           5000

I would like to show the distribution of the expected net income in relation to the current net income (charts + conclusions). I draw histograms:

hist(df$expectedsalary, col="pink", xlab="salary")
hist(df$currentsalary, col="blue", add=T)

But it doesn't show the relation correctly. I would like to put id's to x coordinate and current and expected salary on y-axis (one maybe a line over histogram) to emphasize the differences between expected and current salaries person-based. How should I do that?

Answer 1

I'd use a dotchart to plot the differences:

ILLUSTRATIVE DATA:

set.seed(122)
df <- data.frame(
  id = 1:10,
  exp = sample(1000:5000, 10),
  curr = sample(800: 4500, 10)
)

SOLUTION:

Calculate the difference:

df$diff <- df$curr - df$exp

Draw dotchart:

dotchart(df$diff, labels = df$id, main = "Difference in current v expected income",
         col = ifelse(df$diff < 0, "red", "blue"), density = 50, angle = 90)
abline(v = 0)

RESULT:

(obviously, this can be greatly embellished)

EDIT:

How about using a barplot?

barplot(df$diff, names = df$id, xlab = "ID", ylab = "Difference", 
        main = "Difference in current v expected income",
        col = ifelse(df$diff < 0, "red", "blue"), density = 50, angle = 90)
legend("topright", c("Current > Expected income", "Current < Expected income"), 
       fill = c("blue", "red"),
       cex = 0.8)

Result: