Ludo
Ludo

Reputation: 281

Waterfall plots with ggplot

I am trying to do some waterfall plots using the following code I found on the internet and adapted:

waterfall <- function(balance){
balance$desc <- factor(balance$desc, levels = balance$desc)
balance$id <- seq_along(balance$amount)
balance$type <- ifelse(balance$amount > 0, "increase","decrease")
balance[balance$id %in% c(1,dim(balance)[1]),"type"] <- "net"
balance$end <- cumsum(balance$amount)
balance$end <- c(head(balance$end, -1), 0)
balance$start <- c(0, head(balance$end, -1))
balance <- balance[, c(3, 1, 4, 6, 5, 2)]
balance
balance$type <- factor(balance$type, levels = c("decrease","increase", "net"))
p1 <- ggplot(balance, aes(desc, fill = type)) + 
geom_rect(aes(x = desc,xmin = id - 0.45, xmax = id + 0.45, ymin = end,ymax = start))+
xlab("") + 
ylab("") + 
geom_text(subset = .(type == "increase"), aes(id,end, label = comma(amount)), vjust = 1, size = 4,fontface="bold") +
geom_text(subset = .(type == "decrease"), aes(id,end, label = comma(amount)), vjust = -0.3,size = 4,fontface="bold")+
geom_text(data = subset(balance,type == "net" & id == min(id)), aes(id, end, label = comma(end), vjust = ifelse(end <start, 1, -0.3)), size = 4,fontface="bold") + 
geom_text(data = subset(balance,type == "net" & id == max(id)), aes(id, start, label = comma(start), vjust = ifelse(end < start, -0.3, 1)), size = 4,fontface="bold")+
theme_bw()+
theme(legend.position = "none")
return(p1)
}

I am quite happy with the result if I use it on the following example

balance <- data.frame(desc = c("Starting Cash","Sales", "Refunds", "Payouts", "Court Losses","Court Wins", "Contracts", "End Cash"), 
                  amount = c(2000, 3400, -1100, -100, -6600, 3800, 1400, 2800))

but if I want to plot a waterfall with only increases (resp. decreases) such as on the following example

balance <- data.frame(desc = c("Starting Cash", "Court Losses","Court Wins", "Contracts", "End Cash"), 
                  amount = c(2000, -1100, -100, -6600, 2800))

then I have an error

Error in if (nrow(layer_data) == 0) return() : argument is of length zero

I guess it has something to do with the subset argument in the geom_text, but I have no idea how to treat the case where the subset is empty.

I have a second question. I am happy with the three colors that I have in the first case. However, if I run the code on the second example, by removing the faulty portion of the code, I get a graph with only two colors that are different than on the previous case. Is it possible to fix the colors such as to have blue/red/green as in the first example ?

Thanks.

Upvotes: 1

Views: 1424

Answers (1)

wici
wici

Reputation: 1711

It is indeed because of the empty subset for "increase". An easy way to avoid such empty subsets is with if statements:

waterfall <- function(balance){
  balance$desc <- factor(balance$desc, levels = balance$desc)
  balance$id <- seq_along(balance$amount)
  balance$type <- ifelse(balance$amount > 0, "increase","decrease")
  balance[balance$id %in% c(1,dim(balance)[1]),"type"] <- "net"
  balance$end <- cumsum(balance$amount)
  balance$end <- c(head(balance$end, -1), 0)
  balance$start <- c(0, head(balance$end, -1))
  balance$type <- factor(balance$type, levels = c("decrease","increase", "net"))
  p1 <- ggplot(balance, aes(desc, fill = type)) + 
    geom_rect(aes(x = desc,xmin = id - 0.45, xmax = id + 0.45, ymin = end,ymax = start))+
    xlab("") + 
    ylab("") + 
    geom_text(data = subset(balance,type == "net" & id == min(id)), aes(id, end, label = comma(end), vjust = ifelse(end <start, 1, -0.3)), size = 4,fontface="bold") + 
    geom_text(data = subset(balance,type == "net" & id == max(id)), aes(id, start, label = comma(start), vjust = ifelse(end < start, -0.3, 1)), size = 4,fontface="bold")+
    theme_bw()+
    theme(legend.position = "none")
  if ("increase" %in% balance$type){
    p1 <- p1 + geom_text(subset = .(type == "increase"), aes(id,end, label = comma(amount)), vjust = 1, size = 4,fontface="bold")
  }
  if ("decrease" %in% balance$type){
    p1 <- p1 + geom_text(subset = .(type == "decrease"), aes(id,end, label = comma(amount)), vjust = -0.3,size = 4,fontface="bold")
  }
  p1
}

You can fix the colors for your different levels by adding

scale_fill_manual(values = c(decrease = "indianred",increase ="forestgreen", net = "dodgerblue2"))

to your ggplot.

Upvotes: 1

Related Questions