Visualizing keystrokes using ggplot2

keystrokes.R

##### Visualizing keystrokes using ggplot2 #####

library(ggplot2)

# a character string to visualize:
string <- 'R is an integrated suite of software facilities for data manipulation, calculation and graphical display.'

# a data.frame representing the keys of a qwerty keyboard
qwerty <- data.frame(
  id = 1:53,
  xmin = c(1:10, seq(0.5,0.5+10,1), seq(0.3,0.3+12,1), seq(-1.2, -1.2+12,1), -1.2, -1.2, -1.2, 11, 11.5, 11.8),
  xmax = c(2:11, seq(1.5,1.5+10,1), seq(1.3, 1.3+12,1), seq(-0.2, -0.2+12,1), 1, 0.5, 0.3, 13.3, 13.3, 13.3),
  ymin = c(rep(1,10), rep(2,11), rep(3,13), rep(4,13), 1, 2, 3, 1, 2, 4),
  ymax = c(rep(2,10), rep(3,11), rep(4,13), rep(5,13), 2, 3, 4, 2, 3, 5), 
  anno1 = c("Z", "X", "C", "V", "B", "N", "M", ",", ":", "?", "A", "S", "D", "F", "G", "H", "J", "K", "L", ":", '"', "Q", "W", "E", "R", "T", "Y", "U", "I", "O", "P", "{", "}", "|", "~", "1", "2", "3", "4", "5", "6", "7", "8", "9", "0", "-", "+", NA, NA, NA, NA, NA, NA),
  anno2 = c(NA,  NA,  NA,  NA,  NA,  NA,  NA,  "<", ">", "/", NA,  NA,  NA,  NA,  NA,  NA,  NA,  NA,  NA,  ";", "'", NA,  NA,  NA,  NA,  NA,  NA,  NA,  NA,  NA,  NA,  "[", "]", "\\", "`","!", "@", "#", "$", "%", "^", "&", "*", "(", ")", "_", "=", NA, NA, NA, NA, NA, NA)
)
# a data.frame to map the characters to the respective key (qwerty)
qwerty_map <- data.frame(id =   c(1,  2,  3,  4,  5,  6,  7,  8,  8,  9,  9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 20, 21, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 32, 33, 33,  34, 34, 35, 35, 36, 36, 37, 37, 38, 38, 39, 39, 40, 40, 41, 41, 42, 42, 43, 43, 44, 44, 45, 45, 46, 46, 47, 47, 48, 49, 50, 51, 52, 53),
                         sym = c('z','x','c','v','b','n','m',',','<','.','>','/','?','a','s','d','f','g','h','j','k','l',';',':',"'",'"','q','w','e','r','t','y','u','i','o','p','[','{',']','}','\\','|','`','~','1','!','2','@','3','#','4','$','5','%','6','^','7','&','8','*','9','(','0',')','-','_','=','+', 'def', 'def', 'def', 'def', 'def', 'def'))

# split the string in single characters and transform to lower case
chars <- tolower(unlist(strsplit(string, split=NULL)))

# get character frequencies
freq <- as.data.frame(table(chars))

# prepare the 'map'
map <- cbind(qwerty_map, Freq = 0)
map <- merge(map, freq, by.x="sym", by.y="chars", all=T) # capitals get lost here. Either include capitals in ``qwerty_map`` or transform ``chars`` to lower case only.
map$Freq <- ifelse(is.na(map$Freq.y), map$Freq.x, map$Freq.y)
map$Freq.x <- NULL
map$Freq.y <- NULL

# merge coordinates (``qwerty``) and actual data (``map``)
map <- merge(qwerty, map, by="id")

# plot
ggplot() + 
  geom_rect(aes(xmin=map[map$sym != 'def',]$xmin, xmax=map[map$sym != 'def',]$xmax,ymin=map[map$sym != 'def',]$ymin,ymax=map[map$sym != 'def',]$ymax, fill=map[map$sym != 'def',]$Freq), colour="black", size=2) + 
  geom_rect(aes(xmin=map[map$sym == 'def',]$xmin, xmax=map[map$sym == 'def',]$xmax,ymin=map[map$sym == 'def',]$ymin,ymax=map[map$sym == 'def',]$ymax), colour="black", size=2, fill="grey") +
  scale_fill_gradient(low="white", high="red") + 
  annotate("text", x = map[map$sym != 'def',]$xmin + 0.3, y = map[map$sym != 'def',]$ymax - 0.3, label = map[map$sym != 'def',]$anno1, size=5) + 
  annotate("text", x = map[map$sym != 'def',]$xmax - 0.3, y = map[map$sym != 'def',]$ymin + 0.3, label = map[map$sym != 'def',]$anno2, size = 4) +
  coord_fixed() +
  theme_void()