#
# Original code by Gaston Sanchez
#  https://www.r-bloggers.com/gauge-chart-in-r/
# Modified by Jeff Hemsley
#  Somelab.net
#  Twitter: @JeffHemsley
#
 
dial.plot <- function(label = "UseR!", value = 78, dial.radius = 1
          , value.cex = 3, value.color = "black"
          , label.cex = 3, label.color = "black"
          , gage.bg.color = "white"
          , yellowFrom = 75, yellowTo = 90, yellow.slice.color = "#FF9900"
          , redFrom = 90, redTo = 100, red.slice.color = "#DC3912"
          , needle.color = "red", needle.center.color = "black", needle.center.cex = 1
          , dial.digets.color = "grey50"
          , heavy.border.color = "gray85", thin.border.color = "gray20", minor.ticks.color = "gray55", major.ticks.color = "gray45") {
 
  whiteFrom = min(yellowFrom, redFrom) - 2
  whiteTo = max(yellowTo, redTo) + 2
 
  # function to create a circle
  circle <- function(center=c(0,0), radius=1, npoints=100)
  {
    r = radius
    tt = seq(0, 2*pi, length=npoints)
    xx = center[1] + r * cos(tt)
    yy = center[1] + r * sin(tt)
    return(data.frame(x = xx, y = yy))
  }
 
  # function to get slices
  slice2xy <- function(t, rad)
  {
    t2p = -1 * t * pi + 10*pi/8
    list(x = rad * cos(t2p), y = rad * sin(t2p))
  }
 
  # function to get major and minor tick marks
  ticks <- function(center=c(0,0), from=0, to=2*pi, radius=0.9, npoints=5)
  {
    r = radius
    tt = seq(from, to, length=npoints)
    xx = center[1] + r * cos(tt)
    yy = center[1] + r * sin(tt)
    return(data.frame(x = xx, y = yy))
  }
 
  # external circle (this will be used for the black border)
  border_cir = circle(c(0,0), radius=dial.radius, npoints = 100)
 
  # open plot
  plot(border_cir$x, border_cir$y, type="n", asp=1, axes=FALSE,
       xlim=c(-1.05,1.05), ylim=c(-1.05,1.05),
       xlab="", ylab="")
 
  # gray border circle
  external_cir = circle(c(0,0), radius=( dial.radius * 0.97 ), npoints = 100)
    # initial gage background
  polygon(external_cir$x, external_cir$y,
          border = gage.bg.color, col = gage.bg.color, lty = NULL)
 
  # add gray border
  lines(external_cir$x, external_cir$y, col=heavy.border.color, lwd=18)
  # add external border
  lines(border_cir$x, border_cir$y, col=thin.border.color, lwd=2)
 
  # yellow slice (this will be used for the yellow band)
  yel_ini = (yellowFrom/100) * (12/8)
  yel_fin = (yellowTo/100) * (12/8)
  Syel = slice2xy(seq.int(yel_ini, yel_fin, length.out = 30), rad= (dial.radius * 0.9) )
  polygon(c(Syel$x, 0), c(Syel$y, 0),
          border = yellow.slice.color, col = yellow.slice.color, lty = NULL)
 
  # red slice (this will be used for the red band)
  red_ini = (redFrom/100) * (12/8)
  red_fin = (redTo/100) * (12/8)
  Sred = slice2xy(seq.int(red_ini, red_fin, length.out = 30), rad= (dial.radius * 0.9) )
  polygon(c(Sred$x, 0), c(Sred$y, 0),
          border = red.slice.color, col = red.slice.color, lty = NULL)
 
  # white slice (this will be used to get the yellow and red bands)
  white_ini = (whiteFrom/100) * (12/8)
  white_fin = (whiteTo/100) * (12/8)
  Swhi = slice2xy(seq.int(white_ini, white_fin, length.out = 30), rad= (dial.radius * 0.8) )
  polygon(c(Swhi$x, 0), c(Swhi$y, 0),
          border = gage.bg.color, col = gage.bg.color, lty = NULL)
 
 
 
  # calc and plot minor ticks
  minor.tix.out <- ticks(c(0,0), from=5*pi/4, to=-pi/4, radius=( dial.radius * 0.89 ), 21)
  minor.tix.in <- ticks(c(0,0), from=5*pi/4, to=-pi/4, radius=( dial.radius * 0.85 ), 21)
  arrows(x0=minor.tix.out$x, y0=minor.tix.out$y, x1=minor.tix.in$x, y1=minor.tix.in$y,
         length=0, lwd=2.5, col=minor.ticks.color)
 
  # coordinates of major ticks (will be plotted as arrows)
  major_ticks_out = ticks(c(0,0), from=5*pi/4, to=-pi/4, radius=( dial.radius * 0.9 ), 5)
  major_ticks_in = ticks(c(0,0), from=5*pi/4, to=-pi/4, radius=( dial.radius * 0.77 ), 5)
  arrows(x0=major_ticks_out$x, y0=major_ticks_out$y, col=major.ticks.color,
         x1=major_ticks_in$x, y1=major_ticks_in$y, length=0, lwd=3)
 
  # calc and plot numbers at major ticks
  dial.numbers <- ticks(c(0,0), from=5*pi/4, to=-pi/4, radius=( dial.radius * 0.70 ), 5)
  dial.lables <- c("0", "25", "50", "75", "100")
  text(dial.numbers$x, dial.numbers$y, labels=dial.lables, col=dial.digets.color, cex=.8)
 
 
  # Add dial lables
  text(0, (dial.radius * -0.65), value, cex=value.cex, col=value.color)
  # add label of variable
  text(0, (dial.radius * 0.43), label, cex=label.cex, col=label.color)
 
  # add needle
  # angle of needle pointing to the specified value
  val = (value/100) * (12/8)
  v = -1 * val * pi + 10*pi/8 # 10/8 becuase we are drawing on only %80 of the cir
  # x-y coordinates of needle
  needle.length <- dial.radius * .67
  needle.end.x = needle.length * cos(v)
  needle.end.y = needle.length * sin(v)
 
  needle.short.length <- dial.radius * .1
  needle.short.end.x = needle.short.length * -cos(v)
  needle.short.end.y = needle.short.length * -sin(v)
 
  needle.side.length <- dial.radius * .05
  needle.side1.end.x = needle.side.length * cos(v - pi/2) 
  needle.side1.end.y = needle.side.length * sin(v - pi/2)
  needle.side2.end.x = needle.side.length * cos(v + pi/2) 
  needle.side2.end.y = needle.side.length * sin(v + pi/2)
 
  needle.x.points <- c(needle.end.x, needle.side1.end.x, needle.short.end.x, needle.side2.end.x)
  needle.y.points <- c(needle.end.y, needle.side1.end.y, needle.short.end.y, needle.side2.end.y)
  polygon(needle.x.points, needle.y.points, col=needle.color)
 
  # add central blue point
  points(0, 0, col=needle.center.color, pch=20, cex=needle.center.cex)
  # add values 0 and 100
}
 
 
par(mar=c(0.2,0.2,0.2,0.2), bg="black", mfrow=c(2,2))
 
dial.plot ()
dial.plot (label = "Working", value = 25, dial.radius = 1
      , value.cex = 3.3, value.color = "white"
      , label.cex = 2.7, label.color = "white"
      , gage.bg.color = "black"
      , yellowFrom = 73, yellowTo = 95, yellow.slice.color = "gold"
      , redFrom = 95, redTo = 100, red.slice.color = "red"
      , needle.color = "red", needle.center.color = "white", needle.center.cex = 1
      , dial.digets.color = "white"
      , heavy.border.color = "white", thin.border.color = "black", minor.ticks.color = "white", major.ticks.color = "white")
 
 
dial.plot (label = "caffeine", value = 63, dial.radius = .7
           , value.cex = 2.3, value.color = "white"
           , label.cex = 1.7, label.color = "white"
           , gage.bg.color = "black"
           , yellowFrom = 80, yellowTo = 93, yellow.slice.color = "gold"
           , redFrom = 93, redTo = 100, red.slice.color = "red"
           , needle.color = "red", needle.center.color = "white", needle.center.cex = 1
           , dial.digets.color = "white"
           , heavy.border.color = "black", thin.border.color = "lightsteelblue4", minor.ticks.color = "orange", major.ticks.color = "tan")
 
 
dial.plot (label = "Fun", value = 83, dial.radius = .7
           , value.cex = 2.3, value.color = "white"
           , label.cex = 1.7, label.color = "white"
           , gage.bg.color = "black"
           , yellowFrom = 20, yellowTo = 75, yellow.slice.color = "olivedrab"
           , redFrom = 75, redTo = 100, red.slice.color = "green"
           , needle.color = "red", needle.center.color = "white", needle.center.cex = 1
           , dial.digets.color = "white"
           , heavy.border.color = "black", thin.border.color = "lightsteelblue4", minor.ticks.color = "orange", major.ticks.color = "tan")