gt_brgraph: Plot best reactions for two person normal form games
In macartan/hop: Generates plots for various games used in Political Games

This function plots best reactions. Intersections are Nash equilibria. Thanks to Neelan Sircar for developing much of this code. To show utilities for players use util = TRUE. To show best response functions use BR = TRUE. Both can be done also with output either aligned horizontally or vertically, using vert.

gt_brgraph(X, Y = t(X), players = c("Row", "Col"), PR = players[1],
  P1 = PR, PC = players[2], P2 = PC, labelsR = c("C", "D"),
  labels1 = labelsR, labelsC = labels1, labels2 = labelsC, legBR = TRUE,
  legr = TRUE, legc = TRUE, leglocBR = c(0.8, 0.2), legxyr = c(c(0.8, 3
  * (min(C) + max(C))/4)), legxyc = c(c(0.8, (min(C) + max(C))/4)),
  ulegend = TRUE, BR = TRUE, br = BR, draw1 = TRUE, draw2 = TRUE,
  vert = TRUE, util = FALSE, overrow = TRUE, Rloc = NULL, Cloc = NULL,
  ur = TRUE, u1 = ur, uc = TRUE, u2 = uc, cthighlight = FALSE,
  rthighlight = FALSE, cbhighlight = FALSE, rbhighlight = FALSE,
  colr = "red", colc = gray(0.4), col1 = colr, col2 = colc,
  mmcol_r = "pink", mmcol_c = grey(0.8), mmcol_1 = mmcol_r,
  mmcol_2 = mmcol_c, xlabu = paste("Probability on", labelsR[1], "for", PR),
  ylabu = NULL, legtextr = c(paste(PR, "'s utility | ", PC, " plays ",
  labelsC[1], ")", sep = ""), paste(PR, "'s utility | ", PC, " plays ",
  labelsC[2], ")", sep = "")), legtextc = c(paste(PC, "'s utility | ", PC,
  " plays ", labelsC[1], ")", sep = ""), paste(PC, "'s utility | ", PC,
  " plays ", labelsC[2], ")", sep = "")), mainbr = "", mainu = "",
  hl_lwd = 8, lwd = 2)

`PR`	Name of row player
`P1`	alternative argument for Row Name
`PC`	Name of column player
`P2`	alternative argument for Col Name
`overrow`	Switch to have utilty plots plotted over row player (player 1)
`R`	Row payoffs
`C`	Column payoffs

C <- matrix(c(1,0,0,1),2,2)
R <- matrix(c(1,0,0,1),2,2)
gt_brgraph(R, C, PR="Country R", PC="Country C", leglocBR=c(.8,.2))
# A chicken game:

gt_brgraph(Chicken, BR = FALSE, util = TRUE,
  cthighlight = TRUE, rthighlight = TRUE,
  labelsC = c("Jill A", "Jill B"),
  labelsC = c("Jack A", "Jack B"),
  ur = TRUE,
  PC = "Jill", PR = "Jack")