Bug fixes for when die roll is non-integer

Also added a reroll function and simplified code greatly

DESCRIPTION

@@ -10,5 +10,6 @@ License: What license is it under?
 Encoding: UTF-8
 LazyData: true
 Imports:
-    ggplot2 (>= 3.1.0)
+    ggplot2 (>= 3.1.0),
+    dplyr (>= 0.8.1)
 RoxygenNote: 6.1.1

NAMESPACE

@@ -12,6 +12,7 @@ S3method(plot,Die)
 S3method(print,Die)
 S3method(summary,Die)
 export(advantage)
+export(combineDice)
 export(d10)
 export(d12)
 export(d20)
@@ -20,5 +21,7 @@ export(d6)
 export(d8)
 export(disadvantage)
 export(makeDie)
+export(reroll)
 export(roll)
+import(dplyr)
 import(ggplot2)

R/combineDice.R

@@ -0,0 +1,37 @@
+
+
+#' Combine Dice
+#'
+#' This function is a way to combine two independent dice rolls into a new die.
+#'
+#' @param x A die
+#' @param y A die
+#' @param fun A function that takes two vectors containing the possible
+#'   combinations of die rolls of \code{x} and \code{y}; the output should be of
+#'   the same length. Example - \code{pmax} is such a function and is used to
+#'   take the maximum of two rolls.
+#'
+#' @return A new die with the possible possibilities and their corresponding
+#'   probabilties
+#' @export
+#'
+#' @examples
+#' summed.die <- combineDice(d4, d6, `+`)
+#' advantaged.die <- combineDice(d4, d4, pmax)
+combineDice <- function(x, y, fun){
+  rolls <- expand.grid(x.numbers = x$numbers, y.numbers = y$numbers)
+  rolls$x.probs <- getProbabilitiy(x, rolls$x.numbers)
+  rolls$y.probs <- getProbabilitiy(y, rolls$y.numbers)
+  rolls$combined.prob <- rolls$x.probs*rolls$y.probs
+  rolls$combined.num <- fun(rolls$x.numbers, rolls$y.numbers)
+
+  new.die.probs <- rolls %>%
+    group_by(combined.num) %>%
+    summarize(prob = sum(combined.prob)) %>%
+    arrange(combined.num)
+
+  new.die <- makeDie(new.die.probs$combined.num, new.die.probs$prob)
+
+  return(new.die)
+
+}

R/disadvantage_advantage.R

@@ -17,37 +17,7 @@ disadvantage <- function(x, y=NULL){
     y = x
   }
 
-  minX = min(x$numbers)
-  minY = min(y$numbers)
-
-  maxX = max(x$numbers)
-  maxY = max(y$numbers)
-
-  range_z_min = pmin(minX, minY)
-  range_z_max = pmin(maxX, maxY)
-
-  z_numbers = c()
-  probabilities = c()
-  for(num in range_z_min:range_z_max){
-    prob_x_eq_num = getProbabilitiy(x, num)
-    prob_y_eq_num = getProbabilitiy(y, num)
-
-    y_geq_nums = y$numbers[y$numbers >= num] # >= not a mistake
-    x_ge_nums = x$numbers[x$numbers > num]
-
-    prob_y_geq_nums = sum(getProbabilitiy(y, y_geq_nums))
-    prob_x_ge_nums = sum(getProbabilitiy(x, x_ge_nums))
-
-    prob_num = prob_x_eq_num*prob_y_geq_nums + prob_x_ge_nums*prob_y_eq_num
-    if(prob_num > 0){
-      z_numbers = c(z_numbers, num)
-      probabilities = c(probabilities, prob_num)
-    }
-  }
-
-  z = makeDie(z_numbers, probabilities)
-  return(z)
-
+  return(combineDice(x, y, pmin))
 }
 
 #'
@@ -68,35 +38,7 @@ advantage <- function(x, y=NULL){
     y = x
   }
 
-  minX = min(x$numbers)
-  minY = min(y$numbers)
-
-  maxX = max(x$numbers)
-  maxY = max(y$numbers)
-
-  range_z_min = pmax(minX, minY)
-  range_z_max = pmax(maxX, maxY)
-
-  z_numbers = c()
-  probabilities = c()
-  for(num in range_z_min:range_z_max){
-    prob_x_eq_num = getProbabilitiy(x, num)
-    prob_y_eq_num = getProbabilitiy(y, num)
-
-    y_leq_nums = y$numbers[y$numbers <= num] # <= not a mistake
-    x_le_nums = x$numbers[x$numbers < num]
-
-    prob_y_leq_nums = sum(getProbabilitiy(y, y_leq_nums))
-    prob_x_le_nums = sum(getProbabilitiy(x, x_le_nums))
-
-    prob_num = prob_x_eq_num*prob_y_leq_nums + prob_x_le_nums*prob_y_eq_num
-    if(prob_num > 0){
-      z_numbers = c(z_numbers, num)
-      probabilities = c(probabilities, prob_num)
-    }
-  }
-
-  z = makeDie(z_numbers, probabilities)
-  return(z)
+  return(combineDice(x, y, pmax))
 
 }
+

R/internal_functions.R

@@ -8,36 +8,10 @@ getProbabilitiy <- function(x, numbers){
 }
 
 
-sumTwoDie <- function(x, y){
-  range_z_min = min(x$numbers) + min(y$numbers)
-  range_z_max = max(x$numbers) + max(y$numbers)
-
-  z_numbers = c()
-  probabilities = c()
-  for(num in range_z_min:range_z_max){
-    prob_num = sum(x$probs * getProbabilitiy(y, num - x$numbers))
-    if(prob_num > 0){
-      z_numbers = c(z_numbers, num)
-      probabilities = c(probabilities, prob_num)
-    }
-  }
-
-  z = makeDie(z_numbers, probabilities)
-  return(z)
-}
-
 # comparerFun(x, y); which both x & y as Die, or one of them as numeric
 compareDie <- function(x, y, comparerFun){
   if(class(x) == "Die" & class(y) == "Die"){
-    jointProbs = expand.grid(x$probs, y$probs)
-    jointProbs = jointProbs[,1]*jointProbs[,2]
-
-    jointNumbers = expand.grid(x$numbers, y$numbers)
-    matchResults = comparerFun(jointNumbers[,1], jointNumbers[,2])
-    probTrue = sum(jointProbs[matchResults])
-
-    z = makeDie(c(F,T), probs=c(1-probTrue, probTrue))
-    return(z)
+    return(combineDice(x, y, comparerFun))
   }
 
   if(class(x) %in% c("numeric", "integer")){
@@ -67,3 +41,4 @@ compareDie <- function(x, y, comparerFun){
 
   z = makeDie(c(F,T), probs=c(1-probTrue, probTrue))
 }
+

R/operators.R

@@ -2,7 +2,7 @@
 #' @export
 '+.Die' <- function(x, y){
   if(class(x) == "Die" & class(y) == "Die"){
-    return(sumTwoDie(x, y))
+    return(combineDice(x, y, `+`))
   }
 
   if(class(x) %in% c("numeric", "integer")){

R/reroll.R

@@ -0,0 +1,20 @@
+
+#' Reroll
+#'
+#' If the die lands on the provided \code{numbers}, then the die is re-rolled
+#' once with the output being final.
+#'
+#' @param x The die to possibly reroll
+#' @param numbers The numbers to reroll on
+#'
+#' @return A new die with updated probabilties
+#' @export
+#'
+#' @examples
+#' paladin.greataxe <- reroll(d12, 1:2)
+reroll <- function(x, numbers){
+  which.die.fun <- function(a, b){
+    ifelse(a %in% numbers, b, a)
+  }
+  return(combineDice(x, x, which.die.fun))
+}

R/zzz.R

@@ -1,2 +1,3 @@
 #' @import ggplot2
+#' @import dplyr
 NULL

man/combineDice.Rd

@@ -0,0 +1,29 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/combineDice.R
+\name{combineDice}
+\alias{combineDice}
+\title{Combine Dice}
+\usage{
+combineDice(x, y, fun)
+}
+\arguments{
+\item{x}{A die}
+
+\item{y}{A die}
+
+\item{fun}{A function that takes two vectors containing the possible
+combinations of die rolls of \code{x} and \code{y}; the output should be of
+the same length. Example - \code{pmax} is such a function and is used to
+take the maximum of two rolls.}
+}
+\value{
+A new die with the possible possibilities and their corresponding
+  probabilties
+}
+\description{
+This function is a way to combine two independent dice rolls into a new die.
+}
+\examples{
+summed.die <- combineDice(d4, d6, `+`)
+advantaged.die <- combineDice(d4, d4, pmax)
+}

man/reroll.Rd

@@ -0,0 +1,23 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/reroll.R
+\name{reroll}
+\alias{reroll}
+\title{Reroll}
+\usage{
+reroll(x, numbers)
+}
+\arguments{
+\item{x}{The die to possibly reroll}
+
+\item{numbers}{The numbers to reroll on}
+}
+\value{
+A new die with updated probabilties
+}
+\description{
+If the die lands on the provided \code{numbers}, then the die is re-rolled
+once with the output being final.
+}
+\examples{
+paladin.greataxe <- reroll(d12, 1:2)
+}