OMbook_glossary

Code used for entries in the glossary for the OMbook

I have put this here just to create a link to a developing Rmarkdown file of code I have used for entries in the glossary for the “OMbook”: Outcome measures and evaluation in counselling and psychotherapy.

• Information about the book is at https://ombook.psyctc.org/SAGE/
• Supplementary information is at https://ombook.psyctc.org/book/ and …
• … the glossary itself is at https://ombook.psyctc.org/glossary/

I’m not claiming the code is good, some of it certainly isn’t, but it works. Some of it uses real data which for now I am not making available until I am sure that is safe and OK with others involved in collecting the data. OK, the code itself is here.

This next bit is just to get a nice plot for the Rblog index.

Show code

library(tidyverse)
throwDice <- function(nThrows, nSides = 6, scoreSides = 1:6){
  ### function to simulate throwing dice (or anything really)
  ### defaults to six sided die with scores 1:6 but you can override that
  if(nThrows <= 0) {
    stop("nThrows must be positive")
  }
  if(nThrows > 8) {
    stop("nThrows must be under 9 (to keep things easy!)")
  }
  if(nThrows - round(nThrows) > .Machine$double.eps) {
    warning("nThrows wasn't integer, rounded to integer")
    nThrows <- round(nThrows)
  }
  newScores <- scoreSides
  while(nThrows > 1) {
    newScores <- as.vector(outer(newScores, scoreSides, FUN = "+"))
    nThrows <- nThrows - 1
  }
  newScores
}
# throwDice(0)
# throwDice(1)
# throwDice(1.1)
# throwDice(11)
# throwDice(2)
# length(throwDice(2))
# min(throwDice(2))
# max(throwDice(2))
# nThrows <- 3
# throwDice(nThrows)
# length(throwDice(nThrows))
# min(throwDice(nThrows))
# max(throwDice(nThrows))
# nThrows <- 4
# throwDice(nThrows)
# length(throwDice(nThrows))
# min(throwDice(nThrows))
# max(throwDice(nThrows))


1:8 %>%
  as_tibble() %>%
  rename(nThrows = value) %>%
  rowwise() %>%
  mutate(score = list(throwDice(nThrows)),
         nThrowsFac = factor(nThrows)) %>%
  ungroup() %>%
  unnest_longer(score) %>%
  group_by(nThrowsFac) %>%
  mutate(nScores = n()) %>%
  ungroup() %>%
  group_by(nThrowsFac, score) %>%
  summarise(nThrows = first(nThrows),
            nScores = first(nScores),
            n = n(),
            p = n / nScores) %>%
  ungroup() -> tibDiceThrows

ggplot(data = tibDiceThrows,
       aes(x = score, y = p, colour = nThrowsFac)) +
  geom_point()  +
  geom_line() +
  ylab("Probability") +
  scale_x_continuous(name = paste0("Total score from n dice (with n from 1 to ",
                                   max(tibDiceThrows$nThrows),
                                   ")"),
                     breaks = seq(2, max(tibDiceThrows$score), 2)) +
  scale_colour_discrete(name = "n(throws)") +
  theme(axis.text.x = element_text(angle = 70, hjust = 1))