ggdist psychometric functions

ggdist psychometric functions.R

library(tidyverse)
library(ggdist)

# make some data
expand_grid(
  condition = c("A", "B"),
  stimulus = seq(-3,3,0.3),
  repetitions = 1:20
) %>%
  # make some noisy response data
  mutate(response = round(pnorm(stimulus + rnorm(n()) + (condition == "A")*2-1))) %>%
  # evenly distribute the x positions over 5 sub-bins
  group_by(condition, response, stimulus) %>% 
  mutate(stimulus_spread = stimulus + (0:(n()-1) %% 5 - 2)/5*.3) %>% 
  ungroup() %>% 
  # plot it
  ggplot() +
  aes(x = stimulus_spread, y = response, color=condition, fill=condition) +
  ggdist::stat_dots(
    alpha = 0.5, # lower contrast
    binwidth = .3/5, # size of a sub-bin
    color = NA, # no outline
    orientation = "horizontal",
    aes(side=ifelse(condition=="A", "bottom", "top"))
  ) +
  geom_smooth(method = "glm", method.args = list(family = "binomial")) +
  scale_color_manual(values = c("#4DAF4A", "#984EA3")) +
  scale_fill_manual(values = c("#4DAF4A", "#984EA3")) +
  scale_y_continuous(breaks=c(0,0.5,1), labels=c("left", "", "right"), minor_breaks=FALSE) +
  labs(x="stimulus (right minus left)") +
  theme_minimal(16)

output.md