westerman.R

# delta rule formula
# (i-o) o (1-o)

library(tidyverse)
d <- expand_grid(i =  seq(0.05,.95,.05),
            o = seq(0.05,.95,.05)) |>
  mutate(last_part = o * (1-o),
         first_part = abs(i-o),
         delta = abs((i-o) * o * (1-o)), 
         divergence = i * log(i/o)) 


d_wide <- d |>
  pivot_longer(last_part:divergence, names_to = "measure", values_to = "value") 

ggplot(d_wide, aes(x = i, y = value, col = o)) + 
  geom_line(aes(group = as.factor(o))) +
  facet_wrap(~measure, scales = "free_y") + 
  ylab("curiosity") + 
  xlab("input value") + 
  viridis::scale_color_viridis(name = "output value")