noecho

# speed of light data set

# assume observations are iid t(10, mu, sigma)
# prior for (mu, sigma) proportional to 1/sigma
# column 'x' is mu, 'y' is log sigma, 
# output column 'f' gives values of log posterior
# NOTE:  columns 'data', 'x', 'y', 'f' should be already defined

name c91 'df' c92 's2'
let 'df'=10
set 'data'
28 26 33 24 34 -44 27 16 40 -2
29 22 24 21 25 30 23 29 31 19
24 20 36 32 36 28 25 21 28 29
37 25 28 26 30 32 36 26 30 22
36 23 27 27 28 27 31 27 26 33
26 32 32 24 39 28 24 25 32 25
29 27 28 29 16 23
let k92=count('data')
let 's2'=exp(2*'y')

let 'f'=0*'x'
store 'temp';
 replace.
  let k91=k91+1
  let 'f'='f'+log(1+('data'(k91)-'x')**2/'s2'/'df')
end
let k91=0
exec  'temp' k92

let 'f'=-k92*'y'-('df'+1)/2*'f'