/* 

  Weather (Figaro) in Picat.

  Weather model from "Practical Probabilistic Programming" 
  page 21ff
  Figaro code at page 24
  """

  Figaro output:
  """
  Today's greeting is "Hello, world!" with probability 0.27999999999999997.
  If today's greeting is "Hello, world!", today's weather is sunny with probability 0.4285714285714285.
  If today's greeting is "Hello, world!", tomorrow's greeting will be "Hello, world!" with probability 0.24857142857142858.
  """


  Cf my Gamble model gamble_weather_figaro.rkt

  This program was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/

import ppl_distributions, ppl_utils.
import util.
% import ordset.

main => go.

/*

observe_greeting = false
var : sunny today
Probabilities:
false: 0.7780000000000000
true: 0.2220000000000000
mean = 0.222

var : greeting today
Probabilities:
Oh no, not again: 0.6166666666666667
Hello, world!: 0.2666666666666667
Howdy, universe!: 0.1166666666666667

var : sunny tomorrow
Probabilities:
false: 0.7856666666666666
true: 0.2143333333333333
mean = 0.214333

var : greeting tomorrow
Probabilities:
Oh no, not again: 0.7123333333333334
Hello, world!: 0.1746666666666667
Howdy, universe!: 0.1130000000000000


observe_greeting = Hello, world!
min_accepted_samples = 3000
var : sunny today
Probabilities:
false: 0.6100000000000000
true: 0.3900000000000000
mean = 0.39

var : greeting today
Probabilities:
Hello, world!: 1.0000000000000000
mean = [Hello, world! = 1.0]

var : sunny tomorrow
Probabilities:
false: 0.6596666666666666
true: 0.3403333333333333
mean = 0.340333

var : greeting tomorrow
Probabilities:
Oh no, not again: 0.5963333333333334
Hello, world!: 0.2343333333333333
Howdy, universe!: 0.1693333333333333


observe_greeting = Howdy, universe!
min_accepted_samples = 3000
var : sunny today
Probabilities:
true: 1.0000000000000000
mean = 1.0

var : greeting today
Probabilities:
Howdy, universe!: 1.0000000000000000
mean = [Howdy, universe! = 1.0]

var : sunny tomorrow
Probabilities:
true: 0.7923333333333333
false: 0.2076666666666667
mean = 0.792333

var : greeting tomorrow
Probabilities:
Hello, world!: 0.4193333333333333
Howdy, universe!: 0.3920000000000000
Oh no, not again: 0.1886666666666667


observe_greeting = Oh no, not again
min_accepted_samples = 3000
var : sunny today
Probabilities:
false: 1.0000000000000000
mean = 0.0

var : greeting today
Probabilities:
Oh no, not again: 1.0000000000000000
mean = [Oh no, not again = 1.0]

var : sunny tomorrow
Probabilities:
false: 0.9446666666666667
true: 0.0553333333333333
mean = 0.0553333

var : greeting tomorrow
Probabilities:
Oh no, not again: 0.8513333333333334
Hello, world!: 0.1193333333333333
Howdy, universe!: 0.0293333333333333



*/
go ?=>
  member(ObserveGreeting,[false,
                          "Hello, world!",
                          "Howdy, universe!",
                          "Oh no, not again"]),
  println(observe_greeting=ObserveGreeting),
  reset_store,
  Opts = [show_probs_trunc,mean],
  Options = cond(ObserveGreeting == false,
                 Opts,
                 Opts++[min_accepted_samples=3000,show_accepted_samples=false]),             
  run_model(3000,$model(ObserveGreeting),Options),
  
  nl,
  % show_store_lengths,nl,
  fail,
  nl.
go => true.
  
  
model(ObserveGreeting) =>
  SunnyToday = flip(2/10),
  GreetingToday = cond(SunnyToday == true,
                       categorical([5/10,5/10],["Hello, world!","Howdy, universe!"]),
                       categorical([2/10,8/10],["Hello, world!","Oh no, not again"])),

  SunnyTomorrow = cond(SunnyToday,flip(8/10),flip(5/100)),
  GreetingTomorrow = cond(SunnyTomorrow == true,
                          categorical([5/10,5/10],["Hello, world!","Howdy, universe!"]),
                          categorical([1/10,9/10],["Hello, world!","Oh no, not again"])),

  if ObserveGreeting != false then
    observe(GreetingToday == ObserveGreeting)
  end,
  
  if ObserveGreeting == false ; observed_ok then
    add("sunny today",SunnyToday),
    add("greeting today",GreetingToday),    
    add("sunny tomorrow",SunnyTomorrow),
    add("greeting tomorrow",GreetingTomorrow),    
  end.