/* 

  Inverse exponential dist in Picat.

  Note: Picat PPL currently supports only the random generation
        of inverse exponential dist.
        However, 
        inverse_exponential_dist(Lambda) is
        the same as exponential_dist(1/Lambda)

  (For parameter recovery, see ppl_exponential_dist.pi)

  Cf my Gamble model gamble_exponential_inverse_dist.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.

/*

  var : d1
  Probabilities (truncated):
  37.93462038516595: 0.0001000000000000
  37.238446746717976: 0.0001000000000000
  33.728340106723607: 0.0001000000000000
  33.412497657026073: 0.0001000000000000
  .........
  0.000781539805084: 0.0001000000000000
  0.000172575933265: 0.0001000000000000
  0.000164370635792: 0.0001000000000000
  0.000010006142261: 0.0001000000000000
  mean = 4.01317
  HPD intervals:
  HPD interval (0.94): 0.00016437063579..11.29407136026462

  var : d2
  Probabilities (truncated):
  43.22019350861278: 0.0001000000000000
  38.302692440626444: 0.0001000000000000
  34.421264018440937: 0.0001000000000000
  32.680865952194068: 0.0001000000000000
  .........
  0.001953294506768: 0.0001000000000000
  0.001690307096966: 0.0001000000000000
  0.000802045999014: 0.0001000000000000
  0.00056522421346: 0.0001000000000000
  mean = 4.02431
  HPD intervals:
  HPD interval (0.94): 0.00056522421346..11.27465191935672

*/
go ?=>
  reset_store,
  run_model(10_000,$model,[show_probs_trunc,mean,
                           % show_percentiles,show_histogram,
                           show_hpd_intervals,hpd_intervals=[0.94]
                           % min_accepted_samples=1000,show_accepted_samples=true
                          ]),
  nl,
  % show_store_lengths,nl,
  % fail,
  nl.
go => true.
  
  
model() =>
  Lambda = 4, % Is 1/4 in Gamble
  D1 = inverse_exponential_dist(Lambda),
  D2 = exponential_dist(1/Lambda),
  
  add("d1",D1),
  add("d2",D2).