user_zsum_child_rate.py#

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Constrain Sum of Child Rate Effect to Zero#

See Also#

user_zsum_mulcov_rate.py , user_zsum_mulcov_meas.py

Purpose#

This example demonstrates using The zero_sum_child_rate to improve the speed and accuracy of estimation of the fixed effects.

Problem Parameters#

number_data       = 50
iota_parent       = 1e-2
rho_parent        = 2e-2
rate_effect_child = 0.2;
measurement_cv    = 0.01

Data Simulation#

north_america#

The true rates for the parent region north_america (used for simulating data) are the iota_parent and rho_parent problem parameters.

canada#

The true child rate effect for canada is rate_effect_child .

united_states#

The true child rate effect for the united_states is - rate_effect_child .

mexico#

No data is included for mexico, hence it is automatically constrained to have zero child rate random effects.

Nodes#

There are just four nodes for this example, The parent node, north_america , and the three child nodes united_states , canada and mexico .

Model Variables#

The non-zero model_variables for this example are iota and rho . Both the parent and child rates use a grid with one point in age and two points in time. Thus there are six model variables for each rate, two for the parent rates and four for the child rate effects. The resulting rates will be constant in age and constant in time except between the two time grid points where it is linear with respect to time.

Source Code#

# ------------------------------------------------------------------------
# begin problem parameters
number_data       = 50
iota_parent       = 1e-2
rho_parent        = 2e-2
rate_effect_child = 0.2;
measurement_cv    = 0.01
# end problem parameters
# ------------------------------------------------------------------------
import sys
import os
import copy
import math
import random
import time
test_program = 'example/user/zsum_child_rate.py'
if sys.argv[0] != test_program  or len(sys.argv) != 1 :
   usage  = 'python3 ' + test_program + '\n'
   usage += 'where python3 is the python 3 program on your system\n'
   usage += 'and working directory is the dismod_at distribution directory\n'
   sys.exit(usage)
print(test_program)
#
# import dismod_at
local_dir = os.getcwd() + '/python'
if( os.path.isdir( local_dir + '/dismod_at' ) ) :
   sys.path.insert(0, local_dir)
import dismod_at
#
# change into the build/example/user directory
if not os.path.exists('build/example/user') :
   os.makedirs('build/example/user')
os.chdir('build/example/user')
# ------------------------------------------------------------------------
python_seed = int( time.time() )
random.seed( python_seed )
# ------------------------------------------------------------------------
# Note that the a, t values are not used for this example
def example_db (file_name) :
   def fun_rate_child(a, t) :
      return ('prior_rate_child', None, 'prior_gauss_diff')
   def fun_rate_parent(a, t) :
      return ('prior_rate_parent', None, 'prior_gauss_diff')
   import dismod_at
   # ----------------------------------------------------------------------
   # age list
   age_list    = [ 0.0,   50.0,  100.0 ]
   #
   # time list
   time_list   = [ 1990.0, 2010.0 ]
   #
   # integrand table
   integrand_table = [
      { 'name':'Sincidence' },
      { 'name':'remission' }
   ]
   #
   # node table: north_america -> (united_states, canada)
   node_table = [
      { 'name':'north_america', 'parent':''              },
      { 'name':'united_states', 'parent':'north_america' },
      { 'name':'canada',        'parent':'north_america' },
      { 'name':'mexico',        'parent':'north_america'}
   ]
   #
   # weight table:
   weight_table = list()
   #
   # covariate table: no covriates
   covariate_table = list()
   #
   # mulcov table
   mulcov_table = list()
   #
   # avgint table: same order as list of integrands
   avgint_table = list()
   #
   # nslist_dict:
   nslist_dict = dict()
   # ----------------------------------------------------------------------
   # data table
   data_table = list()
   # write out data
   row = {
      'density':     'gaussian',
      'weight':      '',
      'hold_out':     False,
      'age_lower':    50.0,
      'age_upper':    50.0,
      'subgroup':     'world',
   }
   for data_id in range(number_data) :
      if data_id % 3 == 0 :
         row['node']       = 'north_america'
         row['data_name']  = 'na_' + str( data_id / 3 )
         effect_true       = 0.0
      if data_id % 3 == 1 :
         row['node']       = 'united_states'
         row['data_name']  = 'us_' + str( data_id / 3 )
         effect_true       = - rate_effect_child
      if data_id % 3 == 2 :
         row['node']       = 'canada'
         row['data_name']  = 'ca_' + str( data_id / 3 )
         effect_true       = + rate_effect_child
      if data_id % 2 == 0 :
         row['time_lower'] = 1990.0
         row['time_upper'] = 1990.0
      else :
         row['time_lower'] = 2010.0
         row['time_upper'] = 2010.0
      #
      if data_id < number_data / 2 :
         iota_true         = math.exp(effect_true) * iota_parent
         row['integrand']  = 'Sincidence'
         row['meas_std']   = iota_true * measurement_cv
         noise             = iota_true * random.gauss(0.0, measurement_cv)
         row['meas_value'] = iota_true + noise
      else :
         rho_true          = math.exp(effect_true) * rho_parent
         row['integrand']  = 'remission'
         row['meas_std']   = rho_true * measurement_cv
         noise             = rho_true * random.gauss(0.0, measurement_cv)
         row['meas_value'] = rho_true + noise
      #
      data_table.append( copy.copy(row) )
   #
   # ----------------------------------------------------------------------
   # prior_table
   prior_table = [
      { # prior_rate_parent
         'name':     'prior_rate_parent',
         'density':  'uniform',
         'lower':    min(iota_true, rho_true) / 100.0,
         'upper':    max(iota_true, rho_true) * 100.0,
         'mean':     (iota_true + rho_true),
      },{ # prior_rate_child
         'name':     'prior_rate_child',
         'density':  'gaussian',
         'mean':     0.0,
         'std':      100.0, # very large so like uniform distribution
      },{ # prior_gauss_diff
         'name':     'prior_gauss_diff',
         'density':  'gaussian',
         'mean':     0.0,
         'std':      100.0, # very large so like uniform distribution
      }
   ]
   # ----------------------------------------------------------------------
   # smooth table
   smooth_table = [
      { # smooth_rate_child
         'name':                     'smooth_rate_child',
         'age_id':                   [ 0 ],
         'time_id':                  [ 0, 1 ],
         'fun':                      fun_rate_child
      },{ # smooth_rate_parent
         'name':                     'smooth_rate_parent',
         'age_id':                   [ 0 ],
         'time_id':                  [ 0, 1 ],
         'fun':                       fun_rate_parent
      }
   ]
   # ----------------------------------------------------------------------
   # rate table
   rate_table = [
      {
         'name':          'iota',
         'parent_smooth': 'smooth_rate_parent',
         'child_smooth':  'smooth_rate_child',
      },{
         'name':          'rho',
         'parent_smooth': 'smooth_rate_parent',
         'child_smooth':  'smooth_rate_child',
      }
   ]
   # ----------------------------------------------------------------------
   # option_table
   option_table = [
      { 'name':'parent_node_name',       'value':'north_america'     },
      { 'name':'zero_sum_child_rate',    'value':'iota rho'          },
      { 'name':'random_seed',            'value':'0'                 },
      { 'name':'ode_step_size',          'value':'10.0'              },
      { 'name':'rate_case',              'value':'iota_pos_rho_pos'  },

      { 'name':'quasi_fixed',            'value':'true'          },
      { 'name':'derivative_test_fixed',  'value':'first-order'   },
      { 'name':'max_num_iter_fixed',     'value':'100'           },
      { 'name':'print_level_fixed',      'value':'0'             },
      { 'name':'tolerance_fixed',        'value':'1e-12'         },

      { 'name':'derivative_test_random', 'value':'second-order'  },
      { 'name':'max_num_iter_random',    'value':'100'           },
      { 'name':'print_level_random',     'value':'0'             },
      { 'name':'tolerance_random',       'value':'1e-10'         }
   ]
   # ----------------------------------------------------------------------
   # subgroup_table
   subgroup_table = [ { 'subgroup':'world', 'group':'world' } ]
   # ----------------------------------------------------------------------
   # create database
   dismod_at.create_database(
      file_name,
      age_list,
      time_list,
      integrand_table,
      node_table,
      subgroup_table,
      weight_table,
      covariate_table,
      avgint_table,
      data_table,
      prior_table,
      smooth_table,
      nslist_dict,
      rate_table,
      mulcov_table,
      option_table
   )
   # ----------------------------------------------------------------------
# ===========================================================================
# Create database and run init, start, fit with zero sum for random effects
file_name = 'example.db'
example_db(file_name)
#
program = '../../devel/dismod_at'
dismod_at.system_command_prc([ program, file_name, 'init' ])
dismod_at.system_command_prc([ program, file_name, 'fit', 'both' ])
# -----------------------------------------------------------------------
# connect to database
connection      = dismod_at.create_connection(
   file_name, new = False, readonly = True
)
# -----------------------------------------------------------------------
# check the zero random effects solution
#
# get variable and fit_var tables
var_table     = dismod_at.get_table_dict(connection, 'var')
fit_var_table = dismod_at.get_table_dict(connection, 'fit_var')
rate_table    = dismod_at.get_table_dict(connection, 'rate')
node_table    = dismod_at.get_table_dict(connection, 'node')
time_table    = dismod_at.get_table_dict(connection, 'time')
#
# for node = north_america, canada, united_states, mexico
#  for time = 1990, 2010
#     for rate = iota, rho :
n_var = len(var_table)
assert n_var == 4 * 2 * 2
#
# initialize sum of random effects for each rate and time
sum_random = {
   'iota' : [ 0.0, 0.0 ],
   'rho'  : [ 0.0, 0.0 ]
}
# check of values uses the fact that the data density is Gaussian
count_random = 0
ok           = True
for var_id in range( n_var ) :
   var_type = var_table[var_id]['var_type']
   assert( var_type == 'rate' )
   #
   rate_id   = var_table[var_id]['rate_id']
   rate_name = rate_table[rate_id]['rate_name']
   #
   node_id   = var_table[var_id]['node_id']
   node_name = node_table[node_id]['node_name']
   #
   # note there are only two time_id values in time_table
   time_id   = var_table[var_id]['time_id']
   time      = time_table[time_id]['time']
   #
   value     = fit_var_table[var_id]['fit_var_value']
   #
   if node_name == 'north_america' :
      if rate_name == 'iota' :
         relerr = value / iota_parent - 1.0
      else :
         relerr = value / rho_parent - 1.0
   elif node_name == 'canada' :
      relerr = value / rate_effect_child  - 1.0
   elif node_name == 'mexico' :
      relerr = value - 0.0
   else :
      assert node_name == 'united_states'
      relerr = - value / rate_effect_child  - 1.0
   if abs(relerr) > 0.1 :
      print('node_name, relerr=', node_name, relerr)
      print('python_seed = ', python_seed)
      assert False
   if node_name != 'north_america' :
      sum_random[rate_name][time_id] += value
      count_random += 1
assert count_random == 3 * 2 * 2
for rate in [ 'iota', 'rho' ] :
   for time_id in [ 0 , 1 ] :
      if( abs( sum_random[rate][time_id] ) ) > 1e-9 :
         print('rate, sum random = ', rate, sum_random[rate][time_id] )
         print('python_seed = ', python_seed)
         assert False
#
# -----------------------------------------------------------------------
print('zsum_child_rate.py: OK')