user_fit_meas_noise.py#

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Group Measurement Noise Covariate Multipliers, Gamma#

Purpose#

This example demonstrates fitting Group Covariate Multipliers that effect the measurement noise.

Random Effects#

There are no random effects in this example.

Iota#

The value iota_true is the simulated true rate for iota. The prior for iota is uniform prior with lower limit iota_true / 100 and upper limit one. The mean for the prior is iota_true / 10 (this is only used as a starting point for the optimization). There is only one grid point (one model_variable ) corresponding to iota , hence it is constant in age and time.

Other Rates#

For this example the other rates are all zero. This is specified by setting the parent_smooth_id and child_smooth_id to null for the other rates.

Subgroup Table#

The data is divided into two groups. The first group is hospital data and the second group is survey data.

Covariate Multiplier#

There is one covariate multiplier on the covariate column one and the rate iota . This is a measurement noise covariate multiplier gamma that only effects the survey data. The prior for this multiplier is a uniform on the interval from zero to 10 * gamma_true . The true value for this multiplier, used to simulate data, is called gamma_true . The mean for the prior is gamma_true / 10 (this is only used as a starting point for the optimization). There is only one grid point (one model variable) corresponding to the covariate multiplier, hence it is constant in age and time.

Data#

There are n_data measurements of Sincidence. The hospital data has standard deviation meas_std . The survey data has addition noise determine by the covariate effect.

meas_noise_effect#

see meas_noise_effect . The function gamma_true depends on this option, this in turn affects the priors. Hence the data base must be recreated for each choice of this option

Scaling Gamma#

The function gamma_true() shows on the scaling of gamma depends on the value of meas_noise_effect .

Source Code#

# You can changed the values below and rerun this program
iota_true          = 0.01
scale_gamma_true   = 2.0
n_data             = 4000
meas_std           = iota_true * 0.5
# You can changed the values above and rerun this program
# ---------------------------------------------------------------------------
def gamma_true() :
   gamma_dict = {
      'add_std_scale_none' : scale_gamma_true * meas_std ,
      'add_std_scale_all'  : scale_gamma_true ,
      'add_var_scale_none' : scale_gamma_true * meas_std * meas_std ,
      'add_var_scale_all'  : scale_gamma_true ,
   }
   return gamma_dict[meas_noise_effect]
# ----------------------------------------------------------------------------
import sys
import os
import copy
test_program = 'example/user/fit_meas_noise.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')
# ------------------------------------------------------------------------
# Note that the a, t values are not used for this example
def example_db (file_name, meas_noise_effect) :
   # note that the a, t values are not used for this case
   def fun_iota(a, t) :
      return ('prior_iota', None, None)
   def fun_gamma(a, t) :
      return ('prior_gamma', None, None)
   # ----------------------------------------------------------------------
   # age table:
   age_list    = [ 0.0, 100.0 ]
   #
   # time table:
   time_list   = [ 1990.0, 2010.0 ]
   #
   # integrand table:
   integrand_table = [
       { 'name': 'Sincidence' }
   ]
   #
   # node table:
   node_table = [ { 'name':'world', 'parent':'' } ]
   #
   # subgroup_table
   subgroup_table = [
      { 'subgroup':'hospital', 'group':'hospital' },
      { 'subgroup':'survey',   'group':'survey' },
   ]
   #
   # weight table:
   weight_table = list()
   #
   # covariate table:
   covariate_table = [
      {'name':'one', 'reference':0.0}
   ]
   #
   # mulcov table:
   mulcov_table = [
      {  # covariate multiplier effects Sincidence survey data measurements
         'covariate': 'one',
         'type':      'meas_noise',
         'effected':  'Sincidence',
         'group':     'world',
         'group':     'survey',
         'smooth':    'smooth_gamma',
         'subsmooth': None
      }
   ]
   #
   # avgint table: empty
   avgint_table = list()
   #
   # nslist_dict:
   nslist_dict = dict()
   # ----------------------------------------------------------------------
   # data table:
   data_table = list()
   # values that are the same for all data rows
   row = {
      'meas_value':  0.0,             # not used (will be simulated)
      'density':     'gaussian',
      'weight':      '',
      'hold_out':     False,
      'time_lower':   2000.,
      'time_upper':   2000.,
      'integrand':   'Sincidence',
      'meas_std':     meas_std,
      'node':        'world',
      'subgroup':    'world',
      'one':          1.0
   }
   # values that change between rows:
   for data_id in range( n_data ) :
      if data_id % 2 == 0 :
         row['subgroup'] = 'hospital'
      else :
         row['subgroup'] = 'survey'
      #
      fraction         = data_id / float(n_data-1)
      age              = age_list[0] + (age_list[-1] - age_list[0])*fraction
      row['age_lower'] = age
      row['age_upper'] = age
      data_table.append( copy.copy(row) )
   #
   # ----------------------------------------------------------------------
   # prior_table
   prior_table = [
      { # prior_iota
         'name':     'prior_iota',
         'density':  'uniform',
         'lower':    iota_true / 100.0,
         'upper':    1.0,
         'mean':     iota_true / 10.0
      },{ # prior_gamma
         'name':     'prior_gamma',
         'density':  'uniform',
         'lower':    0.0,
         'upper':    10.0 * gamma_true(),
         'mean':     gamma_true() / 10.0
      }
   ]
   # ----------------------------------------------------------------------
   # smooth table
   name           = 'smooth_iota'
   fun            = fun_iota
   age_id         = 0
   time_id        = 0
   smooth_table = [
      {'name':name, 'age_id':[age_id], 'time_id':[time_id], 'fun':fun }
   ]
   name = 'smooth_iota'
   #
   name = 'smooth_gamma'
   fun  = fun_gamma
   smooth_table.append(
      {'name':name, 'age_id':[age_id], 'time_id':[time_id], 'fun':fun }
   )
   # ----------------------------------------------------------------------
   # rate table:
   rate_table = [
      {  'name':          'iota',
         'parent_smooth': 'smooth_iota',
         'child_smooth':  None
      }
   ]
   # ----------------------------------------------------------------------
   # option_table
   option_table = [
      { 'name':'meas_noise_effect',      'value':meas_noise_effect   },
      { 'name':'rate_case',              'value':'iota_pos_rho_zero' },
      { 'name':'parent_node_name',       'value':'world'             },
      { 'name':'random_seed',            'value':'0'                 },
      { 'name':'zero_sum_child_rate',    'value':'iota'              },

      { 'name':'quasi_fixed',            'value':'false'             },
      { 'name':'derivative_test_fixed',  'value':'second-order'      },
      { 'name':'max_num_iter_fixed',     'value':'100'               },
      { 'name':'print_level_fixed',      'value':'0'                 },
      { 'name':'tolerance_fixed',        'value':'1e-10'             }
   ]
   # ----------------------------------------------------------------------
   # 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
   )
   # ----------------------------------------------------------------------
   return
# ===========================================================================
# Run the init command to create the var table
file_name = 'example.db'
for meas_noise_effect in [
   'add_std_scale_none',
   'add_std_scale_all',
   'add_var_scale_none',
   'add_var_scale_all',
] :
   print(meas_noise_effect)
   example_db(file_name, meas_noise_effect)
   #
   program = '../../devel/dismod_at'
   dismod_at.system_command_prc([ program, file_name, 'init' ])
   # -----------------------------------------------------------------------
   # read database
   connection      = dismod_at.create_connection(
      file_name, new = False, readonly = False
   )
   var_table       = dismod_at.get_table_dict(connection, 'var')
   rate_table      = dismod_at.get_table_dict(connection, 'rate')
   integrand_table = dismod_at.get_table_dict(connection, 'integrand')
   covariate_table = dismod_at.get_table_dict(connection, 'covariate')
   node_table      = dismod_at.get_table_dict(connection, 'node')
   # -----------------------------------------------------------------------
   # truth table:
   tbl_name     = 'truth_var'
   col_name     = [ 'truth_var_value' ]
   col_type     = [ 'real' ]
   row_list     = list()
   var_id2true  = list()
   for var_id in range( len(var_table) ) :
      var_info        = var_table[var_id]
      truth_var_value = None
      var_type        = var_info['var_type']
      if var_type == 'mulcov_meas_noise' :
         integrand_id  = var_info['integrand_id']
         integrand_name = integrand_table[integrand_id]['integrand_name']
         assert integrand_name == 'Sincidence'
         #
         covariate_id   = var_info['covariate_id']
         covariate_name = covariate_table[covariate_id]['covariate_name' ]
         assert( covariate_name == 'one' )
         #
         truth_var_value = gamma_true()
      else :
         assert( var_type == 'rate' )
         rate_id   = var_info['rate_id']
         rate_name = rate_table[rate_id]['rate_name']
         assert rate_name == 'iota'
         #
         node_id   = var_info['node_id']
         node_name = node_table[node_id]['node_name']
         assert node_name == 'world'
         #
         truth_var_value = iota_true
      #
      var_id2true.append( truth_var_value )
      row_list.append( [ truth_var_value ] )
   dismod_at.create_table(connection, tbl_name, col_name, col_type, row_list)
   connection.close()
   # -----------------------------------------------------------------------
   # Simulate then fit the data
   dismod_at.system_command_prc([ program, file_name, 'simulate', '1' ])
   dismod_at.system_command_prc([
      program, file_name, 'set', 'start_var', 'truth_var'
   ])
   dismod_at.system_command_prc([
      program, file_name, 'set', 'start_var', 'truth_var'
   ])
   dismod_at.system_command_prc([ program, file_name, 'fit', 'fixed' , '0' ])
   # -----------------------------------------------------------------------
   # check fit results
   connection   = dismod_at.create_connection(
      file_name, new = False, readonly = True
   )
   fit_var_table = dismod_at.get_table_dict(connection, 'fit_var')
   connection.close()
   #
   max_error    = 0.0
   for var_id in range( len(var_table) ) :
      row        = fit_var_table[var_id]
      fit_value  = row['fit_var_value']
      true_value = var_id2true[var_id]
      assert( true_value != 0.0 )
      # remove # at start of next line to see relative error values
      # print(true_value, fit_value, fit_value / true_value - 1.0 )
      max_error = max( abs(fit_value / true_value - 1.0), max_error)
   if max_error > 1e-1 :
      print('max_error = ', max_error)
      assert(False)
# -----------------------------------------------------------------------------
print('fit_meas_noise.py: OK')
# -----------------------------------------------------------------------------