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DarwinReporter: A reporting toolkit for pyDarwin

DarwinReporter_Overview.Rmd

The Certara.DarwinReporter package provides a Shiny application, in addition to various plotting and data summary functions for analyzing results of a pyDarwin automated model search.

This vignette provides an overview of an example R-based workflow for performing an automated search with NLME using Certara.RDarwin and analyzing results using the Certara.DarwinReporter package.

We will be using a pharmacokinetic dataset containing 16 subjects with single IV bolus dose for our search. The dataset is available within the Certara.RsNLME package.

head(Certara.RsNLME::pkData)
#> # A tibble: 6 × 8
#>   Subject Nom_Time Act_Time Amount  Conc   Age BodyWeight Gender
#>     <dbl>    <dbl>    <dbl>  <dbl> <dbl> <dbl>      <dbl> <chr> 
#> 1       1        0     0     25000  2010    22         73 male  
#> 2       1        1     0.26     NA  1330    22         73 male  
#> 3       1        1     1.1      NA   565    22         73 male  
#> 4       1        2     2.1      NA   216    22         73 male  
#> 5       1        4     4.13     NA   180    22         73 male  
#> 6       1        8     8.17     NA   120    22         73 male

We will begin by writing this dataset to a csv file in our current working directory:

write.csv(Certara.RsNLME::pkData, row.names = FALSE, file = "pkData.csv")

All candidate models assume linear elimination with parameterization set to “Clearance.” We will then search on:

  • Number of compartments: 1, 2, 3

  • Random effects for peripheral compartment parameters: V2, Cl2, V3, Cl3

  • Covariates: Age, BW, and Sex effect on Cl and V

  • Residual error model: Proportional or AdditiveMultiplicative

First, we will setup initial model sets to include 1, 2, and 3 compartments.

models <- get_PMLParametersSets(CompartmentsNumber = c(1, 2, 3))

Let us view the models:

models
#> PK1IVC 
#>  test() {
#>  cfMicro(A1, Cl / V)
#>  C = A1 / V
#>  dosepoint(A1, idosevar = A1Dose, infdosevar = A1InfDose, infratevar = A1InfRate)
#>  error(CEps = 0.1)
#>  observe(CObs = C * (1 + CEps))
#>  
#>  stparm(Cl = tvCl * exp( nCl ))
#>  fixef(tvCl= c(, 1, ))
#>  ranef(diag(nCl) = c(1))
#>  stparm(V = tvV * exp( nV ))
#>  fixef(tvV= c(, 1, ))
#>  ranef(diag(nV) = c(1))
#> 
#> } 
#> PK2IVC 
#>  test() {
#>  cfMicro(A1, Cl / V, Cl2 / V, Cl2 / V2)
#> C = A1 / V
#>  dosepoint(A1, idosevar = A1Dose, infdosevar = A1InfDose, infratevar = A1InfRate)
#>  error(CEps = 0.1)
#>  observe(CObs = C * (1 + CEps))
#>  
#>  stparm(Cl = tvCl * exp( nCl ))
#>  fixef(tvCl= c(, 1, ))
#>  ranef(diag(nCl) = c(1))
#>  stparm(V = tvV * exp( nV ))
#>  fixef(tvV= c(, 1, ))
#>  ranef(diag(nV) = c(1))
#>  stparm(Cl2 = tvCl2 * exp( nCl2 ))
#>  fixef(tvCl2= c(, 1, ))
#>  ranef(diag(nCl2) = c(1))
#>  stparm(V2 = tvV2 * exp( nV2 ))
#>  fixef(tvV2= c(, 1, ))
#>  ranef(diag(nV2) = c(1))
#> 
#> } 
#> PK3IVC 
#>  test() {
#>  cfMicro(A1, Cl / V, Cl2 / V, Cl2 / V2, Cl3 / V, Cl3 / V3)
#>  C = A1 / V
#>  dosepoint(A1, idosevar = A1Dose, infdosevar = A1InfDose, infratevar = A1InfRate)
#>  error(CEps = 0.1)
#>  observe(CObs = C * (1 + CEps))
#>  
#>  stparm(Cl = tvCl * exp( nCl ))
#>  fixef(tvCl= c(, 1, ))
#>  ranef(diag(nCl) = c(1))
#>  stparm(V = tvV * exp( nV ))
#>  fixef(tvV= c(, 1, ))
#>  ranef(diag(nV) = c(1))
#>  stparm(Cl2 = tvCl2 * exp( nCl2 ))
#>  fixef(tvCl2= c(, 1, ))
#>  ranef(diag(nCl2) = c(1))
#>  stparm(V2 = tvV2 * exp( nV2 ))
#>  fixef(tvV2= c(, 1, ))
#>  ranef(diag(nV2) = c(1))
#>  stparm(Cl3 = tvCl3 * exp( nCl3 ))
#>  fixef(tvCl3= c(, 1, ))
#>  ranef(diag(nCl3) = c(1))
#>  stparm(V3 = tvV3 * exp( nV3 ))
#>  fixef(tvV3= c(, 1, ))
#>  ranef(diag(nV3) = c(1))
#> 
#> }

Next, we will search whether peripheral compartment parameters, V2, Cl2, V3, Cl3, have random effects by specifying the Name of the random effect for corresponding structural parameter, and setting the State argument to "Searched".

models <- models |>
  modify_Omega(Name = "nV2", State = "Searched") |>
  modify_Omega(Name = "nCl2", State = "Searched") |>
  modify_Omega(Name = "nV3", State = "Searched") |>
  modify_Omega(Name = "nCl3", State = "Searched")

Now, we will introduce a few covariates (Age, BW, and Sex) into the search space in order to explore various covariate effects across structural parameters V and Cl.

models <- models |>
  add_Covariate(Name = "Age", StParmNames = c("V", "Cl"), State = "Searched") |>
  add_Covariate(Name = "BW", StParmNames = c("V", "Cl"), State = "Searched", Center = 70) |>
  add_Covariate(Name = "Sex", Type = "Categorical", StParmNames = c("V", "Cl"), State = "Searched", Categories = c(0, 1))

Finally, we will add both a Proportional and Additive-Multiplicative error model to the search space using the SigmasChosen argument in the function modify_Observation():

models <- models |>
  modify_Observation(
    ObservationName = "CObs",
    SigmasChosen = Sigmas(
      AdditiveMultiplicative = list(PropPart = 0.1, AddPart = 0.01),
      Proportional = 0.1
    )
  )

Before running the search, we first must configure a few options for pyDarwin, such as the algorithm, number of generations/iterations (num_generations), the number of models in each generation (population_size), and the working_dir. For this example, we will additionally perform a final downhill search after the generations for GA have completed.

optionSetup <- create_pyDarwinOptions(
  algorithm = "GA",
  num_generations = 10,
  population_size = 10,
  downhill_period = 0,
  local_2_bit_search = FALSE,
  final_downhill_search = TRUE,
  working_dir = getwd(),
  remove_temp_dir = FALSE
)

Note, pyDarwin requires 3 input files for execution - template.txt, tokens.json, and options.json files. RDarwin provides functions to easily generate these files:

We will write the options.json file using values in our optionSetup with the following command:

write_pyDarwinOptions(pyDarwinOptions = optionSetup)

Similarly, we will write the template.txt file and tokens.json file using the command below, passing the models object we created to the PMLParameterSets argument:

write_ModelTemplateTokens(Description = "Search-numCpt-PeripherialRanef-3CovariatesOnClV-RSE",
                          Author = "Certara",
                          DataFilePath = "pkData.csv",
                          DataMapping = c(id = "Subject", time = "Act_Time", AMT = "Amount", CObs = "Conc", Age = "Age", BW = "BodyWeight", Sex = "Gender(female = 0, male = 1)"),
                          PMLParametersSets = models
                          )

Note in the above command, we specified the path to our data file using the DataFilePath argument and mapped required model variables to column names in the data file using the DataMapping argument. See ?Certara.RDarwin::get_ModelTermsToMap to list required model variables for given search space.

Now we are ready to run the search.

job <- run_pyDarwin(InterpreterPath = "~/.venv/Scripts/python.exe", Wait = TRUE)
[17:55:54] Model run priority is below_normal
[17:55:54] Using darwin.MemoryModelCache
[17:55:54] Writing intermediate output to C:/Workspace/Darwin/output\results.csv
[17:55:54] Models will be saved in C:/Workspace/Darwin\models.json
[17:55:54] Template file found at template.txt
[17:55:54] Tokens file found at tokens.json
[17:55:54] Algorithm: GA
[17:55:54] Engine: NLME
[17:55:54] random_seed: 11
[17:55:54] Project dir: C:\Workspace\Darwin
[17:55:54] Data dir: C:\Workspace\Darwin
[17:55:54] Project working dir: C:/Workspace/Darwin
[17:55:54] Project temp dir: C:/Workspace/Darwin\temp
[17:55:54] Project output dir: C:/Workspace/Darwin/output
[17:55:54] Key models dir: C:/Workspace/Darwin\key_models
[17:55:54] Search space size: 6144
[17:55:54] Estimated number of models to run: 230
[17:55:54] NLME found: C:/Program Files/Certara/NLME_Engine
[17:55:54] GCC found: C:/Program Files/Certara/mingw64
[17:55:54] Search start time: Tue Nov 14 17:55:54 2023
[17:55:54] Starting generation 1
[17:55:54] Not using Post Run R code
[17:55:54] Not using Post Run Python code
[17:55:54] Checking files in C:\Workspace\Darwin\temp\01\03
[17:56:19] Generation =    01, Model     3,           Done,    fitness =  1952.736,    message = No important warnings
[17:56:21] Generation =    01, Model     4,           Done,    fitness =  1639.444,    message = No important warnings
[17:56:28] Generation =    01, Model     1,           Done,    fitness =  1690.038,    message = No important warnings
[17:56:35] Generation =    01, Model     2,           Done,    fitness =  1383.304,    message = No important warnings
[17:56:49] Generation =    01, Model     5,           Done,    fitness =  1646.580,    message = No important warnings
[17:56:51] Generation =    01, Model     6,           Done,    fitness =  1363.718,    message = No important warnings
[17:56:52] Generation =    01, Model     7,           Done,    fitness =  1351.912,    message = No important warnings
[17:57:05] Generation =    01, Model     8,           Done,    fitness =  1701.238,    message = No important warnings
[17:57:07] Generation =    01, Model     9,           Done,    fitness =  1824.660,    message = No important warnings
[17:57:15] Generation =    01, Model    10,           Done,    fitness =  1460.988,    message = No important warnings
[17:57:15] Current generation best genome = [0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0], best fitness = 1351.9120
[17:57:15] Best overall fitness = 1351.912000, iteration 01, model 7
[17:57:15] No change in fitness for 1 generations, best fitness = 1351.9120
[17:57:15] Starting generation 2
[17:57:15] Time elapsed: 1.4 min.
[17:57:15] Estimated time remaining: 29 min.
...

[18:14:55] Done with final downhill step. best fitness = 1311.942
[18:14:55] Final output from best model is in C:/Workspace/Darwin/output\FinalResultFile.txt
[18:14:55] Number of considered models: 230
[18:14:55] Number of models that were run during the search: 141
[18:14:55] Number of unique models to best model: 91
[18:14:55] Time to best model: 12.2 minutes
[18:14:55] Best overall fitness: 1311.942000, iteration FND02, model 10
[18:14:55] Elapsed time: 19.0 minutes 

[18:14:55] Search end time: Tue Nov 14 18:14:55 2023

[18:14:55] Key models:
[18:14:55] Generation =    01, Model     7,           Done,    fitness =  1351.912,    message = No important warnings
[18:14:55] Generation =    04, Model     9,           Done,    fitness =  1338.992,    message = No important warnings
[18:14:55] Generation =    05, Model     3,           Done,    fitness =  1334.540,    message = No important warnings
[18:14:55] Generation =    06, Model     9,           Done,    fitness =  1324.540,    message = No important warnings
[18:14:55] Generation = FND01, Model     8,           Done,    fitness =  1317.292,    message = No important warnings
[18:14:55] Generation = FND02, Model    10,           Done,    fitness =  1311.942,    message = No important warnings

Note: The above output is abbreviated. Only results from generation 1 and final lines are displayed.

Analyze Results

We will use the function darwin_data() to import our results into R:

ddb <- darwin_data(project_dir = getwd())

We can plot fitness vs iteration:

A plot of fitness vs iteration.

Or the penalty composition of min fitness by iteration:

fitness_penalties_vs_iteration(ddb, group_penalties = FALSE)

A plot of the penalty composition of minimum fitness by iteration.

If we want to explore model diagnostic plots for key models, we can use the function import_key_models(), specifying the path to the “key_models” folder created by pyDarwin.

ddb <- ddb |>
  import_key_models(dir = file.path(getwd(), "key_models"))

Using the function darwinReportUI(), we can launch the Shiny GUI and easily explore the search results.

A gif demonstrating plot customization options in the VPCResults Shiny GUI.

Within the application, users can explore model diagnostic plots across all key models, including the final model, create and customize GOF plots and tables, including generating the underlying R code to reproduce, and download R Markdown reports!