Read symptom combinations from a JSON file

Imports symptom combinations from a JSON file previously created by write_combinations. The returned list contains all fields needed to apply the combinations to new data via apply_symptom_combinations.

Usage

read_combinations(file)

Arguments

file

Character string. Path to the JSON file to read.

Value

A named list with the following elements:

combinations

List of numeric vectors. Each vector contains symptom indices for one combination.

combination_ids

Character vector of canonical combination IDs (sorted symptom indices joined by underscores, e.g. "4_6_7_17_19_20"). Computed from the combinations if not present in the file (backward compatibility with files created before v0.2.1).

ranks

Integer vector of ranks (1 = best). Computed from list position if not present in the file.

n_required

Numeric. Number of symptoms required for a positive diagnosis.

clusters

NULL for non-hierarchical combinations, or a named list of numeric vectors defining the cluster structure.

parameters

Named list with additional metadata: n_symptoms and score_by (may be NULL if not recorded).

description

Character string with the user-provided description.

ptsddiag_version

Character string indicating which package version created the file.

created_at

Character string with the creation timestamp.

The combinations, n_required, and clusters elements can be passed directly to apply_symptom_combinations:

spec <- read_combinations("my_combos.json")
result <- apply_symptom_combinations(
  data, spec$combinations, spec$n_required, spec$clusters
)

Details

The function validates the imported data using the same checks as apply_symptom_combinations, ensuring that the file contains valid combinations, a valid n_required threshold, and (if present) a valid cluster structure.

If the file was created with a different version of PTSDdiag than the one currently installed, an informational message is displayed.

See also

write_combinations to export combinations to a JSON file.

apply_symptom_combinations to apply imported combinations to new data.

Examples

# Write example combinations
my_combos <- list(
  c(1, 6, 8, 10, 15, 19),
  c(2, 7, 9, 11, 16, 20)
)
tmp <- tempfile(fileext = ".json")
write_combinations(my_combos, tmp, n_required = 4,
                   score_by = "false_cases")
#> Combinations written to /tmp/RtmpGlFb3Z/file1ca22192d599.json

# Read them back
spec <- read_combinations(tmp)
spec$combinations
#> [[1]]
#> [1]  1  6  8 10 15 19
#> 
#> [[2]]
#> [1]  2  7  9 11 16 20
#> 
spec$n_required
#> [1] 4

# Apply to data (example workflow)
# comparison <- apply_symptom_combinations(
#   new_data, spec$combinations, spec$n_required, spec$clusters
# )

# Clean up
unlink(tmp)