Performs high-dimensional Cox proportional hazards regression using advanced regularization methods (LASSO, Ridge, Elastic Net, Adaptive LASSO) for survival data with many predictors. This method is essential when the number of variables is large relative to the number of observations, enabling variable selection and preventing overfitting in genomic, proteomic, or other high-dimensional clinical datasets.
Usage
highdimcox(
  data,
  elapsedtime,
  outcome,
  predictors,
  outcomeLevel = "1",
  regularization_method = "elastic_net",
  alpha_value = 0.5,
  cv_method = "cv_1se",
  cv_folds = 10,
  variable_selection = "none",
  stability_selection = FALSE,
  bootstrap_iterations = 500,
  stability_threshold = 0.8,
  show_regularization_path = TRUE,
  show_cv_plot = TRUE,
  show_variable_importance = TRUE,
  show_coefficients_table = TRUE,
  show_model_diagnostics = TRUE,
  showSummaries = FALSE,
  showExplanations = FALSE
)Arguments
- data
- the data as a data frame 
- elapsedtime
- Time variable for survival analysis 
- outcome
- Event indicator variable 
- predictors
- High-dimensional predictor variables 
- outcomeLevel
- Level of outcome variable indicating event 
- regularization_method
- Regularization method for high-dimensional Cox regression 
- alpha_value
- Alpha parameter for elastic net (0=ridge, 1=lasso) 
- cv_method
- Cross-validation method for lambda selection 
- cv_folds
- Number of cross-validation folds 
- variable_selection
- Additional variable selection method after regularization 
- stability_selection
- Perform stability selection for variable importance 
- bootstrap_iterations
- Number of bootstrap iterations for stability selection 
- stability_threshold
- Threshold for stability selection 
- show_regularization_path
- Display regularization path plot 
- show_cv_plot
- Display cross-validation error plot 
- show_variable_importance
- Display variable importance plot 
- show_coefficients_table
- Display selected coefficients table 
- show_model_diagnostics
- Display model diagnostic plots 
- showSummaries
- Generate natural language summaries 
- showExplanations
- Show methodology explanations 
Value
A results object containing:
| results$todo | a html | ||||
| results$modelSummary | a html | ||||
| results$selectedVariables | a table | ||||
| results$regularizationMetrics | a table | ||||
| results$stabilityResults | a table | ||||
| results$dimensionalityReduction | a table | ||||
| results$regularizationPath | an image | ||||
| results$cvPlot | an image | ||||
| results$variableImportance | an image | ||||
| results$modelDiagnostics | an image | ||||
| results$stabilityPlot | an image | ||||
| results$analysisSummary | a html | ||||
| results$methodExplanation | a html | 
Tables can be converted to data frames with asDF or as.data.frame. For example:
results$selectedVariables$asDF
as.data.frame(results$selectedVariables)
Examples
# Example 1: LASSO regularization for gene expression data
library(survival)
library(glmnet)
highdimcox(
    data = genomic_survival_data,
    elapsedtime = "time",
    outcome = "status",
    outcomeLevel = "1",
    predictors = c("gene1", "gene2", "gene3", "...gene1000"),
    regularization_method = "lasso",
    cv_folds = 10
)
# Example 2: Elastic Net with stability selection
highdimcox(
    data = protein_data,
    elapsedtime = "survival_time",
    outcome = "event",
    outcomeLevel = "1",
    predictors = c("protein1", "protein2", "...protein500"),
    regularization_method = "elastic_net",
    alpha_value = 0.5,
    stability_selection = TRUE,
    bootstrap_iterations = 500
)