StepTwo function

Select M-X pairs via SIS

An auxiliary function which selects M-X paris using SIS.

StepTwo(
  X,
  M,
  time,
  status,
  X_sel_Y_s1,
  M_X_s1,
  M_sel_Y_s1,
  SIS_thres = "n/log(n)"
)

Arguments

• X: An n by p matrix of exposures.
• M: An n by p matrix of mediators.
• time: A vector of survival time of samples.
• status: A vector of status indicator: 0=alive, 1=dead.
• X_sel_Y_s1: Outputs from StepOne: A vector of selected X for Y.
• M_X_s1: Outputs from StepOne: A list of selected X for M.
• M_sel_Y_s1: Outputs from StepOne: A vector of selected M for Y.
• SIS_thres: SIS thresholds. Default is "n/log(n)". Other options include "n-1", "n/2log(n)", "2n/log(n)", "3n/log(n)".

Returns

A data table with selected M, X pairs and related effect size.

Examples

data(example_dat)
surv_dat <- example_dat$surv_dat
res_step1 <- StepOne(X = example_dat$X, M = example_dat$M, time = surv_dat$time,
status = surv_dat$status, model_option = "MCP")
M_X_sel_s2 <- StepTwo(X = example_dat$X, M = example_dat$M, time = surv_dat$time,
status = surv_dat$status, X_sel_Y_s1 = res_step1$X_sel_Y_s1, M_X_s1 = res_step1$M_X_s1,
M_sel_Y_s1 = res_step1$M_sel_Y_s1)