fixed broken score testing implementation -- closes #265

R/scoreTestGEE.R

@@ -8,7 +8,8 @@
 #' @param mod.0 The model under the null hypothesis. Must be of class \code{geem}. Defaults to NULL.
 #' @param alt.df The dataframe used to fit the alternative model. Defaults to NULL. 
 #' @param null.df The dataframe used to fit the null model. Defaults to NULL. 
-#' @param sandwich.var Boolean specifying whether the sandwich variance-covariance matrix should be used. Defaults to FALSE.
+#' @param id.vec A vector of subject IDs to use as input to \code{\link{marge2}}. Defaults to NULL.
+#' @param cor.structure A string specifying the working correlation structure used to fit each model. Must be one of "ar1", "independence", or "exchangeable". Defaults to "ar1".
 #' @return A list containing the Score test statistic, a \emph{p}-value, and the degrees of freedom used in the test.
 #' @details
 #' \itemize{
@@ -23,9 +24,10 @@ scoreTestGEE <- function(mod.1 = NULL,
                          mod.0 = NULL, 
                          alt.df = NULL, 
                          null.df = NULL, 
-                         sandwich.var = FALSE) {
+                         id.vec = NULL, 
+                         cor.structure = "ar1") {
   # check inputs 
-  if (is.null(mod.1) || is.null(mod.0) || is.null(alt.df) || is.null(null.df)) { stop("Please provide all inputs to scoreTestGEE().") }
+  if (is.null(mod.1) || is.null(mod.0) || is.null(alt.df) || is.null(null.df) || is.null(id.vec)) { stop("Please provide all inputs to scoreTestGEE().") }
   if (inherits(mod.1, "try-error") || inherits(mod.0, "try-error")) {
     res <- list(Score_Stat = NA_real_,
                 DF = NA_real_,
@@ -43,17 +45,39 @@ scoreTestGEE <- function(mod.1 = NULL,
                 P_Val = 1,
                 Notes = NA_character_)
   } else {
+    rho <- summary(mod.0)$alpha
+    sigma2 <- summary(mod.0)$phi
     X_null <- stats::model.matrix(mod.0, data = null.df)
     X_alt <- stats::model.matrix(mod.1, data = alt.df)
     residuals_null <- null.df$Y - exp(stats::predict(mod.0))
-    if (sandwich.var) {
-      V_null <- as.matrix(mod.0$var)
-    } else {
-      V_null <- as.matrix(mod.0$naiv.var)
+    p_alt <- ncol(X_alt)
+    U <- rep(0, p_alt)
+    V_U <- matrix(0, nrow = p_alt, ncol = p_alt)
+    groups <- unique(id.vec)
+    for (i in seq(groups)) {
+      group_indices <- which(id.vec == groups[i])
+      X_alt_i <- X_alt[group_indices, , drop = FALSE]
+      residuals_i <- residuals_null[group_indices]
+      n_i <- length(group_indices)
+      if (cor.structure == "independence") {
+        R_i <- diag(1, nrow = n_i, ncol = n_i)
+      } else if (cor.structure == "exchangeable") {
+        R_i <- matrix(rho, nrow = n_i, ncol = n_i)
+        diag(R_i) <- 1
+      } else if (cor.structure == "ar1") {
+        R_i <- matrix(rho^abs(outer(seq(n_i), seq(n_i), "-")), nrow = n_i, ncol = n_i)
+      }
+      V_i <- sigma2 * R_i
+      R_i_inv <- try({ eigenMapMatrixInvert(V_i) }, silent = TRUE)
+      if (inherits(R_i_inv, "try-error")) {
+        R_i_inv <- eigenMapPseudoInverse(V_i)
+      }
+      X_alt_i_t <- t(X_alt_i)
+      U_i <- X_alt_i_t %*% (R_i_inv %*% residuals_i)
+      V_U_i <- X_alt_i_t %*% (R_i_inv %*% X_alt_i)
+      U <- U + U_i
+      V_U <- V_U + V_U_i
     }
-    X_alt_t <- t(X_alt)
-    U <- X_alt_t %*% residuals_null
-    V_U <- (X_alt_t * as.numeric(V_null)) %*% X_alt
     V_U_inv <- try({ eigenMapMatrixInvert(V_U) }, silent = TRUE)
     if (inherits(V_U_inv, "try-error")) {
       V_U_inv <- eigenMapPseudoInverse(V_U)

R/testDynamic.R

@@ -353,7 +353,8 @@ testDynamic <- function(expr.mat = NULL,
                                   mod.0 = null_mod, 
                                   alt.df = as.data.frame(marge_mod$basis_mtx), 
                                   null.df = null_mod_df, 
-                                  sandwich.var = ifelse(is.null(gee.bias.correction.method), FALSE, TRUE))
+                                  id.vec = id.vec[lineage_cells], 
+                                  cor.structure = cor.structure)
        }
      } else {
        test_res <- modelLRT(mod.1 = marge_mod,

tests/testthat/test_scLANE.R

@@ -47,6 +47,7 @@ withr::with_output_sink(tempfile(), {
                                 size.factor.offset = cell_offset,
                                 is.gee = TRUE,
                                 cor.structure = "ar1",
+                                gee.test = "score", 
                                 id.vec = sim_data$subject,
                                 n.cores = 2L)
   glmm_gene_stats <- testDynamic(sim_data,
@@ -139,7 +140,8 @@ withr::with_output_sink(tempfile(), {
   score_test <- scoreTestGEE(marge_mod_GEE_offset, 
                              mod.0 = null_mod_GEE, 
                              alt.df = as.data.frame(marge_mod_GEE_offset$basis_mtx), 
-                             null.df = data.frame(Y = counts_test[, 3]))
+                             null.df = data.frame(Y = counts_test[, 3]), 
+                             id.vec = sim_data$subject)
   # run GLMM model -- no offset
   glmm_mod <- fitGLMM(pt_test,
                       Y = counts_test[, 4],