Merge pull request #75 from cjvanlissa/master

Add merge S3 method for varimp, to facilitate piecewise analyses

R/mergeVarimp.R

@@ -0,0 +1,32 @@
+#' @exportS3Method merge semforest.varimp
+merge.semforest.varimp <- function(...){
+  if (length(list(...))<2) stop("Need at least two arguments to merge!")
+  return(.merge_varimp( list(...) ))
+}
+
+.merge_varimp <- function (varimp_list) 
+{
+  numtrees <- sapply(varimp_list, function(x){length(x$ll.baselines)})
+  numfeatures <- sapply(varimp_list, function(x){dim(x$importance)[2]})
+  if(length(unique(numfeatures)) > 1) stop("Not all semforest.varimp objects have the same number of variables.")
+  varnames <- sapply(varimp_list, `[[`, "var.names")
+  if(any(apply(varnames, 1, function(x){length(unique(x))}) > 1)) stop("Not all var.names are the same.")
+  out <- list(
+    ll.baselines = vector("numeric", sum(numtrees)),
+    importance = matrix(nrow = sum(numtrees), ncol = numfeatures[1]),
+    elapsed = varimp_list[[1]]$elapsed,
+    var.names = varimp_list[[1]]$var.names
+  )
+  colnames(out$importance) <- colnames(varimp_list[[1]]$importance)
+  for (i in 2:length(varimp_list)) {
+    out$elapsed <- out$elapsed + varimp_list[[i]]$elapsed
+  }
+  index_trees <- c(0, numtrees, 0)
+  for (i in 1:length(varimp_list)) {
+    indcs <- (sum(index_trees[1:i])+1):sum(index_trees[1:i+1])
+    out$ll.baselines[indcs] <- varimp_list[[i]]$ll.baselines
+    out$importance[indcs, 1:numfeatures[1]] <- varimp_list[[i]]$importance
+  }
+  class(out) <- class(varimp_list[[1]])
+  return(out)
+}