'update'

[aggexp.git] / pkg / R / m_RegressionTree.R

diff --git a/pkg/R/m_RegressionTree.R b/pkg/R/m_RegressionTree.R
new file mode 100644 (file)
index 0000000..d51e408
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+++ b/pkg/R/m_RegressionTree.R
@@ -0,0 +1,36 @@
+#' @include b_Algorithm.R
+
+#' @title Regression Tree
+#'
+#' @description Regression Tree using the \code{tree} package.
+#' Inherits \code{\link{Algorithm}}
+#'
+#' @field nleaf Number of leaf nodes after pruning. Default: Inf (no pruning)
+#'
+RegressionTree = setRefClass(
+       Class = "RegressionTree",
+
+       fields = c(
+               nleaf = "numeric"
+       ),
+
+       contains = "Algorithm",
+
+       methods = list(
+               initialize = function(...)
+               {
+                       callSuper(...)
+                       if (length(nleaf) == 0 || nleaf < 1)
+                               nleaf <<- Inf
+               },
+               predict_noNA = function(XY, x)
+               {
+                       require(tree, quietly=TRUE)
+                       rt = tree(Measure ~ ., data=XY)
+                       treeSize = sum( rt$frame[["var"]] == "<leaf>" )
+                       if (treeSize > nleaf)
+                               rt = prune.tree(rt, best = nleaf)
+                       return (stats::predict(rt, as.data.frame(x)))
+               }
+       )
+)