From e53085a645bfd4f71ecc4f6a828ae65a5f1be092 Mon Sep 17 00:00:00 2001
From: Kim Albertsson <ketost@gmail.com>
Date: Mon, 17 Sep 2018 20:29:51 +0200
Subject: [PATCH] [TMVA] BDTG -- Parallelise application get values
Simple to //-ise over number of output classes. Doing the same over
number of trees seems to yield no benefit for ~1000 depth=3 tree so this
was skipped (binary and multi class).
Optimal would be to //-ise over events, but the current design makes
this tricky.
---
tmva/tmva/src/MethodBDT.cxx | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/tmva/tmva/src/MethodBDT.cxx b/tmva/tmva/src/MethodBDT.cxx
index e059771c2da..72f49525985 100644
--- a/tmva/tmva/src/MethodBDT.cxx
+++ b/tmva/tmva/src/MethodBDT.cxx
@@ -2502,6 +2502,18 @@ const std::vector<Float_t>& TMVA::MethodBDT::GetMulticlassValues()
UInt_t nClasses = DataInfo().GetNClasses();
std::vector<Double_t> temp(nClasses);
auto forestSize = fForest.size();
+
+ #ifdef R__USE_IMT
+ std::vector<TMVA::DecisionTree *> forest = fForest;
+ auto get_output = [&e, &forest, &temp, forestSize, nClasses](UInt_t iClass) {
+ for (UInt_t itree = iClass; itree < forestSize; itree += nClasses) {
+ temp[iClass] += forest[itree]->CheckEvent(e, kFALSE);
+ }
+ };
+
+ TMVA::Config::Instance().GetThreadExecutor()
+ .Foreach(get_output, ROOT::TSeqU(nClasses));
+ #else
// trees 0, nClasses, 2*nClasses, ... belong to class 0
// trees 1, nClasses+1, 2*nClasses+1, ... belong to class 1 and so forth
UInt_t classOfTree = 0;
@@ -2509,6 +2521,7 @@ const std::vector<Float_t>& TMVA::MethodBDT::GetMulticlassValues()
temp[classOfTree] += fForest[itree]->CheckEvent(e, kFALSE);
if (++classOfTree == nClasses) classOfTree = 0; // cheap modulo
}
+ #endif
// we want to calculate sum of exp(temp[j] - temp[i]) for all i,j (i!=j)
// first calculate exp(), then replace minus with division.
--
GitLab