Update Makefile

Makefile

@@ -43,7 +43,11 @@ $(EXAMPLE_DIR)/beta-delayed.dat: dataprinter nuchart.root Makefile
 	./$< nuchart.root a Z N QECp QBn QEC2p QB2n QECa QBa QECp_est QBn_est QEC2p_est QB2n_est QECa_est QBa_est half_life_stbl "Z <= 50" "N <= 50" > $@
 
 dataprinter: dataprinter.cxx
+ifeq ($(ROOTSYS), ) # source thisroot.sh if ROOTSYS is not defined
+	source $$(root-config --bindir)/thisroot.sh && $(CXX) $(CXXFLAGS) -o $@ $< $(LDLIBS)
+else
 	$(CXX) $(CXXFLAGS) -o $@ $< $(LDLIBS)
+endif
 
 $(EXPANSION_DIR)/expand-nuchart-QEC: $(EXPANSION_DIR)/expand-nuchart-QEC.cxx
 	$(CXX) $(CXXFLAGS) -o $@ $< $(LDLIBS)