+//______________________________________________________________________________________________
+UInt_t AliTPCPreprocessor::MapGasComposition(TMap* dcsAliasMap)
+{
+
+ // extract DCS HV maps. Perform fits to save space
+
+ UInt_t result=0;
+ TMap *map = fGasComposition->ExtractDCS(dcsAliasMap);
+ if (map) {
+ fHighVoltage->ClearFit();
+ fHighVoltage->RemoveGraphDuplicates(kGasCompositionDifference);
+ // don't keep new point if too similar to previous one
+ fHighVoltage->SetGraph(map);
+ } else {
+ Log("No gas composition recordings extracted. \n");
+ result=9;
+ }
+ delete map;
+
+ // Now store the final CDB file
+
+ if ( result == 0 ) {
+ AliCDBMetaData metaData;
+ metaData.SetBeamPeriod(0);
+ metaData.SetResponsible("Haavard Helstrup");
+ metaData.SetAliRootVersion(ALIROOT_BRANCH);
+ metaData.SetComment("Preprocessor AliTPC data base entries.");
+
+ Bool_t storeOK = Store("Calib", "GasComposition", fGasComposition, &metaData, 0, kFALSE);
+ if ( !storeOK ) result=1;
+
+ }
+
+ return result;
+
+}
+