diff --git a/numass-core/src/main/kotlin/inr/numass/data/storage/NumassDataFactory.kt b/numass-core/src/main/kotlin/inr/numass/data/storage/NumassDataFactory.kt
index f7217ccc..d8182bb7 100644
--- a/numass-core/src/main/kotlin/inr/numass/data/storage/NumassDataFactory.kt
+++ b/numass-core/src/main/kotlin/inr/numass/data/storage/NumassDataFactory.kt
@@ -35,11 +35,11 @@ class NumassDataFactory : DataFactory<NumassSet>(NumassSet::class.java) {
 
     override fun fill(builder: DataNodeEditor<NumassSet>, context: Context, meta: Meta) {
         runBlocking {
-            val storage = NumassDirectory.read(context,meta.getString("path")) as Storage
+            val storage = NumassDirectory.read(context, meta.getString("path")) as Storage
             storage.sequence().forEach { pair ->
                 val value = pair.second
                 if (value is NumassSet) {
-                    builder.putStatic(pair.first.unescaped, value)
+                    builder.putStatic(pair.first.unescaped, value, value.meta)
                 }
             }
         }
diff --git a/numass-main/src/main/kotlin/inr/numass/actions/MergeDataAction.kt b/numass-main/src/main/kotlin/inr/numass/actions/MergeDataAction.kt
index d9bbcc1f..79492706 100644
--- a/numass-main/src/main/kotlin/inr/numass/actions/MergeDataAction.kt
+++ b/numass-main/src/main/kotlin/inr/numass/actions/MergeDataAction.kt
@@ -45,12 +45,11 @@ object MergeDataAction : ManyToOneAction<Table, Table>("numass.merge", Table::cl
 
     override fun buildGroups(context: Context, input: DataNode<Table>, actionMeta: Meta): List<DataNode<Table>> {
         val meta = inputMeta(context, input.meta, actionMeta)
-        val groups: List<DataNode<Table>> = if (meta.hasValue("grouping.byValue")) {
+        return if (meta.hasValue("grouping.byValue")) {
             super.buildGroups(context, input, actionMeta)
         } else {
             GroupBuilder.byValue(MERGE_NAME, meta.getString(MERGE_NAME, input.name)).group(input)
         }
-        return groups
     }
 
     override fun execute(context: Context, nodeName: String, data: Map<String, Table>, meta: Laminate): Table {
diff --git a/numass-main/src/main/kotlin/inr/numass/scripts/PointSliceSpectrum.kt b/numass-main/src/main/kotlin/inr/numass/scripts/PointSliceSpectrum.kt
index ad5477eb..3dbb7cfd 100644
--- a/numass-main/src/main/kotlin/inr/numass/scripts/PointSliceSpectrum.kt
+++ b/numass-main/src/main/kotlin/inr/numass/scripts/PointSliceSpectrum.kt
@@ -23,7 +23,7 @@ fun main(args: Array<String>) {
     }
     //val rootDir = File("D:\\Work\\Numass\\data\\2017_05\\Fill_2")
 
-    val storage = NumassDirectory.read(context, "Fill_3_events") ?: error("Storage not found")
+    val storage = NumassDirectory.read(context, "Fill_3") ?: error("Storage not found")
 
 
     val analyzer = SmartAnalyzer()
@@ -34,7 +34,7 @@ fun main(args: Array<String>) {
 //        "window.up" to 1600
     }
 
-    val set = storage.provide("set_58", NumassSet::class.java).nullable ?: error("Set does not exist")
+    val set = storage.provide("set_4", NumassSet::class.java).nullable ?: error("Set does not exist")
 
     val frame = displayChart("slices").apply {
         plots.setType<DataPlot>()
diff --git a/numass-main/src/main/kotlin/inr/numass/scripts/threshold/FitAllWithPower.kt b/numass-main/src/main/kotlin/inr/numass/scripts/threshold/FitAllWithPower.kt
index e33c04f7..f0288b80 100644
--- a/numass-main/src/main/kotlin/inr/numass/scripts/threshold/FitAllWithPower.kt
+++ b/numass-main/src/main/kotlin/inr/numass/scripts/threshold/FitAllWithPower.kt
@@ -36,7 +36,7 @@ import inr.numass.data.storage.NumassDirectory
 import inr.numass.displayChart
 import inr.numass.subthreshold.Threshold
 
-fun main(args: Array<String>) {
+fun main() {
     val context = buildContext("NUMASS", NumassPlugin::class.java, JFreeChartPlugin::class.java) {
         rootDir = "D:\\Work\\Numass\\sterile\\2017_05_frames"
         dataDir = "D:\\Work\\Numass\\data\\2017_05_frames"
@@ -54,7 +54,7 @@ fun main(args: Array<String>) {
         "xLow" to 1000
         "xHigh" to 1300
         "upper" to 6000
-        "binning" to 20
+        "binning" to 32
         //"reference" to 18600
     }
 
diff --git a/numass-main/src/main/kotlin/inr/numass/scripts/threshold/FitWithPower.kt b/numass-main/src/main/kotlin/inr/numass/scripts/threshold/FitWithPower.kt
index f50f3171..97ed14d1 100644
--- a/numass-main/src/main/kotlin/inr/numass/scripts/threshold/FitWithPower.kt
+++ b/numass-main/src/main/kotlin/inr/numass/scripts/threshold/FitWithPower.kt
@@ -35,19 +35,24 @@ import inr.numass.subthreshold.Threshold
 
 fun main(args: Array<String>) {
     val context = buildContext("NUMASS", NumassPlugin::class.java, JFreeChartPlugin::class.java) {
-        rootDir = "D:\\Work\\Numass\\sterile\\2017_05"
-        dataDir = "D:\\Work\\Numass\\data\\2017_05"
+        rootDir = "D:\\Work\\Numass\\sterile\\2017_05_frames"
+        dataDir = "D:\\Work\\Numass\\data\\2017_05_frames"
         output = FXOutputManager() + DirectoryOutput()
     }
 
-    val storage = NumassDirectory.read(context, "Fill_2") as? FileStorage ?: error("Storage not found")
+    val storage = NumassDirectory.read(context, "Fill_3") as? FileStorage ?: error("Storage not found")
 
     val meta = buildMeta {
-        "delta" to -200
+        "delta" to -300
         "method" to "pow"
         "t0" to 15e3
-        "window.lo" to 400
-        "window.up" to 1600
+//        "window.lo" to 400
+//        "window.up" to 1600
+        "xLow" to 1000
+        "xHigh" to 1300
+        "upper" to 6000
+        "binning" to 32
+        //"reference" to 18600
     }
 
     val frame = displayChart("correction").apply {
diff --git a/numass-main/src/main/kotlin/inr/numass/tasks/NumassTasks.kt b/numass-main/src/main/kotlin/inr/numass/tasks/NumassTasks.kt
index 598943ab..d2889193 100644
--- a/numass-main/src/main/kotlin/inr/numass/tasks/NumassTasks.kt
+++ b/numass-main/src/main/kotlin/inr/numass/tasks/NumassTasks.kt
@@ -1,10 +1,7 @@
 package inr.numass.tasks
 
 import hep.dataforge.configure
-import hep.dataforge.data.CustomDataFilter
-import hep.dataforge.data.DataSet
-import hep.dataforge.data.DataTree
-import hep.dataforge.data.DataUtils
+import hep.dataforge.data.*
 import hep.dataforge.io.output.stream
 import hep.dataforge.io.render
 import hep.dataforge.meta.Meta
@@ -22,6 +19,7 @@ import hep.dataforge.stat.fit.FitResult
 import hep.dataforge.stat.models.XYModel
 import hep.dataforge.tables.*
 import hep.dataforge.useMeta
+import hep.dataforge.useValue
 import hep.dataforge.values.ValueType
 import hep.dataforge.values.Values
 import hep.dataforge.values.asValue
@@ -50,10 +48,17 @@ import java.util.stream.StreamSupport
 import kotlin.collections.HashMap
 import kotlin.collections.set
 
+private val filterForward = DataFilter.byMetaValue("iteration_info.reverse") {
+    !(it?.boolean ?: false)
+}
+private val filterReverse = DataFilter.byMetaValue("iteration_info.reverse") {
+    it?.boolean ?: false
+}
 
 val selectTask = task("select") {
     descriptor {
         info = "Select data from initial data pool"
+        value("forward", types = listOf(ValueType.BOOLEAN), info = "Select only forward or only backward sets")
     }
     model { meta ->
         data("*")
@@ -61,9 +66,18 @@ val selectTask = task("select") {
     }
     transform<NumassSet> { data ->
         logger.info("Starting selection from data node with size ${data.size}")
-        CustomDataFilter(meta).filter(data.checked(NumassSet::class.java)).also {
-            logger.info("Selected ${it.size} elements")
+        var res = data.checked(NumassSet::class.java).filter(CustomDataFilter(meta))
+
+        meta.useValue("forward") {
+            res = if (it.boolean) {
+                res.filter(filterForward)
+            } else {
+                res.filter(filterReverse)
+            }
         }
+
+        logger.info("Selected ${res.size} elements")
+        res
     }
 }
 
@@ -362,7 +376,15 @@ val histogramTask = task("histogram") {
         }.sumByStep(NumassAnalyzer.CHANNEL_KEY, meta.getDouble("binning", 16.0))        //apply binning
 
         // send raw table to the output
-        context.output.render(table, stage = "numass.histogram", name = name, meta = meta)
+        context.output.render(table, stage = "numass.histogram", name = name) {
+            update(meta)
+            data.toSortedMap().forEach { name, set ->
+                putNode("data", buildMeta {
+                    "name" to name
+                    set.meta.useMeta("iteration_info"){"iteration" to it}
+                })
+            }
+        }
 
         if (meta.getBoolean("plot", false)) {
             context.plotFrame("$name.plot", stage = "numass.histogram") {
@@ -379,7 +401,6 @@ val histogramTask = task("histogram") {
             }
         }
 
-
         return@join table
     }
 }
@@ -397,8 +418,8 @@ val sliceTask = task("slice") {
         val analyzer = SmartAnalyzer()
         val slices = HashMap<String, IntRange>()
         val formatBuilder = TableFormatBuilder()
-        formatBuilder.addColumn("set",ValueType.STRING)
-        formatBuilder.addColumn("time",ValueType.TIME)
+        formatBuilder.addColumn("set", ValueType.STRING)
+        formatBuilder.addColumn("time", ValueType.TIME)
         meta.getMetaList("range").forEach {
             val range = IntRange(it.getInt("from"), it.getInt("to"))
             val name = it.getString("name", range.toString())