diff --git a/build.gradle b/build.gradle
index a98f9e23..e138c1a7 100644
--- a/build.gradle
+++ b/build.gradle
@@ -21,9 +21,9 @@ allprojects{
     }
 
     dependencies{
-        compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:1.2.10"
         compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.2.10"
-        compile group: 'org.jetbrains.kotlin', name: 'kotlin-reflect', version: '1.2.10'
+        compile "org.jetbrains.kotlin:kotlin-reflect:1.2.10"
+        testCompile group: 'junit', name: 'junit', version: '4.+'
     }
 
 
diff --git a/numass-main/src/main/groovy/inr/numass/scripts/times/TestAnalyzer.groovy b/numass-main/src/main/groovy/inr/numass/scripts/times/TestAnalyzer.groovy
index b2420e68..ffd270b5 100644
--- a/numass-main/src/main/groovy/inr/numass/scripts/times/TestAnalyzer.groovy
+++ b/numass-main/src/main/groovy/inr/numass/scripts/times/TestAnalyzer.groovy
@@ -7,7 +7,7 @@ import hep.dataforge.grind.GrindShell
 import hep.dataforge.meta.Meta
 import inr.numass.NumassPlugin
 import inr.numass.actions.TimeAnalyzerAction
-import inr.numass.data.SimpleChainGenerator
+import inr.numass.data.GeneratorKt
 import inr.numass.data.api.SimpleNumassPoint
 import org.apache.commons.math3.random.JDKRandomGenerator
 
@@ -32,8 +32,8 @@ new GrindShell(ctx).eval {
 
 
     def blocks = (1..num).collect {
-        def generator = new SimpleChainGenerator(cr, new JDKRandomGenerator(), { 1000 })
-        generator.generateBlock(Instant.now().plusNanos(it * length), length) { prev, next -> next.timeOffset - prev.timeOffset > dt * 1000 }
+        def chain = GeneratorKt.buildSimpleEventChain(cr, new JDKRandomGenerator(),{10000})
+        GeneratorKt.generateBlock(Instant.now().plusNanos(it * length), length, chain)
     }
 
     def point = new SimpleNumassPoint(10000, blocks)
diff --git a/numass-main/src/main/kotlin/inr/numass/NumassPlugin.kt b/numass-main/src/main/kotlin/inr/numass/NumassPlugin.kt
index bb7b2465..f91135db 100644
--- a/numass-main/src/main/kotlin/inr/numass/NumassPlugin.kt
+++ b/numass-main/src/main/kotlin/inr/numass/NumassPlugin.kt
@@ -99,7 +99,7 @@ class NumassPlugin : BasicPlugin() {
             BivariateFunction { E: Double, U: Double ->
                 val D = E - U
                 val factor = 7.33 - E / 1000.0 / 3.0
-                return@BivariateFunction 1.0 - (3.05346E-7 * D - 5.45738E-10 * Math.pow(D, 2.0) - 6.36105E-14 * Math.pow(D, 3.0))*factor
+                return@BivariateFunction 1.0 - (3.05346E-7 * D - 5.45738E-10 * Math.pow(D, 2.0) - 6.36105E-14 * Math.pow(D, 3.0)) * factor
             }
         }
     }
@@ -281,6 +281,6 @@ class NumassPlugin : BasicPlugin() {
 fun displayJFreeChart(title: String, width: Double = 800.0, height: Double = 600.0, meta: Meta = Meta.empty()): JFreeChartFrame {
     val frame = JFreeChartFrame(meta)
     frame.configureValue("title", title)
-    FXPlugin().apply { startGlobal() }.display (PlotContainer(frame))
+    FXPlugin().apply { startGlobal() }.display(PlotContainer(frame), width, height)
     return frame
 }
diff --git a/numass-main/src/main/kotlin/inr/numass/data/ChainGenerator.kt b/numass-main/src/main/kotlin/inr/numass/data/ChainGenerator.kt
deleted file mode 100644
index 4f750f8f..00000000
--- a/numass-main/src/main/kotlin/inr/numass/data/ChainGenerator.kt
+++ /dev/null
@@ -1,114 +0,0 @@
-package inr.numass.data
-
-import inr.numass.data.api.NumassBlock
-import inr.numass.data.api.NumassEvent
-import inr.numass.data.api.SimpleBlock
-import org.apache.commons.math3.random.JDKRandomGenerator
-import org.apache.commons.math3.random.RandomGenerator
-import java.time.Duration
-import java.time.Instant
-import java.util.*
-import kotlin.collections.ArrayList
-
-interface ChainGenerator {
-
-    fun next(event: NumassEvent?): NumassEvent
-
-    fun generateBlock(start: Instant, length: Long, filter: (NumassEvent, NumassEvent) -> Boolean = { _, _ -> true }): NumassBlock {
-        val events = ArrayList<NumassEvent>()
-        var event = next(null)
-        events.add(event)
-        while (event.timeOffset < length) {
-            val nextEvent = next(event)
-            if (filter(event, nextEvent)) {
-                event = nextEvent
-                if (event.timeOffset < length) {
-                    events.add(event)
-                }
-            }
-        }
-        return SimpleBlock(start, Duration.ofNanos(length), events)
-    }
-}
-
-
-private fun RandomGenerator.nextExp(mean: Double): Double {
-    return -mean * Math.log(1 - nextDouble())
-}
-
-private fun RandomGenerator.nextDeltaTime(cr: Double): Long {
-    return (nextExp(1.0 / cr) * 1e9).toLong()
-}
-
-class SimpleChainGenerator(
-        val cr: Double,
-        private val rnd: RandomGenerator = JDKRandomGenerator(),
-        private val amp: RandomGenerator.(NumassEvent?, Long) -> Short = { _, _ -> ((nextDouble() + 2.0) * 100).toShort() }
-) : ChainGenerator {
-
-    override fun next(event: NumassEvent?): NumassEvent {
-        return if (event == null) {
-            NumassEvent(rnd.amp(null, 0), Instant.EPOCH, 0)
-        } else {
-            val deltaT = rnd.nextDeltaTime(cr)
-            NumassEvent(rnd.amp(event, deltaT), event.blockTime, event.timeOffset + deltaT)
-        }
-    }
-}
-
-class BunchGenerator(
-        private val cr: Double,
-        private val bunchRate: Double,
-        private val bunchLength: RandomGenerator.() -> Long,
-        private val rnd: RandomGenerator = JDKRandomGenerator(),
-        private val amp: RandomGenerator.(NumassEvent?, Long) -> Short = { _, _ -> ((nextDouble() + 2.0) * 100).toShort() }
-) : ChainGenerator {
-
-    private val internalGenerator = SimpleChainGenerator(cr, rnd, amp)
-
-    var bunchStart: Long = 0
-    var bunchEnd: Long = 0
-
-    override fun next(event: NumassEvent?): NumassEvent {
-        if (event?.timeOffset ?: 0 >= bunchEnd) {
-            bunchStart = bunchEnd + rnd.nextExp(bunchRate).toLong()
-            bunchEnd = bunchStart + rnd.bunchLength()
-            return NumassEvent(rnd.amp(null, 0), Instant.EPOCH, bunchStart)
-        } else {
-            return internalGenerator.next(event)
-        }
-    }
-
-    override fun generateBlock(start: Instant, length: Long, filter: (NumassEvent, NumassEvent) -> Boolean): NumassBlock {
-        bunchStart = 0
-        bunchEnd = 0
-        return super.generateBlock(start, length, filter)
-    }
-}
-
-
-class MergingGenerator(private  vararg val generators: ChainGenerator) : ChainGenerator {
-
-    private val waiting: TreeSet<Pair<ChainGenerator, NumassEvent>> = TreeSet(Comparator.comparing<Pair<ChainGenerator, NumassEvent>, Long> { it.second.timeOffset })
-
-    init {
-        generators.forEach { generator ->
-            waiting.add(Pair(generator, generator.next(null)))
-        }
-    }
-
-    override fun next(event: NumassEvent?): NumassEvent {
-        val pair = waiting.first()
-        waiting.remove(pair)
-        waiting.add(Pair(pair.first, pair.first.next(pair.second)))
-        return pair.second
-    }
-
-    override fun generateBlock(start: Instant, length: Long, filter: (NumassEvent, NumassEvent) -> Boolean): NumassBlock {
-        generators.forEach { generator ->
-            waiting.add(Pair(generator, generator.next(null)))
-        }
-        return super.generateBlock(start, length, filter)
-    }
-}
-
diff --git a/numass-main/src/main/kotlin/inr/numass/data/Generator.kt b/numass-main/src/main/kotlin/inr/numass/data/Generator.kt
new file mode 100644
index 00000000..6c71bc12
--- /dev/null
+++ b/numass-main/src/main/kotlin/inr/numass/data/Generator.kt
@@ -0,0 +1,186 @@
+package inr.numass.data
+
+import hep.dataforge.maths.chain.Chain
+import hep.dataforge.maths.chain.MarkovChain
+import hep.dataforge.maths.chain.StatefulChain
+import inr.numass.data.api.NumassBlock
+import inr.numass.data.api.NumassEvent
+import inr.numass.data.api.SimpleBlock
+import org.apache.commons.math3.random.JDKRandomGenerator
+import org.apache.commons.math3.random.RandomGenerator
+import java.time.Duration
+import java.time.Instant
+
+private fun RandomGenerator.nextExp(mean: Double): Double {
+    return -mean * Math.log(1 - nextDouble())
+}
+
+private fun RandomGenerator.nextDeltaTime(cr: Double): Long {
+    return (nextExp(1.0 / cr) * 1e9).toLong()
+}
+
+fun generateBlock(start: Instant, length: Long, chain: Chain<NumassEvent>): NumassBlock {
+    val events = chain.asSequence().takeWhile { it.timeOffset < length }.toList()
+    return SimpleBlock(start, Duration.ofNanos(length), events)
+}
+
+internal val defaultGenerator = JDKRandomGenerator()
+
+internal val defaultAmplitudeGenerator: RandomGenerator.(NumassEvent?, Long) -> Short = { _, _ -> ((nextDouble() + 2.0) * 100).toShort() }
+
+fun buildSimpleEventChain(
+        cr: Double,
+        rnd: RandomGenerator = defaultGenerator,
+        amp: RandomGenerator.(NumassEvent?, Long) -> Short = defaultAmplitudeGenerator): Chain<NumassEvent> {
+    return MarkovChain(NumassEvent(rnd.amp(null, 0), Instant.now(), 0)) { event ->
+        val deltaT = rnd.nextDeltaTime(cr)
+        NumassEvent(rnd.amp(event, deltaT), event.blockTime, event.timeOffset + deltaT)
+    }
+}
+
+private data class BunchState(var bunchStart: Long = 0, var bunchEnd: Long = 0)
+
+/**
+ * The chain of bunched events
+ * @param cr count rate of events inside bunch
+ * @param bunchRate number of bunches per second
+ * @param bunchLength the length of bunch
+ */
+fun buildBunchChain(
+        cr: Double,
+        bunchRate: Double,
+        bunchLength: Double,
+        rnd: RandomGenerator = defaultGenerator,
+        amp: RandomGenerator.(NumassEvent?, Long) -> Short = defaultAmplitudeGenerator
+): Chain<NumassEvent> {
+    return StatefulChain(
+            BunchState(0, 0),
+            NumassEvent(rnd.amp(null, 0), Instant.now(), 0)) { event ->
+        if (event.timeOffset >= bunchEnd) {
+            bunchStart = bunchEnd + (rnd.nextDeltaTime(bunchRate)).toLong()
+            bunchEnd = bunchStart + (bunchLength*1e9).toLong()
+            NumassEvent(rnd.amp(null, 0), Instant.EPOCH, bunchStart)
+        } else {
+            val deltaT = rnd.nextDeltaTime(cr)
+            NumassEvent(rnd.amp(event, deltaT), event.blockTime, event.timeOffset + deltaT)
+        }
+    }
+}
+
+private class MergingState(private val chains: List<Chain<NumassEvent>>) {
+    suspend fun poll(): NumassEvent {
+        val next = chains.minBy { it.value.timeOffset } ?: chains.first()
+        val res = next.value
+        next.next()
+        return res
+    }
+
+}
+
+fun mergeEventChains(vararg chains: Chain<NumassEvent>): Chain<NumassEvent> {
+    return StatefulChain(MergingState(listOf(*chains)),NumassEvent(0, Instant.now(), 0)){
+        poll()
+    }
+}
+//
+//
+///**
+// * @param S - intermediate state of generator
+// */
+//abstract class ChainGenerator<S> {
+//
+//    protected abstract fun next(event: NumassEvent?, state: S = buildState()): NumassEvent
+//
+//    fun buildSequence(): Sequence<NumassEvent> {
+//        val state = buildState()
+//        return generateSequence(seed = null) { event: NumassEvent? ->
+//            next(event, state)
+//        }
+//    }
+//
+//    protected abstract fun buildState(): S
+//
+//    fun generateBlock(start: Instant, length: Long): NumassBlock {
+//        val events = buildSequence().takeWhile { it.timeOffset < length }.toList()
+//        return SimpleBlock(start, Duration.ofNanos(length), events)
+//    }
+//}
+//
+//
+//class SimpleChainGenerator(
+//        val cr: Double,
+//        private val rnd: RandomGenerator = JDKRandomGenerator(),
+//        private val amp: RandomGenerator.(NumassEvent?, Long) -> Short = { _, _ -> ((nextDouble() + 2.0) * 100).toShort() }
+//) : ChainGenerator<Unit>() {
+//
+//    override fun buildState() {
+//        return Unit
+//    }
+//
+//    override fun next(event: NumassEvent?, state: Unit): NumassEvent {
+//        return if (event == null) {
+//            NumassEvent(rnd.amp(null, 0), Instant.EPOCH, 0)
+//        } else {
+//            val deltaT = rnd.nextDeltaTime(cr)
+//            NumassEvent(rnd.amp(event, deltaT), event.blockTime, event.timeOffset + deltaT)
+//        }
+//    }
+//
+//    fun next(event: NumassEvent?): NumassEvent {
+//        return next(event, Unit)
+//    }
+//}
+//
+//class BunchGenerator(
+//        private val cr: Double,
+//        private val bunchRate: Double,
+//        private val bunchLength: RandomGenerator.() -> Long,
+//        private val rnd: RandomGenerator = JDKRandomGenerator(),
+//        private val amp: RandomGenerator.(NumassEvent?, Long) -> Short = { _, _ -> ((nextDouble() + 2.0) * 100).toShort() }
+//) : ChainGenerator<BunchGenerator.BunchState>() {
+//
+//    private val internalGenerator = SimpleChainGenerator(cr, rnd, amp)
+//
+//    class BunchState(var bunchStart: Long = 0, var bunchEnd: Long = 0)
+//
+//    override fun next(event: NumassEvent?, state: BunchState): NumassEvent {
+//        if (event?.timeOffset ?: 0 >= state.bunchEnd) {
+//            state.bunchStart = state.bunchEnd + (rnd.nextExp(bunchRate) * 1e9).toLong()
+//            state.bunchEnd = state.bunchStart + rnd.bunchLength()
+//            return NumassEvent(rnd.amp(null, 0), Instant.EPOCH, state.bunchStart)
+//        } else {
+//            return internalGenerator.next(event)
+//        }
+//    }
+//
+//    override fun buildState(): BunchState {
+//        return BunchState(0, 0)
+//    }
+//}
+//
+//
+//class MergingGenerator(private vararg val generators: ChainGenerator<*>) : ChainGenerator<MergingGenerator.MergingState>() {
+//
+//    inner class MergingState {
+//        val queue: PriorityQueue<Pair<Sequence<NumassEvent>, NumassEvent>> =
+//                PriorityQueue(Comparator.comparing<Pair<Sequence<NumassEvent>, NumassEvent>, Long> { it.second.timeOffset })
+//
+//        init {
+//            generators.forEach { generator ->
+//                val sequence = generator.buildSequence()
+//                queue.add(Pair(sequence, sequence.iterator().next()))
+//            }
+//        }
+//    }
+//
+//    override fun next(event: NumassEvent?, state: MergingState): NumassEvent {
+//        val pair = state.queue.poll()
+//        state.queue.add(Pair(pair.first, pair.first.iterator().next()))
+//        return pair.second
+//    }
+//
+//    override fun buildState(): MergingState {
+//        return MergingState()
+//    }
+//}
+//
diff --git a/numass-main/src/main/kotlin/inr/numass/scripts/Bunches.kt b/numass-main/src/main/kotlin/inr/numass/scripts/Bunches.kt
index abd842e1..28f5f374 100644
--- a/numass-main/src/main/kotlin/inr/numass/scripts/Bunches.kt
+++ b/numass-main/src/main/kotlin/inr/numass/scripts/Bunches.kt
@@ -1,33 +1,27 @@
 package inr.numass.scripts
 
-import hep.dataforge.fx.plots.PlotManager
-import hep.dataforge.kodex.buildContext
 import hep.dataforge.kodex.buildMeta
-import inr.numass.NumassPlugin
-import inr.numass.data.BunchGenerator
-import inr.numass.data.MergingGenerator
-import inr.numass.data.SimpleChainGenerator
 import inr.numass.data.analyzers.NumassAnalyzer
 import inr.numass.data.analyzers.SmartAnalyzer
 import inr.numass.data.api.SimpleNumassPoint
+import inr.numass.data.buildBunchChain
+import inr.numass.data.buildSimpleEventChain
+import inr.numass.data.generateBlock
+import inr.numass.data.mergeEventChains
 import java.time.Instant
 
 fun main(args: Array<String>) {
 
-    val context = buildContext("NUMASS", NumassPlugin::class.java, PlotManager::class.java)
-
     val cr = 10.0
-    val length = 30e9.toLong()
-    val num = 50;
-    val dt = 6.5
-
-    val regularGenerator = SimpleChainGenerator(cr)
-    val bunchGenerator = BunchGenerator(40.0, 0.1, { 2e9.toLong() })
-
-    val generator = MergingGenerator(regularGenerator, bunchGenerator)
+    val length = 1e12.toLong()
+    val num = 20;
 
     val blocks = (1..num).map {
-        generator.generateBlock(Instant.now().plusNanos(it * length), length)
+        val regularChain = buildSimpleEventChain(cr)
+        val bunchChain = buildBunchChain(20.0, 0.01, 5.0)
+
+        val generator = mergeEventChains(regularChain, bunchChain)
+        generateBlock(Instant.now().plusNanos(it * length), length, generator)
     }
 
     val point = SimpleNumassPoint(10000.0, blocks)
@@ -36,11 +30,11 @@ fun main(args: Array<String>) {
         "t0.crFraction" to 0.1
     }
 
-    println("actual count rate: ${point.events.count() / point.length.seconds}")
+    println("actual count rate: ${point.events.count().toDouble() / point.length.seconds}")
 
-    val res = SmartAnalyzer().analyze(point,meta)
+    val res = SmartAnalyzer().analyze(point, meta)
             .getDouble(NumassAnalyzer.COUNT_RATE_KEY)
 
-    println("estimated count rate: ${res}")
+    println("estimated count rate: $res")
 
 }
\ No newline at end of file
diff --git a/numass-viewer/src/main/kotlin/inr/numass/viewer/AmplitudeView.kt b/numass-viewer/src/main/kotlin/inr/numass/viewer/AmplitudeView.kt
index acb0662f..25c051ea 100644
--- a/numass-viewer/src/main/kotlin/inr/numass/viewer/AmplitudeView.kt
+++ b/numass-viewer/src/main/kotlin/inr/numass/viewer/AmplitudeView.kt
@@ -3,6 +3,7 @@ package inr.numass.viewer
 import hep.dataforge.fx.dfIcon
 import hep.dataforge.fx.plots.PlotContainer
 import hep.dataforge.fx.runGoal
+import hep.dataforge.fx.ui
 import hep.dataforge.goals.Goal
 import hep.dataforge.kodex.configure
 import hep.dataforge.meta.Meta
@@ -13,6 +14,7 @@ import hep.dataforge.tables.Adapters
 import hep.dataforge.tables.Table
 import inr.numass.data.analyzers.NumassAnalyzer
 import inr.numass.data.analyzers.SimpleAnalyzer
+import inr.numass.data.analyzers.spectrumWithBinning
 import inr.numass.data.api.NumassPoint
 import javafx.beans.Observable
 import javafx.beans.binding.DoubleBinding
@@ -131,7 +133,7 @@ class AmplitudeView(
                     DataPlot.plot(
                             key,
                             Adapters.buildXYAdapter(NumassAnalyzer.CHANNEL_KEY, valueAxis),
-                            NumassAnalyzer.spectrumWithBinning(getSpectrum(point), binning)
+                            spectrumWithBinning(getSpectrum(point), binning)
                     ).configure {
                         "connectionType" to "step"
                         "thickness" to 2
@@ -140,7 +142,7 @@ class AmplitudeView(
                         "showErrors" to false
                         "JFreeChart.cache" to true
                     }
-                }.ui { plot ->
+                } ui { plot ->
                     frame.add(plot)
                     progress.invalidate()
                 }
diff --git a/numass-viewer/src/main/kotlin/inr/numass/viewer/SpectrumView.kt b/numass-viewer/src/main/kotlin/inr/numass/viewer/SpectrumView.kt
index 1d9e0bd9..2e955e25 100644
--- a/numass-viewer/src/main/kotlin/inr/numass/viewer/SpectrumView.kt
+++ b/numass-viewer/src/main/kotlin/inr/numass/viewer/SpectrumView.kt
@@ -13,6 +13,7 @@ import hep.dataforge.tables.Adapters
 import hep.dataforge.tables.Table
 import inr.numass.data.analyzers.NumassAnalyzer
 import inr.numass.data.analyzers.SimpleAnalyzer
+import inr.numass.data.analyzers.countInWindow
 import inr.numass.data.api.NumassPoint
 import inr.numass.data.api.NumassSet
 import javafx.beans.property.SimpleIntegerProperty
@@ -172,7 +173,7 @@ class SpectrumView(
 
             runGoal("spectrumData[$name]") {
                 set.points.map { point ->
-                    val count = NumassAnalyzer.countInWindow(getSpectrum(point), loChannel.toShort(), upChannel.toShort());
+                    val count = countInWindow(getSpectrum(point), loChannel.toShort(), upChannel.toShort());
                     val seconds = point.length.toMillis() / 1000.0;
                     runLater {
                         container.progress = progress.incrementAndGet().toDouble() / totalProgress
diff --git a/numass-viewer/src/main/kotlin/inr/numass/viewer/test/ComponentTest.kt b/numass-viewer/src/main/kotlin/inr/numass/viewer/test/ComponentTest.kt
index 680232ec..8a712488 100644
--- a/numass-viewer/src/main/kotlin/inr/numass/viewer/test/ComponentTest.kt
+++ b/numass-viewer/src/main/kotlin/inr/numass/viewer/test/ComponentTest.kt
@@ -12,7 +12,6 @@ import inr.numass.viewer.SpectrumView
 import javafx.application.Application
 import javafx.scene.image.ImageView
 import tornadofx.*
-import java.io.File
 import java.util.concurrent.ConcurrentHashMap
 import java.util.stream.Collectors
 
@@ -36,8 +35,7 @@ class ViewerComponentsTest : View(title = "Numass viewer test", icon = ImageView
             button("Click me!") {
                 action {
                     runAsync {
-                        val rootDir = File("D:\\Work\\Numass\\data\\2017_05\\Fill_2")
-                        val set: NumassSet = NumassStorageFactory.buildLocal(global, rootDir, true, true)
+                        val set: NumassSet = NumassStorageFactory.buildLocal(global, "D:\\Work\\Numass\\data\\2017_05\\Fill_2", true, true)
                                 .provide("loader::set_2", NumassSet::class.java)
                                 .orElseThrow { RuntimeException("err") }
                         update(set);