diff --git a/.gitignore b/.gitignore
index 0205e3c..d86b5b3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,4 +3,7 @@ build/*
 *.o
 test_priv
 test_priv/*
-**/__pycache__
\ No newline at end of file
+**/__pycache__
+coverage.xml
+.coverage
+htmlcov
diff --git a/.vscode/launch.json b/.vscode/launch.json
new file mode 100644
index 0000000..b6448d6
--- /dev/null
+++ b/.vscode/launch.json
@@ -0,0 +1,15 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Python: Debug tests",
+            "type": "python",
+            "request": "launch",
+            "program": "nose2 -v",
+            "console": "integratedTerminal"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/repgen/data/value.py b/repgen/data/value.py
index eebf844..3004f20 100644
--- a/repgen/data/value.py
+++ b/repgen/data/value.py
@@ -1,8 +1,10 @@
 import pytz,datetime,sys
-from inspect import isfunction
+from inspect import isclass, isfunction
+import operator
 # types
 string_types = ("".__class__,u"".__class__)
 number_types = (int,float,complex)
+array_type = ([].__class__,().__class__)
 
 class Value:
 	shared = {
@@ -67,6 +69,9 @@ def __init__( self, *args, **kwargs ):
 		elif self.dbtype.upper() == "GENTS":
 			current_t = self.start
 			end_t = self.end
+			if isinstance(self.value, array_type):
+				self.values = self.value
+				return
 			while current_t <= end_t:
 				if isinstance(self.value, number_types):
 					self.values.append( ( current_t.astimezone(self.tz),self.value,0 ) )
@@ -74,7 +79,7 @@ def __init__( self, *args, **kwargs ):
 					self.value = self.value.value 
 					self.values.append( ( current_t.astimezone(self.tz),self.value,0 ) )
 				elif isfunction(self.value):
-					self.values.append( ( current_t.astimezone(self.tz),self.value(),0 ) )
+					self.values.append( ( current_t.astimezone(self.tz),self.value(),0 ) )				
 					
 				current_t = current_t + self.interval
 			
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..555c541
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1 @@
+from . dataset import Dataset,Result
\ No newline at end of file
diff --git a/tests/dataset.py b/tests/dataset.py
new file mode 100644
index 0000000..03bf812
--- /dev/null
+++ b/tests/dataset.py
@@ -0,0 +1,34 @@
+import datetime
+# simple timeseries data set to load in from disk
+class Dataset:
+    
+
+    def __init__(self, set_name):
+        self.values = []
+        self.start = None
+        self.end = None
+        self.index = 0
+        with open("tests/datasets/Set_%s.csv"%set_name,"r") as results:
+            for line in results.readlines():                
+                date,val,qual = line.strip().split(",")
+                _d = datetime.datetime.fromisoformat(date)
+                if self.start == None:
+                    self.start = _d
+                self.values.append( (_d,float(val),int(qual)))
+                self.end = _d
+
+    def values_all(self):
+        self.index = self.index + 1
+        return self.values[self.index-1]
+            
+    
+    def values_only(self):
+        self.index = self.index + 1
+        return self.values[self.index-1][1]
+
+class Result:    
+    def __init__(self, result_set_name):
+        self.values = []
+        with open("tests/datasets/Result_%s.res" %result_set_name,"r") as results:
+            for value in results.readlines():
+                self.values.append( float(value) )
diff --git a/tests/datasets/Result_SimpleStageTimes2.res b/tests/datasets/Result_SimpleStageTimes2.res
new file mode 100644
index 0000000..cecf967
--- /dev/null
+++ b/tests/datasets/Result_SimpleStageTimes2.res
@@ -0,0 +1,8 @@
+2
+4
+6
+8
+10
+12
+14
+16
\ No newline at end of file
diff --git a/tests/datasets/Set_SimpleStage.csv b/tests/datasets/Set_SimpleStage.csv
new file mode 100644
index 0000000..d1b07be
--- /dev/null
+++ b/tests/datasets/Set_SimpleStage.csv
@@ -0,0 +1,8 @@
+2021-01-01T00:00:00+00:00,1,0
+2021-01-01T00:15:00+00:00,2,0
+2021-01-01T00:30:00+00:00,3,0
+2021-01-01T00:45:00+00:00,4,0
+2021-01-01T01:00:00+00:00,5,0
+2021-01-01T01:15:00+00:00,6,0
+2021-01-01T01:30:00+00:00,7,0
+2021-01-01T01:45:00+00:00,8,0
\ No newline at end of file
diff --git a/tests/test_value.py b/tests/test_value.py
index 80615ed..8172560 100644
--- a/tests/test_value.py
+++ b/tests/test_value.py
@@ -4,7 +4,7 @@
 import datetime
 sys.path.append("../")
 
-
+from . dataset import Dataset,Result
 from repgen.data import Value
 from repgen.util import TZ
 
@@ -34,3 +34,33 @@ def data():
     assert v.values[3][1] == 3
     assert v.values[4][1] == 4
     assert v.values[8][1] == 8
+
+
+def test_simple_sum():
+    v1 = Value(1)
+    v2 = Value(2)
+    v3 = v1+v2
+    assert v3.value == 3
+
+def test_multiply():
+    stage = Dataset("SimpleStage")    
+    assert stage.start != None
+    assert stage.end != None
+    assert len(stage.values) > 0
+
+    def data():
+        data.index += 1
+        return stage.values[data.index-1][1]
+    data.index = 0
+    data.stage = stage
+
+    v1 = Value(dbtype="GENTS", value = data, tz="UTC",start=stage.start,end=stage.end, interval = datetime.timedelta(minutes=15), picture="%0.02f")
+    assert len(v1.values) > 0
+    
+    v2 = v1*2
+
+    result = Result("SimpleStageTimes2")
+    assert len(v2.values) > 0
+    
+    for i in range(len(v2.values)):        
+        assert int(v2.values[i][1]) == int(result.values[i])
\ No newline at end of file
diff --git a/unittest.cfg b/unittest.cfg
new file mode 100644
index 0000000..51ed898
--- /dev/null
+++ b/unittest.cfg
@@ -0,0 +1,3 @@
+[coverage]
+always-on = True
+coverage = repgen