diff --git a/system/dataset.py b/system/dataset.py
index 29f6bdd..2362d9b 100644
--- a/system/dataset.py
+++ b/system/dataset.py
@@ -160,10 +160,6 @@ class Dataset:
         """Returns dataset name"""
         return self._name
 
-    def get_matrix(self):
-        """Returns internal numeric matrix for dataset."""
-        return self._array
-
     def get_all_dims(self):
         """Returns all dimensions in project"""
         return self._all_dims
diff --git a/system/plots.py b/system/plots.py
index 3c4d6c0..212ac15 100644
--- a/system/plots.py
+++ b/system/plots.py
@@ -386,7 +386,7 @@ class LinePlot(Plot):
         import rpy
         silent_eval = rpy.with_mode(rpy.NO_CONVERSION, rpy.r)
 
-        rpy.with_mode(rpy.NO_CONVERSION, rpy.r.assign)("m", dataset.get_matrix())        
+        rpy.with_mode(rpy.NO_CONVERSION, rpy.r.assign)("m", dataset.asarray())        
         ymin, ymax = rpy.r("range(m)*1.1")
         self._ymin, self._ymax = ymin, ymax
         silent_eval("res <- apply(m, 2, density, from=%s, to=%s)" % (ymin, ymax))
@@ -420,7 +420,7 @@ class LinePlot(Plot):
             ids = selection[dim_2] # current identifiers
             index = [ind for id,ind in self._dataset[dim_2].items() if id in ids] #conversion to index
             for i in index:
-                line = self._dataset.get_matrix()[i]
+                line = self._dataset.asarray()[i]
                 self.ax.plot(range(1, len(line)+1), line)
             
         self.ax.set_xlim((0.5, cols+0.5))
diff --git a/workflows/affy_workflow.py b/workflows/affy_workflow.py
index 602e109..5a4e756 100644
--- a/workflows/affy_workflow.py
+++ b/workflows/affy_workflow.py
@@ -203,7 +203,7 @@ class PCAFunction(workflow.Function):
         dim_2, dim_1 = data.get_dim_names()
     
         silent_eval = rpy.with_mode(rpy.NO_CONVERSION, rpy.r)
-        rpy.with_mode(rpy.NO_CONVERSION, rpy.r.assign)("m", data.get_matrix())
+        rpy.with_mode(rpy.NO_CONVERSION, rpy.r.assign)("m", data.asarray())
         silent_eval("t = prcomp(t(m))")
 
         # we make a unique name for component dimension
diff --git a/workflows/go_workflow.py b/workflows/go_workflow.py
index 4a893c6..3dd9f73 100644
--- a/workflows/go_workflow.py
+++ b/workflows/go_workflow.py
@@ -236,7 +236,7 @@ class PCAFunction(workflow.Function):
         
     
         silent_eval = rpy.with_mode(rpy.NO_CONVERSION, rpy.r)
-        rpy.with_mode(rpy.NO_CONVERSION, rpy.r.assign)("m", data.get_matrix())
+        rpy.with_mode(rpy.NO_CONVERSION, rpy.r.assign)("m", data.asarray())
         silent_eval("t = prcomp(t(m))")
 
         T_ids = map(str, range(1, rpy.r("dim(t$x)")[1]+1))