diff --git a/QtPyLoT.py b/QtPyLoT.py
index a2476e9c..08a67127 100755
--- a/QtPyLoT.py
+++ b/QtPyLoT.py
@@ -43,6 +43,7 @@ from obspy import UTCDateTime
 from pylot.core.read.data import Data
 from pylot.core.read.inputs import FilterOptions, AutoPickParameter
 from pylot.core.pick.autopick import autopickevent
+from pylot.core.read.io import picks_from_evt
 from pylot.core.loc.nll import locate as locateNll
 from pylot.core.util.defaults import FILTERDEFAULTS, COMPNAME_MAP
 from pylot.core.util.errors import FormatError, DatastructureError, \
@@ -734,34 +735,7 @@ class MainWindow(QMainWindow):
         return rval
 
     def updatePicks(self, type='manual'):
-        evt = self.getData().getEvtData()
-        picks = {}
-        for pick in evt.picks:
-            phase = {}
-            station = pick.waveform_id.station_code
-            try:
-                onsets = picks[station]
-            except KeyError as e:
-                print(e)
-                onsets = {}
-            mpp = pick.time
-            lpp = mpp + pick.time_errors.upper_uncertainty
-            epp = mpp - pick.time_errors.lower_uncertainty
-            spe = pick.time_errors.uncertainty
-            phase['mpp'] = mpp
-            phase['epp'] = epp
-            phase['lpp'] = lpp
-            phase['spe'] = spe
-            try:
-                picker = str(pick.method_id)
-                if picker.startswith('smi:local/'):
-                    picker = picker.split('smi:local/')[1]
-                phase['picker'] = picker
-            except IndexError:
-                pass
-
-            onsets[pick.phase_hint] = phase.copy()
-            picks[station] = onsets.copy()
+        picks = picks_from_evt(evt=self.getData().getEvtData())
         if type == 'manual':
             self.picks.update(picks)
         elif type == 'auto':
diff --git a/pylot/core/pick/compare.py b/pylot/core/pick/compare.py
index 0f51b97b..c0be3fed 100644
--- a/pylot/core/pick/compare.py
+++ b/pylot/core/pick/compare.py
@@ -1,8 +1,31 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+from obspy import read_events
+
+from pylot.core.read.io import picks_from_evt
 from pylot.core.util.pdf import ProbabilityDensityFunction
 from pylot.core.util.version import get_git_version as _getVersionString
 
 __version__ = _getVersionString()
 __author__ = 'sebastianw'
+
+
+def readData(fn):
+    """
+    Reads pick data from QuakeML files named FN and returns a dictionary
+    containing a ProbabilityDensityFunction object for each pick.
+    :param fn: name of the QuakeML file which contains the picks
+    :type fn: str
+    :return: a dictionary containing the picks represented as pdfs
+    """
+    pdf_picks = picks_from_evt(read_events(fn)[0])
+
+    for station, phases in pdf_picks.items():
+        for phase, values in phases.items():
+            phases[phase] = ProbabilityDensityFunction.fromPick(values['epp'],
+                                                                values['mpp'],
+                                                                values['lpp'],
+                                                                type='exp')
+
+    return pdf_picks
diff --git a/pylot/core/read/io.py b/pylot/core/read/io.py
index cd9b2149..b499d911 100644
--- a/pylot/core/read/io.py
+++ b/pylot/core/read/io.py
@@ -134,3 +134,40 @@ def readPILOTEvent(phasfn=None, locfn=None, authority_id=None, **kwargs):
     except AttributeError as e:
         raise AttributeError('{0} - Matlab LOC files {1} and {2} contains \
                               insufficient data!'.format(e, phasfn, locfn))
+
+def picks_from_evt(evt):
+    '''
+    Takes an Event object and return the pick dictionary commonly used within
+    PyLoT
+    :param evt: Event object contain all available information
+    :type evt: `~obspy.core.event.Event`
+    :return: pick dictionary
+    '''
+    picks = {}
+    for pick in evt.picks:
+        phase = {}
+        station = pick.waveform_id.station_code
+        try:
+            onsets = picks[station]
+        except KeyError as e:
+            print(e)
+            onsets = {}
+        mpp = pick.time
+        lpp = mpp + pick.time_errors.upper_uncertainty
+        epp = mpp - pick.time_errors.lower_uncertainty
+        spe = pick.time_errors.uncertainty
+        phase['mpp'] = mpp
+        phase['epp'] = epp
+        phase['lpp'] = lpp
+        phase['spe'] = spe
+        try:
+            picker = str(pick.method_id)
+            if picker.startswith('smi:local/'):
+                picker = picker.split('smi:local/')[1]
+            phase['picker'] = picker
+        except IndexError:
+            pass
+
+        onsets[pick.phase_hint] = phase.copy()
+        picks[station] = onsets.copy()
+    return picks
\ No newline at end of file
diff --git a/pylot/core/util/pdf.py b/pylot/core/util/pdf.py
index 556f36ca..89481ce6 100644
--- a/pylot/core/util/pdf.py
+++ b/pylot/core/util/pdf.py
@@ -180,7 +180,8 @@ class ProbabilityDensityFunction(object):
         self._x = np.array(x)
 
     @classmethod
-    def fromPick(self, incr, lbound, barycentre, rbound, decfact=0.01, type='gauss'):
+    def fromPick(self, lbound, barycentre, rbound, incr=0.005, decfact=0.01,
+                 type='gauss'):
         '''
         Initialize a new ProbabilityDensityFunction object.
         Takes incr, lbound, barycentre and rbound to derive x0 and the number
@@ -199,7 +200,10 @@ class ProbabilityDensityFunction(object):
         try:
             midpoint = (rbound + lbound) / 2
         except TypeError:
-            midpoint = (rbound + float(lbound)) / 2
+            try:
+                midpoint = (rbound + float(lbound)) / 2
+            except TypeError:
+                midpoint = float(rbound + float(lbound)) / 2
 
         # find x0 on a grid point and sufficient npts
         n = int(np.ceil((barycentre - midpoint) / incr))