diff --git a/post-process.py b/post-process.py
index 746db3503a9c1f6db7196595c7b4796a99100379..ce70ff1b7ad9ab8f1c4c6e21c15a6e55f655b13c 100755
--- a/post-process.py
+++ b/post-process.py
@@ -1,9 +1,12 @@
 #!/usr/bin/env python
 """
 Usage:
-    post-process.py [options] output-log
+    post-process.py [options] output-log matched-log
 
-Match the sends and recvs across the ranks and output a unified log.
+Match the sends and recvs across the ranks so that the timings for message
+completion can be checked. This is written to the file matched_log.  Also
+produces simple report of some interesting values and produces plots comparing
+various timings.
 
 This file is part of SWIFT.
 
@@ -24,6 +27,10 @@ You should have received a copy of the GNU Lesser General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 """
 
+import matplotlib
+matplotlib.use("Agg")
+import numpy
+import pylab as pl
 import sys
 import argparse
 
@@ -33,6 +40,9 @@ parser = argparse.ArgumentParser(description="Match MPI reports")
 parser.add_argument(
     "input",
     help="Output log from simulator")
+parser.add_argument(
+    "output",
+    help="Matched entries from the input data")
 parser.add_argument(
     "-v",
     "--verbose",
@@ -43,6 +53,7 @@ parser.add_argument(
 )
 args = parser.parse_args()
 infile = args.input
+outfile = args.output
 
 #  Indices for words in a line.
 logticcol=0
@@ -63,8 +74,14 @@ mincol=14
 maxcol=15
 
 #  Keyed lines.
-sends = {}
-recvs = {}
+keysends = {}
+keyrecvs = {}
+
+#  Indexed lines.
+sends = []
+recvs = []
+nsends = 0
+nrecvs = 0
 
 #  Gather keys from the input log. We created dicts with matchable keys
 #  for when sends start and recvs end. Other pairings are possible...
@@ -80,10 +97,12 @@ with open(infile, "r") as fp:
                   words[isubtypecol] + "/" + \
                   words[tagcol] + "/" + \
                   words[sizecol]
-            if not key in sends:
-                sends[key] = [line[:-1]]
+            if not key in keysends:
+                keysends[key] = [nsends]
             else:
-                sends[key].append(line[:-1])
+                keysends[key].append(nsends)
+            sends.append(words)
+            nsends = nsends + 1
 
         elif words[itypecol] == "23":
             key = words[rankcol] + "/" + \
@@ -91,21 +110,26 @@ with open(infile, "r") as fp:
                   words[isubtypecol] + "/" + \
                   words[tagcol] + "/" + \
                   words[sizecol]
-            if not key in recvs:
-                recvs[key] = [line[:-1]]
+            if not key in keyrecvs:
+                keyrecvs[key] = [nrecvs]
             else:
-                recvs[key].append(line[:-1])
+                keyrecvs[key].append(nrecvs)
+            recvs.append(words)
+            nrecvs = nrecvs + 1
 
 #  Now output. Note we could have unmatched recv keys, we don't check for that.
-print "# send_logticin send_logtic send_injtic send_endtic send_dtic send_step send_rank send_otherrank send_itype send_isubtype send_tag send_size send_nr_tests send_tsum send_tmin send_tmax recv_logticin recv_logtic recv_injtic recv_endtic recv_dtic recv_step recv_rank recv_otherrank recv_itype recv_isubtype recv_tag recv_size recv_nr_tests recv_tsum recv_tmin recv_tmax"
-for key in sends:
-    if key in recvs:
-        if len(sends[key]) == 1 and len(recvs[key]) == 1:
-            print sends[key][0], recvs[key][0]
+with open(outfile, "w") as fp:
+    fp.write("# send_logticin send_logtic send_injtic send_endtic send_dtic send_step send_rank send_otherrank send_itype send_isubtype send_tag send_size send_nr_tests send_tsum send_tmin send_tmax recv_logticin recv_logtic recv_injtic recv_endtic recv_dtic recv_step recv_rank recv_otherrank recv_itype recv_isubtype recv_tag recv_size recv_nr_tests recv_tsum recv_tmin recv_tmax\n")
+    for key in keysends:
+        if key in keyrecvs:
+            if len(keysends[key]) == 1 and len(keyrecvs[key]) == 1:
+                isend = keysends[key][0]
+                irecv = keyrecvs[key][0]
+                fp.write(" ".join(sends[isend]) + " " + " ".join(recvs[irecv]) + "\n")
+            else:
+                print "# ERROR: found ", len(keysends[key]), "/", len(keyrecvs[key]), " matches for key: ", key, " should be 1/1"
         else:
-            print "# ERROR: found ", len(sends[key]), "/", len(recvs[key]), " matches for key: ", key, " should be 1/1"
-    else:
-        print "# ERROR: missing recv key: ", key
+            print "# ERROR: missing recv key: ", key
 
 
 sys.exit(0)