From 189d2ee0f9fc1153afa70e1d367a21cdfc8a5c1f Mon Sep 17 00:00:00 2001
From: Craig Warren <craig_warren@me.com>
Date: Tue, 12 Jan 2016 17:45:12 +0000
Subject: [PATCH] Made rounding function more generic.

---
 gprMax/input_cmds_singleuse.py |  5 +++--
 gprMax/utilities.py            | 33 +++++++++++++--------------------
 2 files changed, 16 insertions(+), 22 deletions(-)

diff --git a/gprMax/input_cmds_singleuse.py b/gprMax/input_cmds_singleuse.py
index ecda5503..ab72eb73 100644
--- a/gprMax/input_cmds_singleuse.py
+++ b/gprMax/input_cmds_singleuse.py
@@ -17,13 +17,14 @@
 # along with gprMax.  If not, see <http://www.gnu.org/licenses/>.
 
 import os, sys
+import decimal as d
 import numpy as np
 from psutil import virtual_memory
 
 from gprMax.constants import c, floattype
 from gprMax.exceptions import CmdInputError
 from gprMax.pml import PML, CFS
-from gprMax.utilities import roundvalue, rounddownmax, human_size
+from gprMax.utilities import roundvalue, human_size
 from gprMax.waveforms import Waveform
 
 
@@ -146,7 +147,7 @@ def process_singlecmds(singlecmds, multicmds, G):
         G.dt = 1 / (c * np.sqrt((1 / G.dx) * (1 / G.dx) + (1 / G.dy) * (1 / G.dy) + (1 / G.dz) * (1 / G.dz)))
 
     # Round down time step to nearest float with precision one less than hardware maximum. Avoids inadvertently exceeding the CFL due to binary representation of floating point number.
-    G.dt = rounddownmax(G.dt)
+    G.dt = roundvalue(G.dt, decimalplaces=d.getcontext().prec - 1)
 
     if G.messages:
         print('Time step: {:.3e} secs'.format(G.dt))
diff --git a/gprMax/utilities.py b/gprMax/utilities.py
index 56319856..c0031bd2 100644
--- a/gprMax/utilities.py
+++ b/gprMax/utilities.py
@@ -79,34 +79,27 @@ def update_progress(progress):
     sys.stdout.flush()
 
 
-def roundvalue(value):
-    """Rounds to nearest integer (half values are rounded downwards).
+def roundvalue(value, decimalplaces=0):
+    """Rounding function.
         
     Args:
         value (float): Number to round.
+        decimalplaces (int): Number of decimal places of float to represent rounded value.
         
     Returns:
-        Rounded value (int).
+        rounded (int/float): Rounded value.
     """
     
-    return int(d.Decimal(value).quantize(d.Decimal('1'),rounding=d.ROUND_HALF_DOWN))
-
-
-def rounddownmax(value):
-    """Rounds down to nearest float with precision one less than hardware maximum.
-        
-    Args:
-        value (float): Number to round.
-        
-    Returns:
-        Rounded value (float).
-    """
+    # Rounds to nearest integer (half values are rounded downwards)
+    if decimalplaces == 0:
+        rounded = int(d.Decimal(value).quantize(d.Decimal('1'),rounding=d.ROUND_HALF_DOWN))
     
-    decimalplaces = d.getcontext().prec
-    decimalplaces -= 1
-    precision = '1.{places}'.format(places='0' * decimalplaces)
-    
-    return float(d.Decimal(value).quantize(d.Decimal(precision),rounding=d.ROUND_FLOOR))
+    # Rounds down to nearest float represented by number of decimal places
+    else:
+        precision = '1.{places}'.format(places='0' * decimalplaces)
+        rounded = float(d.Decimal(value).quantize(d.Decimal(precision),rounding=d.ROUND_FLOOR))
+
+    return rounded
 
 
 def human_size(size, a_kilobyte_is_1024_bytes=True):