r23226 - /branches/disp_speed/lib/dispersion/lm63.py -- May 19, 2014 - 03:20

Author: tlinnet
Date: Mon May 19 03:20:51 2014
New Revision: 23226

URL: http://svn.gna.org/viewcvs/relax?rev=23226&view=rev
Log:
Speed-up of model LM63.

task #7793: (https://gna.org/task/?7793) Speed-up of dispersion models.

Change in systemtest was:
test_hansen_cpmg_data_auto_analysis
13.731s -> 9.971s

test_hansen_cpmg_data_auto_analysis_r2eff
13.370s -> 9.510s

test_hansen_cpmg_data_to_lm63
3.254s -> 2.080s

Modified:
    branches/disp_speed/lib/dispersion/lm63.py

Modified: branches/disp_speed/lib/dispersion/lm63.py
URL: 
http://svn.gna.org/viewcvs/relax/branches/disp_speed/lib/dispersion/lm63.py?rev=23226&r1=23225&r2=23226&view=diff
==============================================================================
--- branches/disp_speed/lib/dispersion/lm63.py  (original)
+++ branches/disp_speed/lib/dispersion/lm63.py  Mon May 19 03:20:51 2014
@@ -64,7 +64,7 @@
 """
 
 # Python module imports.
-from math import tanh
+from numpy import isfinite, sum, tanh
 
 
 def r2eff_LM63(r20=None, phi_ex=None, kex=None, cpmg_frqs=None, 
back_calc=None, num_points=None):
@@ -91,16 +91,14 @@
     rex = phi_ex / kex
     kex_4 = 4.0 / kex
 
-    # Loop over the time points, back calculating the R2eff values.
+    # Calculate R2eff.
+    R2eff = r20 + rex * (1.0 - kex_4 * cpmg_frqs * tanh(kex / (4.0 * 
cpmg_frqs)))
+
+    # Catch errors, taking a sum over array is the fastest way to check for
+    # +/- inf (infinity) and nan (not a number).
+    if not isfinite(sum(R2eff)):
+        R2eff = array([1e100]*num_points)
+
+    # Parse back the value to update the back_calc class object.
     for i in range(num_points):
-        # Catch zeros.
-        if phi_ex == 0.0:
-            back_calc[i] = r20
-
-        # Avoid divide by zero.
-        elif kex == 0.0:
-            back_calc[i] = 1e100
-
-        # The full formula.
-        else:
-            back_calc[i] = r20 + rex * (1.0 - kex_4 * cpmg_frqs[i] * 
tanh(kex / (4.0 * cpmg_frqs[i])))
+        back_calc[i] = R2eff[i]