r23295 - /branches/disp_speed/lib/dispersion/cr72.py -- May 21, 2014 - 13:02

Author: tlinnet
Date: Wed May 21 13:02:55 2014
New Revision: 23295

URL: http://svn.gna.org/viewcvs/relax?rev=23295&view=rev
Log:
Align math-domain catching for model CR72 with trunk implementation.

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

This is to implement catching of math domain errors, before they occur.

The catching of errors have to be more careful.

Modified:
    branches/disp_speed/lib/dispersion/cr72.py

Modified: branches/disp_speed/lib/dispersion/cr72.py
URL: 
http://svn.gna.org/viewcvs/relax/branches/disp_speed/lib/dispersion/cr72.py?rev=23295&r1=23294&r2=23295&view=diff
==============================================================================
--- branches/disp_speed/lib/dispersion/cr72.py  (original)
+++ branches/disp_speed/lib/dispersion/cr72.py  Wed May 21 13:02:55 2014
@@ -92,7 +92,7 @@
 """
 
 # Python module imports.
-from numpy import arccosh, array, cos, cosh, isfinite, max, sqrt, sum
+from numpy import arccosh, array, cos, cosh, isfinite, min, max, sqrt, sum
 
 # Repetitive calculations (to speed up calculations).
 eta_scale = 2.0**(-3.0/2.0)
@@ -128,6 +128,10 @@
     k_BA = pA * kex
     k_AB = pB * kex
 
+    # Catch parameter values that will result in no exchange, returning flat 
R2eff = R20 lines.
+    if dw == 0.0 or pA == 1.0 or kex == 0.0:
+        return array([r20_kex]*num_points)
+
     # The Psi and zeta values.
     if r20a != r20b:
         fact = r20a - r20b - k_BA + k_AB
@@ -156,8 +160,15 @@
 
         return R2eff
 
+    # The arccosh argument - catch invalid values.
+    fact = Dpos * cosh(etapos) - Dneg * cos(etaneg)
+    if min(fact) < 1.0:
+        R2eff = array([r20_kex]*num_points)
+
+        return R2eff
+
     # Calculate R2eff.
-    R2eff = r20_kex - cpmg_frqs * arccosh( Dpos * cosh(etapos) - Dneg * 
cos(etaneg) )
+    R2eff = r20_kex - cpmg_frqs * arccosh( fact )
 
     # Catch errors, taking a sum over array is the fastest way to check for
     # +/- inf (infinity) and nan (not a number).