mailr20304 - in /branches/relax_disp: lib/dispersion/ns_2site_star.py target_functions/relax_disp.py


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Posted by edward on July 15, 2013 - 18:35:
Author: bugman
Date: Mon Jul 15 18:35:02 2013
New Revision: 20304

URL: http://svn.gna.org/viewcvs/relax?rev=20304&view=rev
Log:
More speed ups of the 'NS 2-site star' dispersion model.

A number of calculations have been shifted to the target function 
initialisation code, avoiding
unnecessary repetitive mathematical operations.


Modified:
    branches/relax_disp/lib/dispersion/ns_2site_star.py
    branches/relax_disp/target_functions/relax_disp.py

Modified: branches/relax_disp/lib/dispersion/ns_2site_star.py
URL: 
http://svn.gna.org/viewcvs/relax/branches/relax_disp/lib/dispersion/ns_2site_star.py?rev=20304&r1=20303&r2=20304&view=diff
==============================================================================
--- branches/relax_disp/lib/dispersion/ns_2site_star.py (original)
+++ branches/relax_disp/lib/dispersion/ns_2site_star.py Mon Jul 15 18:35:02 
2013
@@ -39,7 +39,7 @@
     from scipy.linalg import expm
 
 
-def r2eff_ns_2site_star(Rr=None, Rex=None, RCS=None, R=None, M0=None, 
r20a=None, r20b=None, fA=None, pB=None, tcpmg=None, cpmg_frqs=None, 
back_calc=None, num_points=None):
+def r2eff_ns_2site_star(Rr=None, Rex=None, RCS=None, R=None, M0=None, 
r20a=None, r20b=None, fA=None, pB=None, inv_tcpmg=None, tcp=None, 
back_calc=None, num_points=None, power=None):
     """The 2-site numerical solution to the Bloch-McConnell equation using 
complex conjugate matrices.
 
     This function calculates and stores the R2eff values.
@@ -55,14 +55,16 @@
     @type fA:               float
     @keyword pB:            The population of state B.
     @type pB:               float
-    @keyword tcpmg:         Total duration of the CPMG element (in seconds).
-    @type tcpmg:            float
-    @keyword cpmg_frqs:     The CPMG nu1 frequencies.
-    @type cpmg_frqs:        numpy rank-1 float array
+    @keyword inv_tcpmg:     The inverse of the total duration of the CPMG 
element (in inverse seconds).
+    @type inv_tcpmg:        float
+    @keyword tcp:           The tau_CPMG times (1 / 4.nu1).
+    @type tcp:              numpy rank-1 float array
     @keyword back_calc:     The array for holding the back calculated R2eff 
values.  Each element corresponds to one of the CPMG nu1 frequencies.
     @type back_calc:        numpy rank-1 float array
-    @keyword num_points:    The number of points on the dispersion curve, 
equal to the length of the cpmg_frqs and back_calc arguments.
+    @keyword num_points:    The number of points on the dispersion curve, 
equal to the length of the tcp and back_calc arguments.
     @type num_points:       int
+    @keyword power:         The matrix exponential power array.
+    @type power:            numpy int16, rank-1 array
     """
 
     # The matrix that contains only the R2 relaxation terms ("Redfield 
relaxation", i.e. non-exchange broadening).
@@ -79,9 +81,6 @@
     # This is the complex conjugate of the above.  It allows the chemical 
shift to run in the other direction, i.e. it is used to evolve the shift 
after a 180 deg pulse.  The factor of 2 is to minimise the number of 
multiplications for the prop_2 matrix calculation.
     cR2 = conj(R) * 2.0
 
-    # Replicated calculations for faster operation.
-    inv_tcpmg = 1.0 / tcpmg
-
     # Loop over the time points, back calculating the R2eff values.
     for i in range(num_points):
         # Catch zeros (to avoid matrix log failures).
@@ -89,18 +88,14 @@
             back_calc[i] = 0.0
             continue
 
-        # Replicated calculations for faster operation.
-        tcp = 0.25 / cpmg_frqs[i]
-
         # This matrix is a propagator that will evolve the magnetization 
with the matrix R for a delay tcp.
-        expm_R_tcp = expm(R*tcp)
+        expm_R_tcp = expm(R*tcp[i])
 
         # This is the propagator for an element of [delay tcp; 180 deg 
pulse; 2 times delay tcp; 180 deg pulse; delay tau], i.e. for 2 times 
tau-180-tau.
-        prop_2 = dot(dot(expm_R_tcp, expm(cR2*tcp)), expm_R_tcp)
+        prop_2 = dot(dot(expm_R_tcp, expm(cR2*tcp[i])), expm_R_tcp)
 
         # Now create the total propagator that will evolve the magnetization 
under the CPMG train, i.e. it applies the above tau-180-tau-tau-180-tau so 
many times as required for the CPMG frequency under consideration.
-        power = int(round(cpmg_frqs[i]*tcpmg))
-        prop_total = matrix_power(prop_2, power)
+        prop_total = matrix_power(prop_2, power[i])
 
         # Now we apply the above propagator to the initial magnetization 
vector - resulting in the magnetization that remains after the full CPMG 
pulse train.  It is called M of t (t is the time after the CPMG train).
         Moft = dot(prop_total, M0)

Modified: branches/relax_disp/target_functions/relax_disp.py
URL: 
http://svn.gna.org/viewcvs/relax/branches/relax_disp/target_functions/relax_disp.py?rev=20304&r1=20303&r2=20304&view=diff
==============================================================================
--- branches/relax_disp/target_functions/relax_disp.py (original)
+++ branches/relax_disp/target_functions/relax_disp.py Mon Jul 15 18:35:02 
2013
@@ -24,7 +24,7 @@
 """Target functions for relaxation dispersion."""
 
 # Python module imports.
-from numpy import complex64, dot, float64, zeros
+from numpy import complex64, dot, float64, int16, zeros
 
 # relax module imports.
 from lib.dispersion.cr72 import r2eff_CR72
@@ -151,6 +151,16 @@
             # This is a vector that contains the initial magnetizations 
corresponding to the A and B state transverse magnetizations.
             self.M0 = zeros(2, float64)
 
+            # The tau_cpmg times and matrix exponential power array.
+            self.tau_cpmg = zeros(self.num_disp_points, float64)
+            self.power = zeros(self.num_disp_points, int16)
+            for i in range(self.num_disp_points):
+                self.tau_cpmg[i] = 0.25 / self.cpmg_frqs[i]
+                self.power[i] = int(round(self.cpmg_frqs[i] * 
self.relax_time))
+
+            # The inverted relaxation delay.
+            self.inv_relax_time = 1.0 / relax_time
+
         # Set up the model.
         if model == MODEL_NOREX:
             self.func = self.func_NOREX
@@ -544,15 +554,15 @@
                 dw_frq = dw[spin_index] * self.frqs[spin_index, frq_index]
 
                 # Back calculate the R2eff values.
-                r2eff_ns_2site_star(Rr=self.Rr, Rex=self.Rex, RCS=self.RCS, 
R=self.R, M0=self.M0, r20a=R20A[r20_index], r20b=R20B[r20_index], pB=pB, 
fA=dw_frq, tcpmg=self.relax_time, cpmg_frqs=self.cpmg_frqs, 
back_calc=self.back_calc[spin_index, frq_index], 
num_points=self.num_disp_points)
-
-                # For all missing data points, set the back-calculated value 
to the measured values so that it has no effect on the chi-squared value.
-                for point_index in range(self.num_disp_points):
-                    if self.missing[spin_index, frq_index, point_index]:
-                        self.back_calc[spin_index, frq_index, point_index] = 
self.values[spin_index, frq_index, point_index]
-
-                # Calculate and return the chi-squared value.
-                chi2_sum += chi2(self.values[spin_index, frq_index], 
self.back_calc[spin_index, frq_index], self.errors[spin_index, frq_index])
-
-        # Return the total chi-squared value.
-        return chi2_sum
+                r2eff_ns_2site_star(Rr=self.Rr, Rex=self.Rex, RCS=self.RCS, 
R=self.R, M0=self.M0, r20a=R20A[r20_index], r20b=R20B[r20_index], pB=pB, 
fA=dw_frq, inv_tcpmg=self.inv_relax_time, tcp=self.tau_cpmg, 
back_calc=self.back_calc[spin_index, frq_index], 
num_points=self.num_disp_points, power=self.power)
+
+                # For all missing data points, set the back-calculated value 
to the measured values so that it has no effect on the chi-squared value.
+                for point_index in range(self.num_disp_points):
+                    if self.missing[spin_index, frq_index, point_index]:
+                        self.back_calc[spin_index, frq_index, point_index] = 
self.values[spin_index, frq_index, point_index]
+
+                # Calculate and return the chi-squared value.
+                chi2_sum += chi2(self.values[spin_index, frq_index], 
self.back_calc[spin_index, frq_index], self.errors[spin_index, frq_index])
+
+        # Return the total chi-squared value.
+        return chi2_sum




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