Changeset 931 for sans/Dev/trunk/NCNR_User_Procedures/Analysis/Models/Teubner_v40.ipf

Timestamp:

Feb 3, 2014 3:36:30 PM (9 years ago)

Author:

srkline

Message:

Two changes to existing model functions:

1) For the 2-yukawa model: Added conditions to enforce Z1>Z2. If this condition is not met, then a valid-looking (but incorrect) S(q) may be returned. These conditions were identified and satisfied within Yun's original Matalb code but were not transferred to the Igor code or XOP. These conditions are enforced within the Igor code before sending to either the XOP or local Igor code.

2) For the Teubner-Strey model: The coefficients have been re-written in terms of the two length scales and a proper absolute scaling. The Macro to calculate the length scales now also reports the amphiphilicity factor.

3) The help file entries for both of these functions have been appropriately updated.

File:

• sans/Dev/trunk/NCNR_User_Procedures/Analysis/Models/Teubner_v40.ipf (modified) (5 diffs)

sans/Dev/trunk/NCNR_User_Procedures/Analysis/Models/Teubner_v40.ipf

@@ -7 +7 @@
 //
 // 06 NOV 98 SRK
+//
+// JAN 2014 - SRK
+//
+// Changed the input parameters to be the length scales rather than a2, c1, c2
+// which have no physical meaning.
 ////////////////////////////////////////////////
 
@@ -17 +22 @@
         Make/O/D/n=(num) xwave_ts,ywave_ts
         xwave_ts =  alog(log(qmin) + x*((log(qmax)-log(qmin))/num))
-        Make/O/D coef_ts = {0.1,-30,5000,0.1}
-        make/o/t parameters_ts = {"scale (a2)","c1","c2","bkg"}
+//      Make/O/D coef_ts = {0.1,-30,5000,0.1}
+//      make/o/t parameters_ts = {"scale (a2)","c1","c2","bkg"}
+
+        Make/O/D coef_ts = {0.3,6e-6,30,100,0.1}
+        make/o/t parameters_ts = {"scale","SLD difference (A^-2)","correlation length (xi) (A)","repeat distance, d, (A)","bkg (1/cm)"}
+
         Edit parameters_ts,coef_ts
         Variable/G root:g_ts
@@ -47 +56 @@
         
         // Setup parameter table for model function
-        Make/O/D smear_coef_ts = {0.1,-30,5000,0.1}
-        make/o/t smear_parameters_ts = {"scale (a2)","c1","c2","bkg"}
+        Make/O/D smear_coef_ts = {0.3,6e-6,30,100,0.1}
+        make/o/t smear_parameters_ts = {"scale","SLD difference (A^-2)","correlation length (xi) (A)","repeat distance, d, (A)","bkg (1/cm)"}
         Edit smear_parameters_ts,smear_coef_ts
         
@@ -73 +82 @@
         Wave cw,yw,xw
 
+        Variable a2, c1, c2
+        Variable d,xi,scale,delrho
+
+        scale = cw[0]
+        delrho = cw[1]
+        xi = cw[2]
+        d = cw[3]
+        
+        
+        a2 = (1 + (2*pi*xi/d)^2)^2
+        c1 = -2*xi*xi*(2*pi*xi/d)^2+2*xi*xi
+        c2 = xi^4       
+        
+        a2 /= 8*pi*xi^3*scale*delrho^2*1e8              //this makes the units work out
+        c1 /= 8*pi*xi^3*scale*delrho^2*1e8
+        c2 /= 8*pi*xi^3*scale*delrho^2*1e8
+        
+//      Print a2,c1,c2
+
+        Duplicate/O cw tmp_ts_cw
+        tmp_ts_cw[0] = a2
+        tmp_ts_cw[1] = c1
+        tmp_ts_cw[2] = c2
+        tmp_ts_cw[3] = cw[4]
+        
 #if exists("TeubnerStreyModelX")
-        yw = TeubnerStreyModelX(cw,xw)
+        yw = TeubnerStreyModelX(tmp_ts_cw,xw)
 #else
-        yw = fTeubnerStreyModel(cw,xw)
+        yw = fTeubnerStreyModel(tmp_ts_cw,xw)
 #endif
         return(0)
@@ -109 +143 @@
         Endif
         // calculate the correlation length and the repeat distance
-        Variable a2,c1,c2,xi,dd
-        a2 = coef_ts[0]
-        c1 = coef_ts[1]
-        c2 = coef_ts[2]
-        
-        xi = 0.5*sqrt(a2/c2) + c1/4/c2
-        xi = 1/sqrt(xi)
-        
-        dd = 0.5*sqrt(a2/c2) - c1/4/c2
-        dd = 1/sqrt(dd)
-        dd *=2*Pi
-        
+//      Variable a2,c1,c2,xi,dd,fa
+//      a2 = coef_ts[0]
+//      c1 = coef_ts[1]
+//      c2 = coef_ts[2]
+//      
+//      xi = 0.5*sqrt(a2/c2) + c1/4/c2
+//      xi = 1/sqrt(xi)
+//      
+//      dd = 0.5*sqrt(a2/c2) - c1/4/c2
+//      dd = 1/sqrt(dd)
+//      dd *=2*Pi
+//              
+
+        Variable a2, c1, c2
+        Variable d,xi,scale,delrho,fa
+        xi = coef_ts[2]
+        d = coef_ts[3]
+        
+        
+        a2 = (1 + (2*pi*xi/d)^2)^2
+        c1 = -2*xi*xi*(2*pi*xi/d)^2+2*xi*xi
+        c2 = xi^4       
+        
+        fa = c1/(sqrt(4*a2*c2))
+                
         Printf "The correlation length (the dispersion of d) xi = %g A\r",xi
-        Printf "The quasi-periodic repeat distance, d = %g A\r",dd
+        Printf "The quasi-periodic repeat distance, d = %g A\r",d
+        Printf "The amphiphilicity factor, fa = %g\r",fa
         
 End