Changeset 5c1d341 in sasmodels

Timestamp:

Jan 20, 2016 9:38:35 AM (9 years ago)

Author:

piotr

Branches:

master, core_shell_microgels, costrafo411, magnetic_model, release_v0.94, release_v0.95, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests

Children:

9eaadb3

Parents:

7ed702f

Message:

Converted MassFractalModel?
Refactored lanczos_gamma (gamln) out

Location:

sasmodels/models

Files:

• img/mass_fractal_1d.jpg (added)
• lib/lanczos_gamma.c (added)
• mass_fractal.c (added)
• mass_fractal.py (added)
• surface_fractal.c (modified) (2 diffs)
• surface_fractal.py (modified) (1 diff)

sasmodels/models/surface_fractal.c

@@ -10 +10 @@
             double surface_dim,
             double cutoff_length);
-
-static double _gamln(double q)
-{
-    // Lanczos approximation to the Gamma function.
-    // Should be refactored out to lib/, if used elsewhere.
-    double x,y,tmp,ser;
-    double coeff[6]=
-        {76.18009172947146,     -86.50532032941677,
-         24.01409824083091,     -1.231739572450155,
-          0.1208650973866179e-2,-0.5395239384953e-5};
-    int j;
-
-    y=x=q;
-    tmp  = x+5.5;
-    tmp -= (x+0.5)*log(tmp);
-    ser  = 1.000000000190015;
-    for (j=0; j<=5; j++) {
-        y+=1.0;
-        ser += coeff[j]/y;
-    }
-    return -tmp+log(2.5066282746310005*ser/x);
-}
 
 static double _surface_fractal_kernel(double q,
@@ -48 +26 @@
     //calculate S(q)
     mmo = 5.0 - surface_dim;
-    sq  = exp(_gamln(mmo))*sin(-(mmo)*atan(q*cutoff_length));
+    sq  = exp(lanczos_gamma(mmo))*sin(-(mmo)*atan(q*cutoff_length));
     sq *= pow(cutoff_length, mmo);
     sq /= pow((1.0 + (q*cutoff_length)*(q*cutoff_length)),(mmo/2.0));

sasmodels/models/surface_fractal.py

@@ -90 +90 @@
 
 
-source = ["lib/J1c.c", "surface_fractal.c"]
+source = ["lib/J1c.c", "lib/lanczos_gamma.c", "surface_fractal.c"]
 
 demo = dict(scale=1, background=0,