Changeset cd23f31 in sasmodels for example/weights/maier_saupe.py

Timestamp:

Sep 14, 2018 8:44:23 AM (6 years ago)

Author:

Paul Kienzle <pkienzle@…>

Branches:

master

Children:

a5516b1

Parents:

b50e28b

Message:

update maier_saupe docs with P_2 inverse

File:

• example/weights/maier_saupe.py (modified) (3 diffs)

example/weights/maier_saupe.py

@@ -59 +59 @@
             return 1.5*r - 0.75/a - 0.5
 
+    Given an order parameter $S = P_2(a)$, one can also solve for the
+    equivalent $a$:
+
+        from scipy.optimize import fsolve
+
+        def P_2_inv(S):
+            return fsolve(lambda x: P_2(x) - S, 1.0)[0]
+
     References
     ----------
@@ -103 +111 @@
     return 1.5*r - 0.75/a - 0.5
 
+def P_2_inv(S):
+    from scipy.optimize import fsolve
+    return fsolve(lambda x: P_2(x) - S, 1.0)[0]
+
 def P_2_numerical(a):
     from scipy.integrate import romberg
@@ -116 +128 @@
     a = float(sys.argv[1])
     #print("P_2", P_2(a), "difference from integral", P_2(a) - P_2_numerical(a))
-    print("P_2", P_2(a))
+    print("P_2, P_2_inv", P_2(a), P_2_inv(P_2(a)))