Add test results

Author: rfd1

.gitignore

@@ -8,4 +8,5 @@ doc/build/
 archive/
 
 # python
-__pycache__
+__pycache__
+venv/

README.md

@@ -267,7 +267,14 @@ which looks like
 
 ![parameters](out/figure7.png "Figure 7")
 
-and Figure 8,
+The association constant is calculated as
+
+    >>> K_a = DS.get_K()/2/C_REF*1e-6
+    >>> d_K_a = DS.get_K_std()/2/C_REF*1e-6
+    >>> "K_a at %3.2f K is %f +/- %f" % (DS.T[-24], K_a[-24], 3.*d_K_a[-24])
+    'K_a at 295.00 K is 0.671648 +/- 0.033107'
+
+We plot Figure 8 via
 
     >>> from src.plot_params import plot_figure8
     >>> plot_figure8(SS, DS)