Set methods to static if possible.

Troubled_Cell_Detector.py

@@ -86,7 +86,8 @@ class TroubledCellDetector(object):
 
         return max_error
 
-    def _plot_solution_and_approx(self, grid, exact, approx, color_exact, color_approx):
+    @staticmethod
+    def _plot_solution_and_approx(grid, exact, approx, color_exact, color_approx):
         print(color_exact, color_approx)
         plt.figure(1)
         plt.plot(grid[0], exact[0], color_exact)
@@ -95,14 +96,16 @@ class TroubledCellDetector(object):
         plt.ylabel('u(x,t)')
         plt.title('Solution and Approximation')
 
-    def _plot_semilog_error(self, grid, pointwise_error):
+    @staticmethod
+    def _plot_semilog_error(grid, pointwise_error):
         plt.figure(2)
         plt.semilogy(grid[0], pointwise_error[0])
         plt.xlabel('x')
         plt.ylabel('|u(x,t)-uh(x,t)|')
         plt.title('Semilog Error plotted at Evaluation points')
 
-    def _plot_error(self, grid, exact, approx):
+    @staticmethod
+    def _plot_error(grid, exact, approx):
         plt.figure(3)
         plt.plot(grid[0], exact[0]-approx[0])
         plt.xlabel('X')