Optimizations

Author: AndreyAPopov

src/+otp/+qg/QuasiGeostrophicProblem.m

@@ -158,11 +158,16 @@ function onSettingsChanged(obj)
             %[P2, D] = eig(nfLy);
 
             % We can represent the eigenvalues as
-            dLambda = (4/(hx^2) * (sin(pi*(1:nx)/(2*(nx + 1))).^2)).';
-            dD = (4/(hy^2) * (sin(pi*(1:ny)/(2*(ny + 1))).^2)).';
-            L12 = 1./(dLambda + dD.');
-            P1 = sqrt(2/(nx + 1))*sin((1:nx).'*(1:nx)*pi/(nx + 1));
-            P2 = sqrt(2/(ny + 1))*sin((1:ny).'*(1:ny)*pi/(ny + 1));
+            %dLambda = ((2*sinpi((1:nx)/(2*(nx + 1)))/hx).^2).';
+            %dD = ((2*sinpi((1:ny)/(2*(ny + 1)))/hy).^2).';
+            %L12 = 1./(dLambda + dD.');
+            hx2 = hx^2;
+            hy2 = hy^2;
+            cx = (1:nx)/(nx + 1);
+            cy = (1:ny)/(ny + 1);
+            L12 = -(hx2*hy2./(2*(-hx2 - hy2 + hy2*cospi(cx).' + hx2*cospi(cy))));
+            P1 = sqrt(2/(nx + 1))*sinpi((1:nx).'*(1:nx)/(nx + 1));
+            P2 = sqrt(2/(ny + 1))*sinpi((1:ny).'*(1:ny)/(ny + 1));
 
 
             %L12 = 1./(diag(Lambda) + diag(D).');