www.gusucode.com > pde 案例源码 matlab代码程序 > pde/EvaluateGradientsForScalarEllipticProblemExample.m

    %% Evaluate Gradients for Scalar Elliptic Problem
% Evaluate gradients of the solution to a scalar elliptic problem along a
% line. Plot the results.
%%
% Create the solution to the problem $- \Delta u = 1$ on the L-shaped
% membrane with zero Dirichlet boundary conditions.
model = createpde;
geometryFromEdges(model,@lshapeg);
applyBoundaryCondition(model,'dirichlet','edge',1:model.Geometry.NumEdges,'u',0);
specifyCoefficients(model,'m',0,...
                          'd',0,...
                          'c',1,...
                          'a',0,...
                          'f',1);
generateMesh(model,'Hmax',0.05);
results = solvepde(model);
%%
% Evaluate gradients of the solution along the straight line from |(x,y) =
% (-1,-1)| to |(1,1)|. Plot the results as a quiver plot by using |quiver|.
xq = linspace(-1,1,101);
yq = xq;
[gradx,grady] = evaluateGradient(results,xq,yq);

gradx = reshape(gradx,size(xq));
grady = reshape(grady,size(yq));

quiver(xq,yq,gradx,grady)
xlabel('x')
ylabel('y')