Partial Differential Equation Toolbox™

pdeadgsc - Select triangles using relative tolerance criterion

Syntax

bt=pdeadgsc(p,t,c,a,f,u,errf,tol)

Description

bt=pdeadgsc(p,t,c,a,f,u,errf,tol) returns indices of triangles to be refined in bt. Used from adaptmesh to select the triangles to be further refined. The geometry of the PDE problem is given by the mesh data p and t. For more details, see the entry on initmesh.

c,a, and f are PDE coefficients. For details, see assempde.

u is the current solution, given as a column vector. For details, see assempde.

errf is the error indicator, as calculated by pdejmps.

tol is a tolerance parameter.

Triangles are selected using the criterion errf>tol*scale, where scale is calculated as follows:

Let cmax, amax, fmax, and umax be the maximum of c, a, f, and u, respectively. Let l be the side of the smallest axis-aligned square that contains the geometry.

Then scale=max(fmax*l^2,amax*umax*l^2,cmax*umax). The scaling makes the tol parameter independent of the scaling of the equation and the geometry.

See Also

parabolic

pdeadworst