% File: pde_1.m % From Chapter 14 - 'Diffusion Equation in Spherical Coordinates', % of the book: % William E Schiesser and Graham W Griffiths (2009). % A Compendium of Partial Differential Equation Models % - Method of Lines Analysis with Matlab, % Cambridge University Press (ISBN-13: 9780521519861). function ut=pde_1_mine(t,u) % % Global area global r r0 nr D tau ncall IP %f % % Spatial grid in r for i=1:nr % % ur% u(nr)=IP; ur=dss008(0.0,r0,nr,u); % ur(nr)=0.0; %boundary conditions ur(1)=-10; % % urr urr=dss008(0.0,r0,nr,ur); end % % PDE for i=1:nr if(t<=tau) fs= 0.0; %f(i); else fs=0.0; end % if(i==1) % ut(i)=D*3.0*urr(i)+fs; % else ut(i)=D*(urr(i)+1.0/r(i)*ur(i))+fs; % end end ut=ut'; ut(nr)=0; % % Increment number of calls to pde_1 ncall=ncall+1;