amg_solve.m

五点差分型多重网格方法：各种插值算子的比较）

%AMG_SOLVE
%
%       x = AMG_SOLVE(GUI_HANDLES)
%           GUI_HANDLES allows this function to access the disply in the
%           AMGLab GUI

% Ryan McKenzie
% Department of Computational Sciences
% University of Kentucky

function x = amg_solve(GUI_HANDLES);

amg_globals;
str=get(GUI_HANDLES.panelText,'String');

%Check the source of the problem specification
if PROB_SRC==USER_SPEC_FD %if the user finite difference matrix is to be used
    str=strcat(str,sprintf('\n    Initializing Problem to User Specifications              '));
    str=strcat(str,sprintf('\n    USER: Please enter your input file name at the console...'));
    set(GUI_HANDLES.panelText,'String',str);
    drawnow;
    amg_usersetFD; %set up globals as the user has specified them
elseif PROB_SRC==USER_SPEC_FEM %if the user finite element matrix is to be used
    str=strcat(str,sprintf('\n    Initializing Problem to User Specifications              '));
    str=strcat(str,sprintf('\n    USER: Please enter your input file name at the console...'));
    set(GUI_HANDLES.panelText,'String',str);
    drawnow;
    amg_usersetFEM; %set up globals as the user has specified them
elseif PROB_SRC==EXAMPLE1 %if example 1 is called for
    str=strcat(str,sprintf('\n    Initializing Problem to Poisson Example             '));
    set(GUI_HANDLES.panelText,'String',str);
    drawnow;
    amg_example1; %set up globals for example 1
end

profile clear;

if SETUP_OPT==AT_ONCE %if user wishes to find all coarse grids up front
    % see "restrict.m" for what happens otherwise
    str=strcat(str,sprintf('\n    Calling Setup Algorithm to Determine Coarse Grids   '));
    set(GUI_HANDLES.panelText,'String',str);
    drawnow;
    if SHOW_PROFILE==YES
        profile on;
    end
    amg_setup(1); %call setup algorithm
    if SHOW_PROFILE==YES
        profile off;
    end
end

INIT_RESID = norm(RHS - (A(1).matrix * X_Guess)); %get initial residual
str=strcat(str,sprintf('\n    2-Norm of Initial Residual is %d                     ', INIT_RESID));
set(GUI_HANDLES.panelText,'String',str);
drawnow;

x = X_Guess;
cycleCount = 1; %count the number of AMG cycles executed
while (cycleCount<=CYCLES)
    str=strcat(str,sprintf('\n    Starting AMG Cycle Number %i...                     ', cycleCount));
    set(GUI_HANDLES.panelText,'String',str);
    drawnow;
    if SHOW_PROFILE==YES
        profile resume;
    end
    x = amg_cycle(cycleCount,1,RHS,x); %execute as many AMG cycles if necessary
    if SHOW_PROFILE==YES
        profile off;
    end
    str=strcat(str,sprintf('\n    2-Norm of Residual after AMG Cycle Number %i is %d  ', cycleCount, norm(RH2(cycleCount,1))));
    set(GUI_HANDLES.panelText,'String',str);
    drawnow;
    cycleCount=cycleCount+1; %incriment cycle count
end

FINAL_RESID = norm(RHS - (A(1).matrix * x)); %get initial residual

str=strcat(str,sprintf('\nFinished...                                              '));
set(GUI_HANDLES.panelText,'String',str);
drawnow;

if SHOW_PROFILE==YES
    profile viewer;
end