基于matlab的Convection2D内含数据集和源码.zip

function phi = ac_SDF_2D(type, dims, varargin) % FUNCTION U = AC_SDF_2D(TYPE, DIMS, VARARGIN) % Generate some patterns of 2D sign distance functions. % Inputs: % TYPE --- Type of the pattern. Can be one of "circle", "rectangle", % "circle_array" and "chess_box". % DIMS --- Size of the pattern. % VARARGIN --- For "circle", {center, radius}. For "rectangle", % {margin to the boundary}. For "circle_array", {radius of each % circle, distance between ajacent circles}. For "chess_box", % {number of rows, number of columns}. % Output: % U --- Pattern generated as levelset. % % Example: % dims = [300,400]; % center = [100,200]; radius = 100; % phi1 = ac_SDF_2D('circle', dims, center, radius); % % margin = 100; % phi2 = ac_SDF_2D('rectangle', dims, margin); % % radius = 80; circle_distance = 100; % phi3 = ac_SDF_2D('circle_array', dims, radius, circle_distance); % % n_rows = 4; n_cols = 5; % phi4 = ac_SDF_2D('chess_box', dims, n_rows, n_cols); % % figure; % subplot(221); imshow(phi1,[]); % subplot(222); imshow(phi2,[]); % subplot(223); imshow(phi3,[]); % subplot(224); imshow(phi4,[]); % colormap(jet); %% if nargin < 2 || isempty(type) type = 'circle'; end switch lower(type) case 'circle' fcn = @circle_SDF; case 'rectangle' fcn = @rectangle_SDF; case 'circle_array' fcn = @circle_array_SDF; case 'chess_box' fcn = @chess_box_SDF; otherwise error('Unrecognised type %s.', upper(type)); end phi = feval(fcn, dims, varargin{:}); %% function phi = circle_SDF(dims, center, radius) if nargin < 2 center = dims(2:-1:1)/2; end if nargin < 3 radius = 1/3*min(dims); end [X,Y] = meshgrid(1:dims(2),1:dims(1)); phi = radius - sqrt((X-center(1)).^2 + (Y-center(2)).^2); %% function phi = rectangle_SDF(dims, margin) if nargin < 2 margin = 4; end top = margin; left = margin; bottom= dims(1) - margin + 1; right = dims(2) - margin + 1; phi = zeros(dims); phi(top, left:right) = 1; phi(bottom, left:right) = 1; phi(top:bottom, left) = 1; phi(top:bottom, right) = 1; phi = -bwdist(phi); phi(top:bottom, left:right) = - phi(top:bottom, left:right); %% function phi = circle_array_SDF(dims, radius, circle_dist) % circle_dist - distance between two circles phi = zeros(dims); phi(round(circle_dist/2):circle_dist:dims(1),... round(circle_dist/2):circle_dist:dims(2)) = 1; phi = radius - bwdist(phi); %% function phi = chess_box_SDF(dims, n_row, n_col) r = round(1:(dims(1)-1)/n_row:dims(1)); c = round(1:(dims(2)-1)/n_col:dims(2)); % build the signed matrix s = ones(dims); for j = 1:1:length(c)-1 col_idx = c(j):c(j+1)-1; black_or_white = mod(j+1,2); for i = 1:1:length(r)-1 black_or_white = ~black_or_white; if black_or_white s(r(i):r(i+1)-1, col_idx) = -1; end end end % build the zeros set phi = zeros(dims); for i = 1:length(c) phi(:,c(i)) = 1; end for i = 1:length(r) phi(r(i),:) = 1; end % build the SDF phi = bwdist(phi); phi = phi.*s;