仅就作图而言，Python 和 MATLAB 有可比性吗？

       clear;clc;close all; x = linspace(1, 200, 100); y1 = log(x) + 1; y2 = log(x) + 2; figure; plot(x, y1); hold on plot(x, y2, 'LineWidth', 2); hold off legend('y1', 'y2');     

       figure; plot(x, y1, 'LineWidth', 2, 'Color', [0.21, 0.21, 0.67]); hold on plot(x, y2, 'LineWidth', 2, 'Color', [0.99, 0.49, 0.00]); hold off legend('y1', 'y2');     

       figure; y3 = y1 + rand(1, 100) - 0.5; plot(x, y1, 'LineWidth', 2, 'Color', [0.21, 0.21, 0.67]); hold on % 设置数据点的形状、数据点的填充颜色、数据点的轮廓颜色 plot(x, y3, 'o', 'LineWidth', 2, 'Color', [0.46, 0.63, 0.90], 'MarkerFaceColor', [0.35, 0.90, 0.89], 'MarkerEdgeColor', [0.18, 0.62, 0.17]); hold off     

       % 先自己做一个 colormap c_map =  [0.00, 0.36, 0.67           0.68, 0.42, 0.89           0.44, 0.62, 0.98           0.10, 0.67, 0.59           0.99, 0.57, 0.59           0.28, 0.55, 0.86           0.96, 0.62, 0.24           0.30, 0.90, 0.56           0.12, 0.46, 0.71           0.46, 0.63, 0.90           0.96, 0.37, 0.40           0.14, 0.76, 0.71           0.99, 0.50, 0.02           0.00, 0.57, 0.76           0.35, 0.90, 0.89           0.17, 0.62, 0.47           0.21, 0.21, 0.67           0.99, 0.49, 0.00           0.98, 0.74, 0.44           0.97, 0.60, 0.58           0.18, 0.62, 0.17           0.68, 0.87, 0.53           0.12, 0.46, 0.70           0.65, 0.79, 0.89           0.95, 0.99, 0.69           0.74, 0.92, 0.68           0.37, 0.81, 0.72           0.01, 0.72, 0.77]; scatter(x, y3, x, x, 'filled'); colormap(c_map);     

       figure; fill([x, NaN], [y2, NaN], [x, NaN], 'EdgeColor', 'interp', 'LineWidth', 2);     

       figure; m = 5; n = 3; x = 1:m; y = rand(m, n) + 2; % 误差限 neg = rand(m, n); pos = rand(m, n); % 绘制柱状图 h = bar(x, y); % 设置三个系列颜色 h(1, 1).FaceColor = [0.00, 0.36, 0.67]; h(1, 2).FaceColor = [0.68, 0.42, 0.89]; h(1, 3).FaceColor = [0.44, 0.62, 0.98]; % 单独设置第二个系列第二个柱子颜色 h(1, 2).FaceColor = 'flat'; h(1, 2).CData(2,:) = [0.21, 0.21, 0.67];  % 获取误差线 x 值 xx = zeros(m, n); for i = 1 : n     xx(:, i) = h(1, i).XEndPoints';  end % 绘制误差线 hold on errorbar(xx, y, neg, pos, 'LineStyle', 'none', 'Color', 'm', 'LineWidth', 1.5); hold off % 绘制图例 legend({'A1', 'A2', 'A3'}); % 设置 x 轴标签 set(gca, 'XTickLabel', {'label1', 'label2', 'label3', 'label4', 'label5'});     

       x = 0.4:0.1:2*pi; y1 = sin(2*x); y2 = sin(x); % 确定 y1 和 y2 的上下边界 maxY = max([y1; y2]); minY = min([y1; y2]); % 确定填充多边形，按照顺时针方向来确定点 % fliplr 实现左右翻转 xFill = [x, fliplr(x)]; yFill = [maxY, fliplr(minY)]; figure fill(xFill, yFill, [0.21, 0.21, 0.67]); hold on % 绘制轮廓线 plot(x, y1, 'k', 'LineWidth', 2) plot(x, y2, 'k', 'LineWidth', 2) hold off     

       % 函数交叉区域填充 figure; % 这是三个方程 g1 = @(x,y) 1 - x.^2.*y/20; g2 = @(x, y) 1 - (x+y-5).^2/30 - (x-y-12).^2/120; g3 = @(x, y) 1 - 80./(x.^2 + 8*y + 5); % 把他们的图像画出来 h1 = fimplicit(g1, [0, 10], 'LineWidth', 2); hold on h2 = fimplicit(g2, [0, 10], 'LineWidth', 2); h3 = fimplicit(g3, [0, 10], 'LineWidth', 2); legend('g1', 'g2', 'g3'); % 问题来了，这个 y 值怎么确定 x1 = h1.XData; y1 = h1.YData; x2 = h2.XData; y2 = h2.YData; x3 = h3.XData; y3 = h3.YData; % 发现 x1, x2 是从大到小的，逆序搞一下 x1 = fliplr(x1); x2 = fliplr(x2); y1 = fliplr(y1); y2 = fliplr(y2); % 接下来，确定相交区域，主要看这三个关键点：g1-g2, g1-g3, g2-g3 % 数据长度不一样，难搞了，借助【数据提示】功能吧 pt1 = [3.11069, 2.06667]; pt2 = [8.53623, 0.266667]; pt3 = [7.7847, 1.8]; % 确定三个范围 idx1 = find(x1 >= pt1(1) & x1 < pt2(1)); idx2 = find(x2 >= pt1(1) & x2 < pt3(1)); idx3 = find(x3 >= pt3(1) & x3 < pt2(1)); x1 = x1(idx1); x2 = x2(idx2); x3 = x3(idx3); y1 = y1(idx1); y2 = y2(idx2); y3 = y3(idx3); % 一定要是一个闭环 xFill = [x1, fliplr(x3), fliplr(x2)]; yFill = [y1, fliplr(y3), fliplr(y2)]; fill(xFill, yFill, [0.21, 0.21, 0.67]); hold off     

       figure; load('accidents.mat','hwydata') ind = 1:51; drivers = hwydata(:,5); yyaxis left scatter(ind, drivers, 'LineWidth', 2); title('Highway Data'); xlabel('States'); ylabel('Licensed Drivers (thousands)'); pop = hwydata(:,7); yyaxis right scatter(ind, pop, 'LineWidth', 2); ylabel('Vehicle Miles Traveled (millions)');     

       figure; x = linspace(0,10); y1 = 2*sin(3*x); y2 = sin(3*x).*exp(0.5*x); %% 三个纵坐标演示，更多纵坐标可以按照此方法类推 y3 = 10*cos(3*x); % 控制 aies 的大小和位置，注意是相对于figure的，范围为[0, 1] % 三条线绘制到一起，注意数据都标准化到 y1 范围 maxY1 = max(y1); maxY2 = max(y2); maxY3 = max(y3); minY1 = min(y1); minY2 = min(y2); minY3 = min(y3); newY2 = (y2 - minY2)/(maxY2 - minY2);   % 归一化 newY2 = newY2*(maxY1 - minY1) + minY1;  % 反归一化 newY3 = (y3 - minY3)/(maxY3 - minY3); newY3 = newY3*(maxY1 - minY1) + minY1; % 画线 axes('position', [0.1 0.1 0.5 0.5]);    plot(x, y1, 'k', x, newY2, 'r', x, newY3, 'ob--') ylabel('line1'); % 绘制另外两个空的坐标轴 h2 = axes('position', [0.65 0.1 0.005 0.5]);  % 重复绘制，曲线颜色用白色，和figure背景色一致，看不出来即可 plot(x, y2, 'w') % 颜色，位置，曲线标签 set(h2, 'ycolor', 'r', 'yaxislocation', 'right', 'xtick', []) % 不知道为啥2018B版本边界显示不清楚，所以画一条线 hold on limX2 = get(h2, 'Xlim'); limY2 = get(h2, 'Ylim'); plot([limX2(2), limX2(2)], limY2, 'r'); hold off % 取消边框 box off ylabel('line2'); % h3 = axes('position', [0.75 0.1 0.005 0.5]);  plot(x, y3, 'w') set(h3, 'ycolor', 'b', 'yaxislocation', 'right', 'xtick', []) hold on limX3 = get(h3, 'Xlim'); limY3 = get(h3, 'Ylim'); plot([limX3(2), limX3(2)], limY3, 'b'); hold off box off ylabel('line3'); % 取消坐标轴的颜色，和figure统一 % set(h1, 'color','none') % set(h2, 'color','none') % set(h3, 'color','none') % figure背景设置成白色 set(gcf,'color','white');      

       % 直接把 streamline 函数的帮助文档 demo 拷贝过来  [x, y] = meshgrid(0:0.1:1, 0:0.1:1); u = x; v = -y; startx = 0.1:0.1:0.9; starty = ones(size(startx)); % 需要获取所有流线的属性 figure; quiver(x, y, u, v); streamline(x, y, u, v, startx, starty);     

       % 直接把 streamline 函数的帮助文档 demo 拷贝过来  figure; [x, y] = meshgrid(0:0.1:1, 0:0.1:1); u = x; v = -y; startx = 0.1:0.1:0.9; starty = ones(size(startx)); % 需要获取所有流线的属性 lines = streamline(x, y, u, v, startx, starty); % 下面开始画箭头，涉及到坐标的转换 % 获取 Axes 位置 posAxes = get(gca, 'Position'); posX = posAxes(1); posY = posAxes(2); width = posAxes(3); height = posAxes(4); % 获取 Axes 范围 limX = get(gca, 'Xlim'); limY = get(gca, 'Ylim'); minX = limX(1); maxX = limX(2); minY = limY(1); maxY = limY(2); % 遍历，逐条流线加箭头 for i = 1 : length(lines)     % 获取每条流线的数据     xData = lines(i).XData;     yData = lines(i).YData;     % 这里取的是最后两个点，一定要是相邻的两个点用来确定箭头方向     x0 = xData(end-1 : end);     y0 = yData(end-1 : end);     % 转换坐标到相对于figure的坐标     xNew = posX + (x0 - minX) / (maxX - minX) * width;     yNew = posY + (y0 - minY) / (maxY - minY) * height;     % 画箭头     hold on     annotation('arrow', xNew, yNew, 'color', 'b'); end hold off title('带箭头的流线图');     

       figure; t = 0:pi/20:10*pi; xt = sin(t); yt = cos(t); plot3(xt, yt, t, '-o', 'Color', 'b', 'MarkerSize', 10, 'MarkerFaceColor', '#D9FFFF');     

       figure; x = -20:10:20; y = 0:100; % 随便生成的 5 组数据，也就是目标图上的 5 条曲线数据 z = zeros(5, 101); z(1, 1:10:end) = linspace(1, 10, 11); z(2, 1:10:end) = linspace(1, 20, 11); z(3, 1:10:end) = linspace(1, 5, 11); z(4, 5:10:end) = linspace(1, 10, 10); z(5, 80:2:end) = linspace(1, 5, 11); for i = 1:5     % x 方向每条曲线都是一个值，重复 y 的长度这么多次      xx = x(i)*ones(1, 101);     % z 方向的值，每次取一条     zz = z(i, :);     % plot3 在 xyz 空间绘制曲线，保证 x y z 长度一致即可     plot3(xx, y, zz, 'LineWidth', 2);     hold on end hold off legend('line1', 'line2', 'line3', 'line4', 'line5');     

       % 如果把渐变曲线和三维曲线结合起来 figure; x = linspace(0, 2*pi, 50); y = sin(x); fill3([ones(size(x)), NaN], [x, NaN], [y, NaN], [x NaN], 'EdgeColor', 'interp', 'LineWidth', 2) hold on for i = 2 : 5     if mod(i, 2) == 0         y = sin(2*x);         fill3([i * ones(size(x)), NaN], [x, NaN], [y, NaN], [x NaN], 'EdgeColor', 'interp', 'LineWidth', 2)     else         y = sin(10*x);         fill3([i * ones(size(x)), NaN], [x, NaN], [y, NaN], [x NaN], 'EdgeColor', 'interp', 'LineWidth', 2)     end end hold off     

       figure; [X,Y,Z] = sphere(16); x = [0.5*X(:); 0.75*X(:); X(:)]; y = [0.5*Y(:); 0.75*Y(:); Y(:)]; z = [0.5*Z(:); 0.75*Z(:); Z(:)]; S = repmat([70, 50, 20],numel(X), 1); C = repmat([1, 2, 3], numel(X), 1); s = S(:); c = C(:); h = scatter3(x, y, z, s, c); h.MarkerFaceColor = [0 0.5 0.5];     

       x = linspace(1, 200, 100); y1 = log(x) + 1; y2 = log(x) + 2; y3 = y1 + rand(1, 100) - 0.5; figure; scatter3(x, y2, y3, x, x, 'filled'); colormap(c_map);     

       [x, y, z] = peaks(30); figure; plot1 = subplot(1,2,1); surf(x, y, z); % 获取第一幅图的 colormap，默认为 parula cMap = colormap; plot2 = subplot(1,2,2); surf(x, y, z); % 下面设置的是第二幅图的颜色，默认是整个 figure 的 colormap(hot); % 设置第一幅图颜色显示为 parula set(plot1, 'Colormap', cMap);     

       % 一个坐标轴 figure; h1 = surf(x, y, z); freezeColors; hold on h2 = surf(x, y, z + 5); hold off colormap(hot);     

       figure; n = 300; [x, y, z] = peaks(n); subplot(2, 2, [1,3]) surf(x, y, z); shading interp view(0, 90) for i = 1:n     for j = 1:n         if x(i, j)^2 + 2 * y(i, j)^2 > 6 && 2 * x(i, j)^2 + y(i, j)^2 < 6             z(i, j) = NaN;         end     end end subplot(2, 2, 2) surf(x, y, z); shading interp view(0, 90) subplot(2, 2, 4) surf(x, y, z); shading interp     

       figure; [X, Y, Z] = peaks; subplot(2, 2, 1); contour(X, Y, Z, 20, 'LineWidth', 2); subplot(2, 2, 2); contour(X, Y, Z, '--', 'LineWidth', 2) subplot(2, 2, 3); v = [1, 1]; contour(X, Y, Z, v, 'LineWidth', 2); x = -2:0.2:2; y = -2:0.2:3; [X, Y] = meshgrid(x, y); Z = X.*exp(-X.^2-Y.^2); subplot(2, 2, 4); contour(X, Y, Z, 'ShowText','on', 'LineWidth', 2);     

       figure('Position', [0, 0, 900, 400]); subplot(1, 3, 1); [X, Y, Z] = sphere(50); contour3(X, Y, Z, 'LineWidth', 2); [X, Y] = meshgrid(-2:0.25:2); Z = X.*exp(-X.^2-Y.^2); subplot(1, 3, 2); contour3(X, Y, Z, [-0.2 -0.1 0.1 0.2], 'ShowText', 'on', 'LineWidth', 2) [X, Y, Z] = peaks; subplot(1, 3, 3); contour3(X, Y, Z, [2 2], 'LineWidth', 2);     

       figure; subplot(2, 2, 1); [X, Y, Z] = peaks(50); contourf(X, Y, Z); subplot(2, 2, 2); contourf(X, Y, Z,'--'); % 限定范围 subplot(2, 2, 3); contourf(X, Y, Z, [2 3], 'ShowText', 'on'); subplot(2, 2, 4); contourf(X, Y, Z,[2 2]);     

       figure; [X, Y, Z] = peaks(30); % 矢量场，曲面法线 [U, V, W] = surfnorm(X, Y, Z);    % 箭头长度、颜色 quiver3(X, Y, Z, U, V, W, 0.5, 'r');      hold on surf(X,Y,Z);   xlim([-3, 3]); ylim([-3, 3.2]); shading interp hold off view(0, 90);     

       clear;clc;close all; x = linspace(-3, 3, 30); y = linspace(-4, 4, 40); [X, Y] = meshgrid(x, y); Z = peaks(X, Y); Z(5:10, 15:20) = 0; z1 = max(Z); z2 = max(Z, [], 2); figure; subplot(3, 3, [1, 2]); plot(x, z1, 'LineWidth', 2); subplot(3, 3, [6, 9]); plot(z2, y, 'LineWidth', 2); subplot(3, 3, [4, 5, 7, 8]); surf(x, y, Z); xlim([-3, 3]); ylim([-4, 4]); view(0, 90); shading interp     

       figure; % 3*3 布局 tiledlayout(3, 3, 'TileSpacing', 'Compact'); % 占据 1*2，也就是 1 2 nexttile([1, 2]); plot(x, z1, 'LineWidth', 2); % 从第 6 个开始，占据 2*1，也就是 6 和 9 nexttile(6, [2, 1]); plot(z2, y, 'LineWidth', 2); % 从第 4 个开始，占据 2*2，也就是 4 5 7 8 nexttile(4, [2, 2]); surf(x, y, Z); xlim([-3, 3]); ylim([-4, 4]); view(0, 90); shading interp     

       clear;clc; x = linspace(-10, 10, 100); y = gauss(100, 5) ;  figure; % 设置边缘颜色和宽度 bar(x, y, 'EdgeColor', 'none', 'BarWidth', 1);     

       clear;clc; z = rand(50); z(z >= 0.0 & z < 0.6) = 0.5; z(z >= 0.6 & z < 0.8) = 0.7; z(z >= 0.8 & z <= 1) = 0.9;  for i = 1:30     z(randi(50, 1, 1) : end, i) = nan; end for i = 31:50     z(30 + randi(20, 1, 1) : end, i) = nan; end z(20:25, 40:45) = nan; figure; % ax = surf(z); ax = pcolor(z); view(0, 90); ax.EdgeColor = [1 1 1]; axis off     

       figure; for i = 1:50     for j = 1:50         if ~isnan(z(i, j))             x = [i - 1, i, i, i - 1];             y = [j - 1, j - 1, j, j];             c1 = 'w';             c2 = 'w';             if z(i, j) >= 0.1                 c1 = 'black';                 c2 = [0.65, 0.78, 0.56];                 if z(i, j) >= 0.6                     c2 = [0.98, 0.46, 0.23];                     if z(i, j) >= 0.8                         c2 = [0.99, 0.02, 0.02];                     end                 end             end             patch(x, y, c2, 'EdgeColor', c1);         end      end end axis off     

       clear;clc; % 球面的坐标信息，为了看起来平滑一点，给到 100 [x, y, z] = sphere(100); % C 大小 C = 10;  % H 大小 H = 5; figure; % 大球 surf(C*x, C*y, C*z, 'FaceColor', 'red', 'EdgeColor', 'none') hold on  % 四个小球，都偏离一点位置，准确的位置需要计算，这里演示一个大概位置 surf(H*x, H*y, H*z + 10, 'FaceColor', 'blue', 'EdgeColor', 'none'); surf(H*x + 10, H*y, H*z - 3, 'FaceColor', 'blue', 'EdgeColor', 'none'); surf(H*x - 4, H*y - 10, H*z - 3, 'FaceColor', 'blue', 'EdgeColor', 'none'); surf(H*x - 4, H*y + 10, H*z - 3, 'FaceColor', 'blue', 'EdgeColor', 'none'); % 坐标轴设置 axis equal off % 光源，看起来更有立体感 light lighting gouraud     

       clear;clc; n = 1000; m = 1000; f = @(z) z^8 - 1; df = @(z) 8*z^7; [X, Y] = meshgrid(linspace(-2, 2, n), linspace(-2, 2, m)); A = nan(n, m); for i = 1:n     for j = 1:m         z0 = X(i, j) + 1i*Y(i, j);         % Newton-Raphson         z = z0;         ite = 0;         fz = f(z);         while abs(fz) > 1e-6 && ite < 20             z = z - f(z)/df(z);              fz = f(z);             ite = ite + 1;         end         A(i, j) = ite;     end end figure; pcolor(X, Y, A); % hold on % plot([1, -1, 0, 0], [0, 0, 1, -1], '.k', 'MarkerSize', 20); % hold off shading flat axis tight manual      

       % xlim([-0.5, 0]); % ylim([0.5, 1]); % 保存成视频 % set(gca, 'nextplot', 'replacechildren');  % v = VideoWriter('NRfractal.avi'); % open(v); % for k = 1:20  %     pcolor(X, Y, A); %     shading flat %     xlim([-2*(1-k/25), 2*(1-k/25)]); %     ylim([-2*(1-k/25), 2*(1-k/25)]); %     frame = getframe(gcf); %     writeVideo(v, frame); % end  % (-0.19, 0.6557) % (-0.1, 0.651) % zx = zx*zx - zy*zy + cx % zy = 2*zx*zy+cy c = - 0.1 + 1i*0.651; radius = 32; [X, Y] = meshgrid(linspace(-1.5, 1.5, n), linspace(-1.5, 1.5, m)); A = nan(n, m); for i = 1:n     for j = 1:m         z = X(i, j) + 1i*Y(i, j);         % Julia         for ite = 1:1000             z = (z*z + c) ;             if abs(z) > radius                 break;             end         end         A(i, j) = ite;     end end figure; pcolor(X, Y, A); shading flat axis tight manual     

       clear;clc; figure; % 读取地图文件 image = imread('World.jpg');  % 生成一个球面数据 [x, y, z] = sphere(200); % 绘制球体 p = surf(x, y, z);  % 去网格线 shading interp; p.CData = image;  % 纹理贴图 p.FaceColor = "texturemap";  axis equal; axis off % 光源，看起来更有立体感 % light % lighting gouraud % 光源颜色 handle = light('Color', [1 1 1]); t = 0; while t < 100     t = t + 1;     view([t 10]);     lightangle(handle, t, 0);     pause(0.01); end     

       clear;clc; N = 500; z = peaks(N); % 选择 ROI 以外的不显示 for i = 1:N     for j = 1:N         if sqrt((i - N/2)*(i - N/2) + (j - N/2)*(j - N/2)) > 240             z(i, j) = nan;         end     end end % 自定义颜色 大概就是给特定范围值指定颜色 N = 14 * 5; crange = linspace(-6, 8, N); cmap = zeros(N, 3); for i = 1:N     if crange(i) <= 0         cmap(i, :) = [0, 1, 0];     elseif crange(i) <= 3         cmap(i, :) = [0, 0, 1];     elseif crange(i) <= 6         cmap(i, :) = [1, 1, 0];     else         cmap(i, :) = [1, 0, 0];     end end figure; surf(z) colormap(cmap); % 去网格 shading interp % 视角 view(0, 90); % 去坐标轴 axis off     

       clear; clc; x = 0:0.01:1; n = 1:9; len = length(n); im = cell(1, len); % 单独显示每个图 figure; for idx = 1:len     subplot(3, 3, idx)     plot(x, x.^idx, 'LineWidth',3)     title(['y = x^', num2str(idx)]) end % 获取绘制对象 fig = figure(1); for idx = 1:len     y = x.^idx;     plot(x, y, 'LineWidth', 3)     title(['y = x^', num2str(n(idx))]) %     drawnow %     pause(0.1);     frame = getframe(fig);     im{idx} = frame2im(frame); end % 输出文件名 % filename = 'testAnimated.gif';  % for idx = 1:len %     % 制作gif文件，图像必须是index索引图像 %     [A, map] = rgb2ind(im{idx}, 256); %     if idx == 1 %         imwrite(A, map, filename, 'gif', 'LoopCount', Inf, 'DelayTime', 0.3); %     else %         imwrite(A, map, filename, 'gif', 'WriteMode', 'append', 'DelayTime', 0.3); %     end % end     

       % 二元方程  x^2*cos(y) + x*sinh(y^2) = 0 xy = linspace(-2, 2, 4); f = @(x, y) x.^2.*cos(y) + x.*sinh(y.^2); figure fimplicit(f, [-2, 2]);     

       figure; theta = 0:0.01:2*pi; rho = sin(2*theta).*cos(2*theta); tiledlayout(1, 2); nexttile; polarplot(theta, rho, 'c', 'LineWidth', 2); nexttile; rMax = 2*max(rho); % 这个看不到线，因为只有一个重复的点 polarplot([0, 2*pi], [rMax, rMax]);     hold on polarplot(theta, rho, 'm', 'LineWidth', 2); hold off     

       clear;clc;close all; % 限定范围 width = 10;   height = 10; % 最多产生的圆的个数 circleNumber = 100;    % 记录每个圆的横坐标、纵坐标、半径 paras = zeros(circleNumber, 3);   num = 0; hold on while num < circleNumber     num = num + 1;         % 圆半径小于1或者设定为固定值     r = rand;      % 在范围内随机坐标     xPos = rand*(width-2*r) + r;       yPos = rand*(height-2*r) + r;     % 记录坐标、半径     paras(num,:) = [xPos, yPos, r];     % 判断每个圆的位置是否不相切、不相交     if num > 1         % 新产生的圆和之前产生的所有圆计算距离                 xs = paras(1:num - 1, 1);         ys = paras(1:num - 1, 2);         rs = paras(1:num - 1, 3);         dist1 = sqrt((xPos - xs).^2 + (yPos - ys).^2);         dist2 = abs(r + rs);         % 如果相离则绘制当前产生的圆，否则就重新生成一个圆         if all(dist1 > dist2)             rectangle('Position', [xPos-r, yPos-r, 2*r, 2*r], 'Curvature', [1 1]);             axis equal         else             r = rand;              xPos = rand*(width-2*r) + r;               yPos = rand*(height-2*r) + r;             paras(num,:) = [xPos,yPos,r];             % 防止死循环             temp = 0;             maxTry = 100;             while any(dist1 <= dist2) && temp < maxTry                 temp = temp + 1;                 dist1 = sqrt((xPos - xs).^2 + (yPos - ys).^2);                 dist2 = abs(r + rs);             end             if all(dist1 > dist2)                 rectangle('Position', [xPos-r, yPos-r, 2*r, 2*r], 'Curvature', [1 1]);                 axis equal             end         end           end end axis([0 width 0 height]) box on hold off     

       figure; x1 = ones(1, 5); x2 = 2 * ones(1, 11); x3 = 3 * ones(1, 8); y1 = 4:8; y2 = 1:11; y3 = 2.5:9.5; for i = 1:5     for j = 1:11         plot([x1(i), x2(j)], [y1(i), y2(j)], 'k');         hold on     end end for i = 1:11     for j = 1:8         plot([x2(i), x3(j)], [y2(i), y3(j)], 'k');     end end scatter(x1, y1, 200, 'k', 'MarkerFaceColor', 'r'); scatter(x2, y2, 200, 'k', 'MarkerFaceColor', 'y'); scatter(x3, y3, 200, 'k', 'MarkerFaceColor', 'k'); plot([1.5, 1.5], [0, 11], 'k--'); plot([2.5, 2.5], [0, 11], 'k--'); hold off axis off text(1.5, 11.75, '输入层'); text(2, 11.75, '隐藏层'); text(2.5, 11.75, '输出层');     

       clear;clc; x0 = 0; y0 = 0; r1 = 2; r2 = 1; theta = 0:pi/50:2*pi; for i = 1:length(theta)     % 系列小圆的圆心坐标 极坐标方式     x = x0 + r1 * cos(theta(i));     y = y0 + r1 * sin(theta(i));     % 以小圆圆心画圆 极坐标方式     xx = x + r2 * cos(theta);     yy = y + r2 * sin(theta);     plot(xx, yy, 'k');     hold on end hold off % 限定显示范围 xlim([-3, 3]); ylim([-3, 3]); % x y 轴等宽 axis equal % 紧凑 axis tight     

       figure; % 生成数据点 [x, y] = meshgrid(30:39); x = x(:); y = y(:); scatter(x, y, 100, 'red'); hold on % 随机填充几个点 number = 5; index_x = randi(9, 1, number) + 30; index_y = randi(9, 1, number) + 30; scatter(index_x, index_y, 100, 'blue', 'MarkerFaceColor', 'blue'); hold off % 显示网格 grid on % 网格属性 set(gca, 'GridAlpha', 1, 'GridColor', [0 0 0], 'GridLineStyle', '--');