四課數(shù)據(jù)可視化課件

1、第四課數(shù)據(jù)可視化二維繪圖三維繪圖顯示圖像實驗內(nèi)容：用圖形表示離散函數(shù)n = 0:12;y=1./abs(n+eps-6);plot(n,y,r*,MarkerSize,20);grid on用圖形表示連續(xù)函數(shù)對連續(xù)函數(shù)進行離散化。基本方法：采樣。采樣密度?？梢暬囊话悴襟E繪制二維圖形繪制三維圖形實驗內(nèi)容：繪制二維圖形數(shù)據(jù)準備選定圖形窗或子圖位置調(diào)用繪圖指令設(shè)置顯示值范圍、刻度和坐標分格線圖形注釋圖形的精細修飾數(shù)據(jù)準備產(chǎn)生自變量的采樣向量及定義域；計算相應(yīng)的函數(shù)值，相應(yīng)得到值域。matlab：t = pi*(0:100)/100;y = sin(t).*sin(9*t);選定圖形窗及子圖位置缺省

2、窗口用指令打開指定圖形窗口和子圖號matlab：figure(1);subplot(2,2,3);調(diào)用繪圖指令線型色彩數(shù)據(jù)點matlab：plot(t,y,b-)線型符號：.含義實線虛線點劃線雙劃線色彩符號bgrcmykw含義藍綠紅青品紅黃黑白數(shù)據(jù)點符號含義符號含義.實心黑點d菱形符diamond+十字符h六角星符hexagram*八線符o空心圓圈朝上三角符p五角星符pentagram朝右三角符x叉字符v朝下三角符設(shè)置顯示值范圍、刻度和坐標分格線matlab：axis(0,pi,-1,1);grid on;常用坐標指令（一）坐標軸控制方式、取向和范圍指令含義axis auto使用缺省設(shè)置axi

3、s manual當前坐標軸范圍不變axis on使用軸背景axis off取消軸背景axis ij矩陣式坐標axis xy普通直角坐標axis(v)v=x1,x2,y1,y2手工設(shè)定坐標范圍常用坐標指令（二）坐標軸的高寬比指令含義axis equal縱橫軸等刻度axis fillmanual下使坐標充滿繪圖區(qū)axis image縱橫軸等刻度，坐標框緊貼數(shù)據(jù)范圍axis normal缺省矩形坐標系axis square產(chǎn)生正方形坐標系axis tight把數(shù)據(jù)范圍直接設(shè)為數(shù)據(jù)范圍圖形注釋matlab:title(調(diào)制波形);xlabel(t); ylabel(y);legend(sin(t),s

4、in(t)sin(9t);text(2,0.5,y=sin(t)sin(9t);圖形的精細修飾matlab:set(h,MarkerSize,10);疊繪t = 2*pi*(0:20)/20;y = cos(t).*exp(-0.4*t);stem(t,y,g);hold on;stairs(t,y,r);hold off;實驗內(nèi)容：繪制三維圖形三維數(shù)據(jù)準備：曲線和曲面選定圖形窗及子圖位置設(shè)置顯示值范圍、刻度和坐標分格線圖形注釋著色、明暗、燈光和材質(zhì)處理視點、三度（縱橫高）比繪制三維曲線matlab:t = pi*(0:0.02:2);x = sin(t); y=cos(t); z = cos

5、(2*t);plot3(x,y,z,b-,x,y,z,bd);view(-82,58), box on, legend(鏈,寶石);繪制三維曲面matlab:x = -10:0.1:10;y = -10:0.1:10;X,Y = meshgrid(x,y);Z = X.2+Y.2;mesh(Z);基本三維繪圖指令曲線：plot3曲面：meshsurfstem3n = 0:0.1:12;y = 1./abs(n+eps-6);h = plot(n,y,r*,MarkerSize,20);grid on title(調(diào)制波形);xlabel(t); ylabel(y);legend(sin(t)s

6、in(9t);text(2,0.5,y=sin(t)sin(9t); set(h,MarkerSize,10);t = 2*pi*(0:20)/20;y = cos(t).*exp(-0.4*t);stem(t,y,g);hold on;stairs(t,y,r);hold off;t = pi*(0:0.02:2);x = sin(t); y=cos(t); z = cos(2*t);plot3(x,y,z,b-,x,y,z,bd);view(-82,58), box on, legend(鏈,寶石);x = -10:0.1:10;y = -10:0.1:10; X,Y = meshgrid

7、(x,y);Z = X.2+Y.2;mesh(Z);三維圖形效果透視鏤空裁剪透 視X0,Y0,Z0 = sphere(30);mesh(X0,Y0,Z0);shading interphidden offaxis equal, axis off鏤 空t = linspace(0,2*pi,100); r = 1-exp(-t/2).*cos(4*t);x,y,z = cylinder(r,60);ii = find(x0);z(ii) = NaN;surf(x,y,z); colormap(spring); shading interp裁 剪x = -8:0.05:8; y = x; X,Y

8、= meshgrid(x,y); ZZ = X.2-Y.2;ii = find(abs(X)6|abs(Y)6);ZZ(ii) = zeros(size(ii);surf(X,Y,ZZ), shading interp; colormap(copper)特殊圖形指令面域圖 area直方圖 bar barh bar3 bar3h餅圖 pie pie3填色圖 fill fill3面域圖 areax = -2:2y = 3,5,2,4,1;3,4,5,2,1;5,4,3,2,5cum_sum = cumsum(y);area(x,y,0)legend(因素A,因素B,因素C),grid on,col

9、ormap(spring)直方圖 bar barhx = -2:2y = 3,5,2,4,1;3,4,5,2,1;5,4,3,2,5subplot(1,2,1),bar(x,y,stacked)xlabel(x), ylabel(Sigma y), colormap(cool) legend(因素A,因素B,因素C)subplot(1,2,2), barh(x,y,grouped)xlabel(y), ylabel(x)legend(因素A,因素B,因素C)直方圖 bar3 bar3hsubplot(1,2,1), bar3(x,y,1)xlabel(因素ABC), ylabel(x),zla

10、bel(y)colormap(summer)subplot(1,2,2), bar3h(x,y,grouped)ylabel(y), zlabel(x)餅圖 pie pie3a = 1,1.6,1.2,0.8,2.1;subplot(1,2,1), pie(a,1 0 1 0 0),legend(1,2,3,4,5);subplot(1,2,2), pie3(a),colormap(cool)填色圖 fill n = 10;dt = 2*pi/n; t = 0:dt:2*pi;t = t,t(1);x = sin(t); y = cos(t);fill(x,y,c); axis offgtext(十邊行);填色圖 fill3xc = ones(2,4)/2;x = xc;0 1 1 0;y = xc;0 0 1 1;z = 1 1 1 1;0 0 0 0;0 0 0 0;c = 1