Matlab_2画图.doc

第二章 Matlab的数据显示Matlab受人欢迎的第一个原因是能直接处理矩阵，第二个，就是画曲线方便。Matlab的图线，是输出到下面命令所激活的图形窗口。相应的命令为：figure(Position,left,bottom,width,height) 产生上面两个窗口的一组命令如下：bdwidth = 5; % 窗口的边的厚度 5 pixels topbdwidth = 30; % 窗口的标题栏高度 30 pixelsset(0,Units,pixels); % 确保单位为 pixels scnsize = get(0,ScreenSize);% 获取屏幕尺寸% 设置绘图窗口的尺寸和位置pos1 = bdwidth+100,. % left1/3*scnsize(4) + bdwidth,. % bottomscnsize(3)/2 - 2*bdwidth,. % Wscnsize(4)/3 - (topbdwidth + bdwidth);% Hpos2 = pos1(1) + 50,. % leftpos1(2)-50, pos1(3), pos1(4); % bottom % W,H% 创建绘图窗口h1=figure(Position,pos1)h2=figure(Position,pos2)绘图工作：画线+图线修饰+加注；1.曲线（2D）画曲线的主要步骤：（1）准备好一组数据：x,y（2）画出其曲线：plot(x,y)如果函数已知： y=f(x)（1）先产生数据 ：x,y；（2）再画图 ：plot(x,y)例1：例2：plot函数中，可以改变线型、线宽、颜色以及数据点的标志等。比如曲线的形式plot(x,y,s); s 为下列字母组合，比如：go颜色类型b blue g green r red c cyan m magenta y yellow k black . point o circle x x-mark + plus * star s square d diamond v triangle (down) triangle (up) triangle (right) p pentagram h hexagram- solid: dotted -. dashdot - dashed (none) no lineaxes 创建新轴；title, xlabel, ylabel, legend title(text) ; xlabel() ylable() legend()get/set 检查和设置特征； set(h,PropertyName,V ) v = get(h,PropertyName)gcf - 当前窗口句柄；gca - 当前坐标系句柄； 加注数轴x = -pi:.1:pi;y = sin(x);plot(x,y)set(gca,XTick,-pi:pi/2:pi)set(gca,XTickLabel,-pi,-pi/2,0,pi/2,pi)xlabel(-pi leq Theta leq pi)ylabel(sin(Theta)title(Plot of sin(Theta)text(-pi/4,sin(-pi/4),leftarrow sin(-pidiv4),.HorizontalAlignment,left) set(findobj(gca,Type,line,Color,0 0 1),.Color,0.5,0,0.5,LineWidth,2)grid onaxis square 加线hold on;y=cos(x);plot(x,y);hold off;颜色RGB定义：TeX字母:曲线修改的图形方式 除了plot, Matlab还有其它常见曲线函数可用数据：x=2*pi*(0:20)/20; y=cos(x).*exp(-0.4*x); plot(x,y,*)feather(x,y) stem(x,y,g) stairs(x,y,r)bar(x,y)直方图（bar，bar3，barh）Y = .5 2 1; 8 7 3; 9 8 6; 5 5 5; 4 3 2;bar(Y)bar3(Y)bar(Y,stack)bar3(Y,group)barh(Y,stack)分类对比图temp = 29 23 27 25 20 23 23 27;days = 0:5:35;bar(days, temp);temp = 29 23 27 25 20 23 23 27;days = 0:5:35;bar(days,temp);xlabel(Day)ylabel(Temperature (oC)temp = 29 23 27 25 20 23 23 27;days = 0:5:35;bar(days,temp)xlabel(Day)ylabel(Temperature (oC)set(gca,YLim,15 30,Layer,top)TCE = 515 420 370 250 135 120 60 20;h1 = gca; h2 = axes(Position,get(h1,Position);plot(days,TCE,Color,y,LineWidth,3);set(h2,YAxisLocation,right,Color,none,XTickLabel,); set(h2,XLim,get(h1,XLim),Layer,top);text(11,380,Concentration,Rotation,-55,FontSize,16,color,r); ylabel(TCE Concentration (PPM);title(Bioremediation,FontSize,16);% To print what you see,set(gcf,PaperPositionMode,auto);百分比图Y = 5 1 2; 8 3 7; 9 6 8; 5 5 5; 4 2 3;area(Y)pie(Y)pie(Y(:,1)pie(Y(:,1),0 0 1 0 0); legend(1,2,3,4,5);Pie3(Y(:,1),0 0 1 0 0);legend(1,2,3,4,5);area(X,Y) 与plot(X,Y, B)相仿，差别在于Y与B之间有填充.Y = 1, 5, 3; 3, 2, 7; 1, 5, 3; 2, 6, 1;area(Y)grid oncolormap summerset(gca,Layer,top)title Stacked Area PlotY(3,1) = -1; % Was 1h = area(Y);set(gca,Layer,top)grid oncolormap summert = (1/16:1/8:1)*2*pi;x = sin(t);y = cos(t);fill(x,y,r)axis square 画曲线簇先确定数组，再画图th=0:pi/50:2*pi;a=0.5:.5:4.5;X=cos(th)*a;Y=sin(th)*sqrt(25-a.2);plot(X,Y);xlabel(x),ylabel(y);加标题： title(Figure);set(gca,Title,text(Interpreter,latex,String,.$fracx2a2+fracy2b2=1$);加注文字： text(x0,y0, text); (x0,y0)为曲线坐标系内的位置text(Interpreter,latex,String,$fracx2a2+fracy2b2=1$,Color,r,Position,3,3)加轴： axis(x1,x2, y1, y2); axis(-Inf,Inf,-Inf,Inf)图例： legend(y );legend(x2/a2+y2/b2=1)axis tight axis equal axis equal数据y为 矩阵 时，每一列代表一根曲线注意x与y的行数相同Z=peaks; plot(Z);t=(0:pi/50:2*pi);k=0/4:0.1:1;Y=cos(t)*k;plot(t,Y)数据为复数：Zplot(eig(randn(20,20),o,MarkerSize,6)双坐标：plotyy(x1,y1,x2,y2)t = 0:pi/20:2*pi;y = exp(sin(t);plotyy(t,y,t,y,plot,stem);t = 0:900; A = 1000; a = 0.005; b = 0.005;z1 = A*exp(-a*t);z2 = sin(b*t);haxes,hline1,hline2 .=plotyy(t,z1,t,z2,semilogy,plot);axes(haxes(1);ylabel(Semilog Plot);axes(haxes(2)ylabel(Linear Plot)x,y = meshgrid(-2:.2:2,-1:.15:1); z = x .* exp(-x.2 - y.2); px,py = gradient(z,.2,.15); contour(x,y,z), hold on quiver(x,y,px,py)； hold off, axis image x,y = meshgrid(-2:.2:2,-1:.15:1); z = x .* exp(-x.2 - y.2); u,v,w = surfnorm(x,y,z); quiver3(x,y,z,u,v,w); hold on, surf(x,y,z), hold offZ = eig(randn(20,20); compass(Z)theta = 2*pi*rand(1,50); rose(theta)hist(theta)x,y = meshgrid(-3:.5:3,-3:.1:3);z = peaks(x,y);ribbon(y,z); %width=0.75colormap hsvload clownsurface(peaks,flipud(X),. FaceColor,texturemap, EdgeColor,none,. CDataMapping,direct); colormap(map)view(-35,45)一个窗口显示多张曲线图: subplot(m,n,p); plot(x,y);总计分为m行n列的窗口，目前在第p个窗口中画图。t = 0:pi/20:2*pi;x,y = meshgrid(t);subplot(2,2,1)plot(sin(t),cos(t)axis equal subplot(2,2,2)z = sin(x)+cos(y);plot(t,z)axis(0 2*pi -2 2)subplot(2,2,3)z = sin(x).*cos(y);plot(t,z)axis(0 2*pi -1 1)subplot(2,2,4)z = (sin(x).2)-(cos(y).2);plot(t,z)axis(0 2*pi -1 1)2.曲面（3D）视角: view(Azimuth, Elevation)数据产生方法： X,Y = meshgrid(x1:dx:x2, y1:dy:y2)X,Y = meshgrid(x1:dx:x2)X,Y,Z = meshgrid(x1:dx:x2,y1:dy:y2,z1:dz:z2)画图：plot3(X,Y,Z,S)这里X, Y和Z是向量或矩阵，S是可选字符串，用来指定颜色、标记符号和线形。其它函数： mesh, surf, patch增加曲面效果：light，alpha, colormap,view, axis三维螺旋线t=0:pi/50:10*pi;plot3(sin(t),cos(t),t);title(Helix),xlabel(sint(t),ylabel(cos(t),zlabel(t);text(0,0,0, Origin);grid;X,Y = meshgrid(-2:0.1:2);Z = X.*exp(-X.2-Y.2);plot3(X,Y,Z)grid onset(0,DefaultAxesColorOrder,1 0 0;0 1 0;0 0 1,DefaultAxesLineStyleOrder,-|-|:)t = 0:pi/20:2*pi; a = ones(length(t),9);for i = 1:9a(:,i) = sin(t-i/5);endplot(t,a)X,Y,Z = peaks(30);surfc(X,Y,Z)colormap hsvaxis(-3 3 -3 3 -10 5)pausek = 5;n = 2k-1;x,y,z = sphere(n);c = hadamard(2k);surf(x,y,z,c);colormap(1 1 0; 0 1 1)axis equal让图线更漂亮:打光(light)，上色(colormap)，透明(alpha)h = surf(peaks);set(h,FaceLighting,phong,FaceColor,interp,. AmbientStrength,0.5)light(Position,1 0 0,Style,infinite);x y z v = flow;p = patch(isosurface(x,y,z,v,-3);isonormals(x,y,z,v,p);set(p,facecolor,red,edgecolor,none);daspect(1 1 1); view(3); axis tight; grid on;camlight; lighting gouraud;alpha(.5);注意：仅仅以下三种图可以透明处理Image Patch Surfacex,y = meshgrid(-2:.2:2);z = x.*exp(-x.2-y.2);surf(x,y,z,gradient(z); axis tightx,y = meshgrid(-2:.2:2);z = x.*exp(-x.2-y.2);surf(x,y,z,FaceAlpha,flat,. AlphaDataMapping,scaled,. AlphaData,gradient(z),. FaceColor,blue); axis tightx,y,z = meshgrid(-1.25:.1:-.25,-2:.2:2,-2:.1:2);v = x.*exp(-x.2-y.2-z.2); h = slice(x,y,z,v,-1 -.75 -.5,0);alpha(color)set(h,EdgeColor,none,FaceColor,interp, FaceAlpha,interp);alphamap(rampdown);alphamap(increase,.1)colormap(hsv);X,Y = meshgrid(-8:.5:8);R = sqrt(X.2 + Y.2) + eps;Z = sin(R)./R;mesh(X,Y,Z)-hidden offX,Y = meshgrid(-8:.5:8);R = sqrt(X.2 + Y.2) + eps;Z = sin(R)./R;mesh(X,Y,Z);surf(X,Y,Z,FaceColor,interp,.EdgeColor,none,FaceLighting,phong)daspect(5 5 1);axis tight; view(-50,30); camlight leftslicex,y,z = meshgrid(-2:.2:2,-2:.25:2,-2:.16:2);v = x.*exp(-x.2-y.2-z.2);xslice = -1.2,.8,2; yslice = 2; zslice = -2,0;slice(x,y,z,v,xslice,yslice,zslice)colormap hsvx,y = meshgrid(-2:.2:2);Z = x.*exp(-x.2-y.2);surf(x,y,Z,gradient(Z)colorbarP = peaks(40);C = del2(P);surf(P,C)colormap hotP = peaks(40);C = del2(P); %del2 computes the discrete Laplacian of any matrix.surf(P)colormap hotcolormapautumn, bone, colorcube, cool, copper, gray, flag, hot, hsv, jet, lines, pink, prism, spring, summer, white, winter颜色操作brighten, caxis, colormapeditor, colorbar, contrast, hsv2rgb, pcolor, rgb2hsv, rgbplotload flujetimage(X)colormap(jet)Colormap graycolormap colorcubecolormap coolsummerautumnwintercopperhotSpringflaglinesprismpinkbonehsv(256)load spine image(X)colormap bone load earth % Load image data, X, and colormap, mapsphere; h = findobj(Type,surface);hemisphere = ones(257,125), X, ones(257,125);set(h,CData,flipud(hemisphere),FaceColor,texturemap)colormap(map)axis equalview(90 0)set(gca,CameraViewAngleMode,manual)view(65 30)显示局部数据建立变量区域计算函数值X,Y=meshgrid(x1:dx:x2,y1:dy:y2)Z = f(X,Y)在关注的节点(X0,Y0)处：Z0 griddata, interpt1, interp2,interp3Z0=griddata(x,y,z,X0,Y0);Z0=interp2(x,y,z,X0,Y0)常见数据源1）Matlab自带：mri, flow, 其余的数据源，自己找全 rand, peaks, 2）数值计算或者实验结果X,Y = meshgrid(-3:.25:3);Z = peak(X,Y);XI,YI = meshgrid(-3:.125:3);ZI = interp2(X,Y,Z,XI,YI);mesh(X,Y,Z), hold, mesh(XI,YI,ZI+15)hold offaxis(-3 3 -3 3 -5 20)x = rand(100,1)*16 - 8;y = rand(100,1)*16 - 8;r = sqrt(x.2 + y.2) + eps;z = sin(r)./r;xlin = linspace(min(x),max(x),33);ylin = linspace(min(y),max(y),33);X,Y = meshgrid(xlin,ylin);%The key to this process is to use griddata to interpolate the values Z = griddata(x,y,z,X,Y,cubic);mesh(X,Y,Z) %interpolatedaxis tight; hold onplot3(x,y,z,.,MarkerSize,15) %nonuniform常见的数据显示方法 Isosurface, isocaps, isonormals从数据源v里面提取isovalue的等值面，结果可直接供patch画出fv = isosurface(x,y,z, v, isovalue)v是在x,y,z处的函数值从数据源提取边界面处的isovalue等值区域，结果可直接供patch画出fvc = isocaps(x,y,z, v, isovalue)v是在x,y,z处的函数值从数据源v提出节点vertices的法向n = isonormals(x,y,z, v,vertices)vertices 计算节点, v是在x, y, z处的梯度 data = cat(3, 0 .2 0; 0 .3 0; 0 0 0, . .1 .2 0; 0 1 0; .2 .7 0,. 0 .4 .2; .2 .4 0;.1 .1 0); data = interp3(data,3, cubic); subplot(1,2,1) p = patch(isosurface(data, .5), FaceColor, red, EdgeColor, none); view(3); daspect(1 1 1);axis tight camlight; camlight(-80,-10); lighting p; title(Triangle Normals) subplot(1,2,2) p = patch(isosurface(data, .5), FaceColor, red, EdgeColor, none); isonormals(data,p) view(3); daspect(1 1 1); axis tight camlight; camlight(-80,-10); lighting phong; title(Data Normals)load mriD = squeeze(D);D(:,1:60,:) = ;p1 = patch(isosurface(D, 5),FaceColor,red,. EdgeColor,none);p2 = patch(isocaps(D, 5),FaceColor,interp,. EdgeColor,no