MATLAB 操作总结

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如何用命令行保存图片？

1. saveas

  用法：saveas( fig, filename, formattype )

  Example:

    x = [2 4 5 6 7];
    bar(x);
    saveas( gcf, 'Barchart.png' )
    saveas( gcf, 'Barchart', 'epsc' ) % save figure as EPS file

2. print

   用法: print( filename, formattype, formatoptions )

  Example:

    % save figure as image file
    bar(1:10)
    print( 'BarPlot', '-dpng' )
    % copy figure to Clipboard
    plot(1:10)
    print( '-clipboard','dmeta' )
    

    fig = figure;
    plot(1:10);
    print( fig, 'MySaveplot', '-dpng' )

画图控制

用到的重要函数有 gca, gcf, set, text。
在需要的时候请仔细阅读 MATLAB 中 Axes Properties 等相关文档，了解图形控制中可变参数。

函数说明:

• gca  返回当前坐标轴和图形。

    x = -2*pi:0.1:2*pi;
    y = sin(x);
    plot(x,y)
    xlabel('x')
    ylabel('y')
  
    ax = gca;
    ax.XAxisLocation
    ax.YAxisLocation
    ax.XAxisLocation = 'origin'; % setting x axis location to origin
    ax.YAxisLocation = 'origin'; % setting y axis location to origin
    ax.Box = 'off'; % Turn off the display of the axes outline
    ax.Layer = 'top'; % Make grid lines and tick marks appear over graphics objects
  

mf1.jpg

• gcf  返回当前图形的句柄

    surf(peaks)
    fig = gcf;
    fig.Color = [0 0.5 0.5];
    fig.ToolBar = 'none';
  

mf2.jpg

• set  设置图形目标性质

  语法： set(H, Name, Value)

    x = 0:30;
    y = [1.5*cos(x); 4*exp(-.1*x).*cos(x); exp(.05*x).*cos(x)]';
    S = stem(x,y);
    NameArray = {'Marker','Tag'};
    ValueArray = {'o','Decaying Exponential';...
    'square','Growing Exponential';...
    '*','Steady State'};
    set(S,NameArray,ValueArray)
  

mf3.jpg

子图控制

Colorbar控制

Position 参数为 [left bottom width height]

    x=[60:20:260]; %set x axis ticks
    y=rand(11);  %get something to plot
    h1=subplot(2,1,2); %setup subplot1
    plot(x,y,'-.'); %plot subplot1
    box on  %  leave only x and y axes
    xlim([60 260])  %setup some x axis 
    set(h1,'Xtick',x) %set the x axis ticks to show only x
    h1_pos = get(h1,'Position'); %get the position data for sublot1.
    y2 = 10*y.^2;  %make something up for subplot2
    h2=subplot(2,1,1);  %make subplot2
    plot(x,10*y,'-.'); %plot subplot2
    box on
    set(h2,'Xcolor',[1 1 1]) %make the Y axis line white
    set(h2,'Xtick',[])
    xlim([60 260])  %setup some x axis 
    h2_pos=get(h2,'Position'); 
    set(h2,'Position',[h1_pos(1) h1_pos(2)+h1_pos(4) h2_pos(3:end)]) %using position of subplot1 put subplot2next to it.

mf4.jpg

坐标轴控制

1. 坐标轴刻度朝外

   set(gca, 'tickdir', 'out')

2. 坐标轴颜色

   set(gca, 'XColor', 'red')

3. 其它

    set(gca, 'XLim', [min max]);   % range 
    set(gca, 'XTick', [ markerpoint ]);     % markerpoint
    set(gca, 'XTicklabel', {}];     %marker
    set(gca, 'XGrid', 'on');        %grid on
   

防止图缩小后字体过小或发虚

    set(gcf, 'Position', [100 100 260 220]);
    set(gca, 'Position', [.13 .17 .80 .74]);
    figure_Fontsize = 8;
    set(get(gca, 'XLabel'), 'FontSize', figure_Fontsize, 'Vertical', 'top');
    set(get(gca, 'YLabel'), 'FontSize', figure_Fontsize, 'Vertical', 'middle');
    set(findobj('FontSize',10), 'FontSize', figure_Fontsize);
    set(findobj(get(gca, 'Children'), 'LineWidth', 0.5), 'LineWidth', 2);

图形窗口

colordef 定义绘图背景色

随机数生成

可用函数: rand, randi, randn, randperm, randsrc, unifrnd