如何求解一个将绘制cos（x）的MATLAB脚本的X值范围从＆＃x2013; pi到pi，并以参数更改行宽度？

Question

我正在尝试编写一个MATLAB函数，该功能将使用黑星（*）绘制从–pi到PI的X值的COS（X）。它将在一个图形窗口中进行三次操作，并具有不同的线宽度。

宽度为1、2和3。

（注意：即使绘制了各个点而不是实线，线宽度属性也会改变这些点的大小。）如果没有参数传递给函数，则行 ，一个参数传递给函数，它是这些值的乘数 （例如，如果通过3，则线宽度为3、6和9）。线宽度将在图上的标题中打印出来。

我已经开始进步，通过在一个图中显示三个图，但是当必须传递函数调用的参数时，我不知道该语法如何适合其他条件。我总是以1、2和3的线路宽度的默认值。对您所看到的最佳源代码的任何帮助或重大更改将不胜感激。

function plotCos(varargin)
    
    % Default line widths
    lw1 = 1;
    lw2 = 2;
    lw3 = 3;
    
    % If a random number is passed as an argument
    % Example: If 3 is passed, the line widths will be 3, 6, and 9 
    if nargin == 1
        % Multiply the default line widths with that number
        lw1 = lw1 * varargin{1};
        lw2 = lw2 * varargin{1};
        lw3 = lw3 * varargin{1};
    end
    
    % Create the figure window
    f = figure();
    
    % Set the title
    f.Name = 'Plot of cos(x) from -pi to pi';
    
    % Set the position of the figure window to be in the center of the screen
    f.Position = [100 100 600 400];
    
    % Set the axes
    a1 = subplot(1, 3, 1);
    a2 = subplot(1, 3, 2);
    a3 = subplot(1, 3, 3);
    
    % Set the title of the first plot
    a1.Title.String = sprintf('Line width: %d', lw1);
    
    % Set the title of the second plot
    a2.Title.String = sprintf('Line width: %d', lw2);
    
    % Set the title of the third plot
    a3.Title.String = sprintf('Line width: %d', lw3);
    
    % Set the x and y axes
    a1.XAxis.Label.String = 'x';
    a1.YAxis.Label.String = 'cos(x)';
    a2.XAxis.Label.String = 'x';
    a2.YAxis.Label.String = 'cos(x)';
    a3.XAxis.Label.String = 'x';
    a3.YAxis.Label.String = 'cos(x)';
    
    % Set the x and y limits
    a1.XLim = [-pi, pi];
    a1.YLim = [-1, 1];
    a2.XLim = [-pi, pi];
    a2.YLim = [-1, 1];
    a3.XLim = [-pi, pi];
    a3.YLim = [-1, 1];
    
    % Create an array of values from -pi to pi, in steps of 0.1
    vals = -pi:0.1:pi;
    
    % Plot the cos(x) values with line width lw1
    plot(a1, vals, cos(vals), 'k*', 'LineWidth', lw1);
    
    % Plot the cos(x) values with line width lw2
    plot(a2, vals, cos(vals), 'k*', 'LineWidth', lw2);
    
    % Plot the cos(x) values with line width lw3
    plot(a3, vals, cos(vals), 'k*', 'LineWidth', lw3);
    
    % Set the x and y ticks
    a1.XTick = -pi:pi/2:pi;
    a1.YTick = -1:1;
    a2.XTick = -pi:pi/2:pi;
    a2.YTick = -1:1;
    a3.XTick = -pi:pi/2:pi;
    a3.YTick = -1:1;
    
    % Set the x and y grid lines
    a1.XGrid = 'on';
    a1.YGrid = 'on';
    a2.XGrid = 'on';
    a2.YGrid = 'on';
    a3.XGrid = 'on';
    a3.YGrid = 'on';
    
    % Display the line widths in the titles
    a1.Title.String = sprintf('Line width: %d', lw1);
    a2.Title.String = sprintf('Line width: %d', lw2);
    a3.Title.String = sprintf('Line width: %d', lw3);

    % Set the figure to be visible
    f.Visible = 'on';
    
    % Display the plot
    drawnow
    
    % Save the plot as a png image in the current folder
    saveas(f, 'plotCos.png');
end

单击以查看我的情节的进度