matlab中gui绘制曲线 y=2e-0.5xsin(2πx)，并建立一个与之相联系的快捷菜单，用以控制曲线的线型和曲线宽度。

以下是实现该功能的步骤：

1. 创建一个新的 matlab GUI，可以通过在命令行窗口输入 "guide" 打开 GUI 编辑器来创建。

2. 在 GUI 中添加一个坐标轴（Axes）和一个快捷菜单（uicontextmenu）。

3. 在坐标轴上绘制曲线，可以使用 plot 函数。代码如下：

x = 0:0.01:10;
y = 2*exp(-0.5*x).*sin(2*pi*x);
plot(x,y,'LineWidth',1);

4. 将绘制的曲线与坐标轴关联起来，可以使用 set 函数。代码如下：

h = plot(x,y,'LineWidth',1);
set(h,'Parent',handles.axes1);

5. 在快捷菜单中添加选项，用于控制曲线的线型和曲线宽度。可以使用 uimenu 函数来实现。代码如下：

menu = uicontextmenu(handles.figure1);
uimenu(menu,'Label','线型 - 实线','Callback',@lineStyle_Callback);
uimenu(menu,'Label','线型 - 虚线','Callback',@lineStyle_Callback);
uimenu(menu,'Label','线型 - 点线','Callback',@lineStyle_Callback);
uimenu(menu,'Label','线宽 - 1','Callback',@lineWidth_Callback);
uimenu(menu,'Label','线宽 - 2','Callback',@lineWidth_Callback);
uimenu(menu,'Label','线宽 - 3','Callback',@lineWidth_Callback);
set(handles.axes1,'UIContextMenu',menu);

6. 实现回调函数，控制曲线的线型和曲线宽度。回调函数可以使用 switch 语句来判断用户选择的选项，并使用 set 函数来修改曲线的属性。代码如下：

function lineStyle_Callback(hObject,eventdata)
    handles = guidata(hObject);
    switch get(eventdata,'Label')
        case '线型 - 实线'
            set(handles.plot,'LineStyle','-');
        case '线型 - 虚线'
            set(handles.plot,'LineStyle','--');
        case '线型 - 点线'
            set(handles.plot,'LineStyle',':');
    end
end

function lineWidth_Callback(hObject,eventdata)
    handles = guidata(hObject);
    switch get(eventdata,'Label')
        case '线宽 - 1'
            set(handles.plot,'LineWidth',1);
        case '线宽 - 2'
            set(handles.plot,'LineWidth',2);
        case '线宽 - 3'
            set(handles.plot,'LineWidth',3);
    end
end

完整的 GUI 代码如下：

function varargout = curve_gui(varargin)
% CURVE_GUI MATLAB code for curve_gui.fig
%      CURVE_GUI, by itself, creates a new CURVE_GUI or raises the existing
%      singleton*.
%
%      H = CURVE_GUI returns the handle to a new CURVE_GUI or the handle to
%      the existing singleton*.
%
%      CURVE_GUI('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in CURVE_GUI.M with the given input arguments.
%
%      CURVE_GUI('Property','Value',...) creates a new CURVE_GUI or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before curve_gui_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to curve_gui_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help curve_gui

% Last Modified by GUIDE v2.5 10-Jun-2021 13:57:45

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @curve_gui_OpeningFcn, ...
                   'gui_OutputFcn',  @curve_gui_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before curve_gui is made visible.
function curve_gui_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to curve_gui (see VARARGIN)

% Choose default command line output for curve_gui
handles.output = hObject;

% plot curve
x = 0:0.01:10;
y = 2*exp(-0.5*x).*sin(2*pi*x);
handles.plot = plot(x,y,'LineWidth',1);
set(handles.plot,'Parent',handles.axes1);

% add context menu
menu = uicontextmenu(handles.figure1);
uimenu(menu,'Label','线型 - 实线','Callback',@lineStyle_Callback);
uimenu(menu,'Label','线型 - 虚线','Callback',@lineStyle_Callback);
uimenu(menu,'Label','线型 - 点线','Callback',@lineStyle_Callback);
uimenu(menu,'Label','线宽 - 1','Callback',@lineWidth_Callback);
uimenu(menu,'Label','线宽 - 2','Callback',@lineWidth_Callback);
uimenu(menu,'Label','线宽 - 3','Callback',@lineWidth_Callback);
set(handles.axes1,'UIContextMenu',menu);

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes curve_gui wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = curve_gui_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on selection change in popupmenu1.
function popupmenu1_Callback(hObject, eventdata, handles)
% hObject    handle to popupmenu1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns popupmenu1 contents as cell array
%        contents{get(hObject,'Value')} returns selected item from popupmenu1


% --- Executes during object creation, after setting all properties.
function popupmenu1_CreateFcn(hObject, eventdata, handles)
% hObject    handle to popupmenu1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: popupmenu controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end


% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)


% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)


function lineStyle_Callback(hObject,eventdata)
    handles = guidata(hObject);
    switch get(eventdata,'Label')
        case '线型 - 实线'
            set(handles.plot,'LineStyle','-');
        case '线型 - 虚线'
            set(handles.plot,'LineStyle','--');
        case '线型 - 点线'
            set(handles.plot,'LineStyle',':');
    end
end

function lineWidth_Callback(hObject,eventdata)
    handles = guidata(hObject);
    switch get(eventdata,'Label')
        case '线宽 - 1'
            set(handles.plot,'LineWidth',1);
        case '线宽 - 2'
            set(handles.plot,'LineWidth',2);
        case '线宽 - 3'
            set(handles.plot,'LineWidth',3);
    end
end

运行该 GUI，即可看到绘制的曲线和快捷菜单。在快捷菜单中选择不同的选项，即可控制曲线的线型和曲线宽度。