GUI derivative calculator, issues with coding portion

2 次查看（过去 30 天）
William Fantin
William Fantin 2019-5-6
评论： Murugan C 2019-5-8
Hello All,
I am trying to do my final MATLAB project and it involves creating a GUI that can handle second order differential equations. Firstl I have been trying to figure out how to make a simple derivative GUI calculator, one that can handle something from the user say 4X and when a button is pushed will spit out its derivite, 4. So far I have made the GUI and have been trying to add some code. I am new to MATLAB and some of the errors are confusing. I will post parts of the code along with my logic below:
let me define some things to make it easier to understand.
I have an edit text box whose tag line is FCN (this is the box the user will enter the derivative that needs to be taken)
I have a push button whose tag line is equal
I have a static text box whose tag line is first (this is where the answer will pop out)
I wrote a few lines of code under the equal callback:
function equalPushButton_Callback(hObject, eventdata, handles)
% hObject handle to equalPushButton (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
syms x
a=get(handles.FCN,'string'));
b=str2sym(diff(a)); %Or b=double(b)?
set(handles.first,'string',sym2num(b));
I am wondering if someone can steer me in the right direction
Thanks
  3 个评论
显示 1更早的评论
William Fantin
William Fantin 2019-5-7
Sure, so i did some more research and now my code is different. I have my program where if I type in x it will give the derivative of 1. But when I type say 4*x it will give an error. Heres the code:
function varargout = Test5(varargin)
% TEST5 MATLAB code for Test5.fig
% TEST5, by itself, creates a new TEST5 or raises the existing
% singleton*.
%
% H = TEST5 returns the handle to a new TEST5 or the handle to
% the existing singleton*.
%
% TEST5('CALLBACK',hObject,eventData,handles,...) calls the local
% function named CALLBACK in TEST5.M with the given input arguments.
%
% TEST5('Property','Value',...) creates a new TEST5 or raises the
% existing singleton*. Starting from the left, property value pairs are
% applied to the GUI before Test5_OpeningFcn gets called. An
% unrecognized property name or invalid value makes property application
% stop. All inputs are passed to Test5_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 Test5
% Last Modified by GUIDE v2.5 05-May-2019 12:47:09
% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name', mfilename, ...
'gui_Singleton', gui_Singleton, ...
'gui_OpeningFcn', @Test5_OpeningFcn, ...
'gui_OutputFcn', @Test5_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 Test5 is made visible.
function Test5_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 Test5 (see VARARGIN)
% Choose default command line output for Test5
handles.output = hObject;
% Update handles structure
guidata(hObject, handles);
% UIWAIT makes Test5 wait for user response (see UIRESUME)
% uiwait(handles.figure1);
% --- Outputs from this function are returned to the command line.
function varargout = Test5_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;
function FCN_Callback(hObject, eventdata, handles)
% hObject handle to FCN (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% Hints: get(hObject,'String') returns contents of FCN as text
% str2double(get(hObject,'String')) returns contents of FCN as a double
% --- Executes during object creation, after setting all properties.
function FCN_CreateFcn(hObject, eventdata, handles)
% hObject handle to FCN (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles empty - handles not created until after all CreateFcns called
% Hint: edit 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 equalPushButton.
function equalPushButton_Callback(hObject, eventdata, handles)
% hObject handle to equalPushButton (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
f=get(handles.FCN,'String')'
syms x
der=diff(f,x)
set(handles.first,'String',char(der));
Thanks!!
Murugan C
Murugan C 2019-5-8
Hi
I think, we shouldn't use "syms" for derivative .we have create one more edit box for getting derivative as like below,
f = get(handles.FCN,'String');
x = str2double(get(handles.derivative,'String')); % derivative order
der=diff(f,x);
set(handles.first,'String',char(der));

请先登录，再进行评论。

请先登录，再回答此问题。

回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Data Type Identification 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by