Question Method Newton-Rhapson

Question

Jessé 2015-7-27

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/231368-question-method-newton-rhapson

回答： Walter Roberson 2015-7-27

function varargout = Interface(varargin)
% Interface MATLAB code for Interface.fig
%      Interface, by itself, creates a new Interface or raises the existing
%      singleton*.
%
%      H = Interface returns the handle to a new Interface or the handle to
%      the existing singleton*.
%
%      Interface('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in Interface.M with the given input arguments.
%
%      Interface('Property','Value',...) creates a new Interface or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before Interface_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to Interface_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 Interface
% Last Modified by GUIDE v2.5 27-Jul-2015 14:54:30
% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @Interface_OpeningFcn, ...
                   'gui_OutputFcn',  @Interface_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
clc
clear all
% End initialization code - DO NOT EDIT
% --- Executes just before Interface is made visible.
function Interface_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 Interface (see VARARGIN)
% Choose default command line output for Interface
handles.output = hObject;
% Update handles structure
guidata(hObject, handles);
% UIWAIT makes Interface wait for user response (see UIRESUME)
% uiwait(handles.figure1);
% --- Outputs from this function are returned to the command line.
function varargout = Interface_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 button press in cmdCalcular.
function cmdCalcular_Callback(hObject, eventdata, handles)
% hObject    handle to cmdCalcular (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
%manejo de excepciones con try y catch
try
%Declaracion de variables. Se declara X como variable simbolica para poder utilizarla dentro de una funcion
%y no solo como cadena de texto
funcion=get(handles.txtFuncion,'string');
x0=str2double(get(handles.txtX0,'string'));
porcentajeError=str2double(get(handles.txtPorcentajeError,'string'));
syms x
iteracion=0;
errorCalculado=100;
f=sym(funcion);
derivada=diff(f,x);
%limpar tabla antes de mostrar resultado
set(handles.tabla,'Data',{})
%Comprobando que la derivada no sea cero.Casocontrario mostrar un mensaje
%que no hay raiz p.e se ingreso uan constante en lugar de una funcion de x
if derivada==0
    %limpar tabla, grafico en caso de que antes se haya graficado uan
    %funcion
      hold off
      cla
      set(handles.tabla,'Data',{})
      set(handles.txtRaiz,'string','Nao existe raiz neste intervalo');
else
%Iteraciones sucesivas para una mejor aproximacion de la raiz por el metodo
%N-R
while errorCalculado>porcentajeError
    fx=subs(f,x0);
    dx=subs(derivada,x0);
    x1=x0-(fx/dx);
    errorCalculado=abs(((x1-x0)/x1)*100);
     %mostrara datos en tabla
    valores = {iteracion x0 x1 errorCalculado}; 
    temp=get(handles.tabla,'data');
    valoresNuevos=[valores;temp];
    set(handles.tabla,'Data',valoresNuevos)
    x0=x1;
    iteracion=iteracion+1;
end
%Mostrando respuesta en textbox con formato coma flotante a 16 cifras decimales
    respuesta=sprintf('%0.16f',x1);
    set(handles.txtRaiz,'string',respuesta);
%Grafica de la funcion
hold off
handles.axes1=ezplot(f);
grid on;
hold on;
handles.axes1=plot(x1,subs(f,respuesta),'r*');
zoom on
end
catch 
        msgbox('Ocorreu um erro! Verifique se introduziu os dados corretamente e de forma adequada!','Error','error')
end
% --- Executes on button press in cmdlimpar.
function cmdLimpar_Callback(hObject, eventdata, handles)
% hObject    handle to cmdLimpar (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
%limpar area de grafico
cla
%limpar tabla
set(handles.tabla,'Data',{})
%limpar textboxs
set(handles.txtFuncion,'string','');
set(handles.txtX0,'string','');
set(handles.txtPorcentajeError,'string','');
set(handles.txtRaiz,'string','');
function txtFuncion_Callback(hObject, eventdata, handles)
% hObject    handle to txtFuncion (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 txtFuncion as text
%        str2double(get(hObject,'String')) returns contents of txtFuncion as a double
% --- Executes during object creation, after setting all properties.
function txtFuncion_CreateFcn(hObject, eventdata, handles)
% hObject    handle to txtFuncion (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
function txtX0_Callback(hObject, eventdata, handles)
% hObject    handle to txtX0 (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 txtX0 as text
%        str2double(get(hObject,'String')) returns contents of txtX0 as a double
% --- Executes during object creation, after setting all properties.
function txtX0_CreateFcn(hObject, eventdata, handles)
% hObject    handle to txtX0 (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
function txtPorcentajeError_Callback(hObject, eventdata, handles)
% hObject    handle to txtPorcentajeError (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 txtPorcentajeError as text
%        str2double(get(hObject,'String')) returns contents of txtPorcentajeError as a double
% --- Executes during object creation, after setting all properties.
function txtPorcentajeError_CreateFcn(hObject, eventdata, handles)
% hObject    handle to txtPorcentajeError (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
function txtRaiz_Callback(hObject, eventdata, handles)
% hObject    handle to txtRaiz (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 txtRaiz as text
%        str2double(get(hObject,'String')) returns contents of txtRaiz as a double
% --- Executes during object creation, after setting all properties.
function txtRaiz_CreateFcn(hObject, eventdata, handles)
% hObject    handle to txtRaiz (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
% --------------------------------------------------------------------
function sobre_Callback(hObject, eventdata, handles)
% hObject    handle to sobre (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
sair
% --------------------------------------------------------------------
function instrucoes_Callback(hObject, eventdata, handles)
% hObject    handle to instrucoes (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
instrucoes
% --------------------------------------------------------------------
function sair_Callback(hObject, eventdata, handles)
% hObject    handle to sair (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
close