Converting double to a handle

Question

DARLINGTON ETAJE 2020-4-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/520210-converting-double-to-a-handle

评论： Adam Danz 2022-11-28

采纳的回答： Adam Danz

在 MATLAB Online 中打开

When I run the app designer, I keep getting the error

Error setting property 'EditField' of class 'Name0fGui':

Cannot convert double value 2 to a handle

Here is the code

properties (Access = private)
        counter1=0 % Description
        counter2=0 % Description
    end
    
 
    % Callbacks that handle component events
    methods (Access = private)
 
        % Button pushed function: Button
        function ButtonPushed(app, event)
            value1=app.ChestPainCheckBox.Value;
            if value1==1
                app.counter1=app.counter1+1;
            else
                app.counter1=app.counter1;
            end
            value2=app.LuckyDipMaCheckBox.Value;
            if value2==1
                app.counter2=app.counter2+1;
            else
                app.counter2=app.counter2;
            end
            value3=app.AbrosyeCheckBox.Value;
            if value3==1
                app.counter1=app.counter1+1;
            else
                app.counter1=app.counter1;
            end
            value4=app.UnclemidadaCheckBox.Value;
            if value4==1
                app.counter2=app.counter2+1;
            else
                app.counter2=app.counter2;
            end
            app.EditField=app.counter1;
            app.EditField2=app.counter2;
        end
    end

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Maria Paula 2022-11-28

编辑：Adam Danz 2022-11-28

在 MATLAB Online 中打开

When I run the app designer, I keep getting the error

Cannot convert double value NaN to a handle

Here is the code

classdef MetodoBiseccion < matlab.apps.AppBase
    % Properties that correspond to app components
    properties (Access = public)
        UIFigure                      matlab.ui.Figure
        RaizAproximadaEditField       matlab.ui.control.EditField
        RaizAproximadaEditFieldLabel  matlab.ui.control.Label
        MetodoBiseccionLabel          matlab.ui.control.Label
        Calcular                      matlab.ui.control.Button
        tol                           matlab.ui.control.NumericEditField
        ToleranciaEditFieldLabel      matlab.ui.control.Label
        b                             matlab.ui.control.NumericEditField
        ValordebLabel                 matlab.ui.control.Label
        Funcion                       matlab.ui.control.EditField
        FuncionEditFieldLabel         matlab.ui.control.Label
        a                             matlab.ui.control.NumericEditField
        ValordeaLabel                 matlab.ui.control.Label
        UIAxes                        matlab.ui.control.UIAxes
    end
    
    methods (Access = private)
  
    end
    
    methods (Access = public)
        
    end
    
    % Callbacks that handle component events
    methods (Access = private)
        % Button pushed function: Calcular
        function CalcularButtonPushed(app, event)
 
        i=app.a.Value;
        y=app.Funcion.Value(i);
        y(i);
        app.a(i);
        app.b(i); 
        if(str2double(app.Funcion.Value(app.a.Value))*str2double(app.Funcion.Value(app.b.Value))>0) 
            error('Nose cumple el Teorema del Valor Intermedio');
        end
        fa(i)=str2double(app.Funcion.Value(app.a.Value(i)));
        fb(i)=str2double(app.Funcion.Value(app.b.Value(i)));
        
        while(abs(app.b.Value-app.a.Value)>app.tol.Value) 
        if (fa(i)*fb(i)==0)
            if (fa(i))==0
               y(i)=app.a(i);
            break
            end
            else
             y(i)=(app.a.Value(i)+app.b.Value(i))/2; 
             fp(i)=str2double(app.Funcion.Value(num2str(y(i))));
             
         end
        if(fa(i)*fp(i)>0) 
        app.a(i+1)=y(i); 
        app.b(i+1)=app.b(i);
        fa(i+1)=fp(i);
        fb(i+1)=fb(i);
        i=i+1;
        else
        app.a(i+1)=app.a(i);
        app.b(i+1)=str2double(y(i)); % ERROR> Cannot convert double value NaN to a handle
        fa(i+1)=fa(i);
        fb(i+1)=fp(i);
        i=i+1;
        end
        end
        fprintf('  N       a         f(a)          b          f(b)          p           f(p)\n')
        N=length(y);
        for i= 1:N
        fprintf('%4.1f %11.6f %11.6f %11.6f %11.6f %11.6f %11.6f\n',i,app.a(i),fa(i),app.b(i),fb(i),y(i),fp(i))
        end
        end
        % Value changed function: Funcion
        function FuncionValueChanged(app, event)
   
        end
    end

Adam Danz 2022-11-28

@Maria Paula

There are a few lines of your code that looks like this

app.a(i+1)=y(i);

app.a is an object handle but you are trying to assign a value to the handle instead of assigning the value to the object's property. You probably mean app.a.Value(i) = y(i); There is >1 line of code that needs fixed so look carefully.

Also, this looks fishy for the same reason:

app.b(i+1)=app.b(i);

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Answer 1

Adam Danz 2020-4-23

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/520210-converting-double-to-a-handle#answer_427964

在 MATLAB Online 中打开

Try

app.EditField.Value = app.counter1;
app.EditField2.Value = app.counter2;
%             ^^^^^^

If that doesn't fix the problem, please provide the entire error message and point to the line that is causing the error.

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DARLINGTON ETAJE 2020-4-24

Thank you Adam...you are a life saver...I celebrate you. When the isolation is over...please visit Calgary so I can bring you over for dinner with my family...