I've been trying to run my matlab GUI but in the command window appears this error: ''error in untitled (line 42) gui_mainfcn(gui_state varargin )''. The entire code is given below. Any soulution?

function varargout = calculo_tubos_fp(varargin)
% CALCULO_TUBOS_FP MATLAB code for calculo_tubos_fp.fig
%      CALCULO_TUBOS_FP, by itself, creates a new CALCULO_TUBOS_FP or raises the existing
%      singleton*.
%
%      H = CALCULO_TUBOS_FP returns the handle to a new CALCULO_TUBOS_FP or the handle to
%      the existing singleton*.
%
%      CALCULO_TUBOS_FP('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in CALCULO_TUBOS_FP.M with the given input arguments.
%
%      CALCULO_TUBOS_FP('Property','Value',...) creates a new CALCULO_TUBOS_FP or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before calculo_tubos_fp_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to calculo_tubos_fp_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 calculo_tubos_fp

% Last Modified by GUIDE v2.5 28-Dec-2018 12:46:29

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @calculo_tubos_fp_OpeningFcn, ...
                   'gui_OutputFcn',  @calculo_tubos_fp_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 calculo_tubos_fp is made visible.
function calculo_tubos_fp_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 calculo_tubos_fp (see VARARGIN)

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

% Update handles structure
guidata(hObject, handles);

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


% --- Outputs from this function are returned to the command line.
function varargout = calculo_tubos_fp_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 boton_calculos_tubos_Callback(hObject, eventdata, handles) 
 a = get(handles.popupmenu1,'String'); 
 s = get(handles.popupmenu1, 'Value');
 n = a(s);
 l = get(handles.temperatura,'String');
 k = get(handles.presion,'String');
 g = get(handles.Ea,'String');
 m = get(handles.Ko,'String');
 p = get(handles.Xo,'String');
 y = get(handles.Xf,'String');
 q = get(handles.Fexpansion,'String');
 o = get(handles.caudal,'String');
 u = get(handles.diametro,'String');
 v = get(handles.longitud,'String');
 
  % Declaración de variables y convertimos los datos(letras)a numeros
 n1=str2double(n);   
 T=str2double(l);    
 P=str2double(k);   
 Ea=str2double(g);  
 Ko=str2double(m);   
 Xo=str2double(p);  
 Xf=str2double(y);    
 Fe=str2double(q);  
 Vo=str2double(o); 
 D=str2double(u);
 L=str2double(v);
 R=8.314472;        

 % Resolución ecuaciones
 k=Ko*exp(-Ea/(R*T));
 CAo=P/(R*T);
 ra=@(XA) 1./((k.*(CAo.^n1).*((1-XA).^n1))./(1+Fe.*XA).^nl);
 f=integral(ra,Xo,Xf);
 result = ((CAo.*Vo)./((pi./4).*D^.2.*L)).*f;
 
 set(handles.resultado,'String',result);
 
 
 

function boton_atras_tubos_fp_Callback(hObject, eventdata, handles)
close(gcf)
reactor_fp;

function edit1_Callback(hObject, eventdata, handles)


function resultado_CreateFcn(hObject, eventdata, handles)

% 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 popupmenu1_Callback(hObject, eventdata, handles)


function popupmenu1_CreateFcn(hObject, eventdata, handles)

% 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


function temperatura_Callback(hObject, eventdata, handles)


function temperatura_CreateFcn(hObject, eventdata, handles)

% 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 presion_Callback(hObject, eventdata, handles)


function presion_CreateFcn(hObject, eventdata, handles)

% 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 Ea_Callback(hObject, eventdata, handles)


function Ea_CreateFcn(hObject, eventdata, handles)

% 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 Ko_Callback(hObject, eventdata, handles)


function Ko_CreateFcn(hObject, eventdata, handles)

% 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 Xo_Callback(hObject, eventdata, handles)


function Xo_CreateFcn(hObject, eventdata, handles)

% 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 Xf_Callback(hObject, eventdata, handles)


function Xf_CreateFcn(hObject, eventdata, handles)

% 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 Fexpansion_Callback(hObject, eventdata, handles)


function Fexpansion_CreateFcn(hObject, eventdata, handles)

% 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 caudal_Callback(hObject, eventdata, handles)


function caudal_CreateFcn(hObject, eventdata, handles)

% 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 diametro_Callback(hObject, eventdata, handles)


function diametro_CreateFcn(hObject, eventdata, handles)

% 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 longitud_Callback(hObject, eventdata, handles)


function longitud_CreateFcn(hObject, eventdata, handles)

% 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

[Stephen23]

@ Álvaro López Moreno: please delete your code from the question and upload it by clicking the paperclip button. This is because while a small amount of code in a question is fine, having hundreds of lines of code is awkward for everyone.

[Álvaro López Moreno]

Sorry, It's my first time here, do you mean ''insert a line of code''?

[Image Analyst]

How are you running it? By clicking the green run triangle, right? Not by double clicking the .fig file in the current folder panel, right?

Attach both your .m and .fig file with the paper clip icon so we can run it ourselves.

[Álvaro López Moreno]

Greetings Image Analyst, yes of coure, I run it by clicking that triangle. Ok I will attach them:

Answer 1

[Geoff Hayes]

Álvaro - in the future, please copy and paste the full error message to this question AND the steps that lead to this error message. I can launch your GUI without error so you will need to describe what you are doing when the error occurs. However, if I press the Calculos button, I observe the following error

Undefined function or variable 'nl'.

Error in
calculo_tubos_fp>boton_calculos_tubos_Callback/@(XA)1./((k.*(CAo.^n1).*((1-XA).^n1))./(1+Fe.*XA).^nl)



Error in integralCalc/midpArea (line 395)
        fx = f(x);

Error in integralCalc (line 105)
        q = midpArea(FUN,A,B);

Error in integral (line 88)
Q = integralCalc(fun,a,b,opstruct);

Error in calculo_tubos_fp>boton_calculos_tubos_Callback (line 109)
 f=integral(ra,Xo,Xf);

Error in gui_mainfcn (line 95)
        feval(varargin{:});

Error in calculo_tubos_fp (line 42)
    gui_mainfcn(gui_State, varargin{:});

Error in
@(hObject,eventdata)calculo_tubos_fp('boton_calculos_tubos_Callback',hObject,eventdata,guidata(hObject))

 
Error while evaluating uicontrol Callback

The nl is from the line of code

ra=@(XA) 1./((k.*(CAo.^n1).*((1-XA).^n1))./(1+Fe.*XA).^nl);

but nowhere have you defined what nl should be...but you have defined an n and an l so perhaps you mean n*l or something similar. Or should this be n1?

[Álvaro López Moreno]

Thank you for your assistance, the problem was in that variable, so I had to change it and the code can already run.