how to plot an airfoil coordination using Matlab GUI ?

Hi everybody, i was working on a Airfoil generator: Airfoil generation using CST parameterization method i wanted to make an GUI of it, but not having any result, no plotting. can anyone at least let me know where is the problem.

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

% Last Modified by GUIDE v2.5 14-Aug-2016 17:32:10

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

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

% Update handles structure
guidata(hObject, handles);

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

% --- Outputs from this function are returned to the command line.
function varargout = CST_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 a_Callback(hObject, eventdata, handles)
% hObject    handle to a (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 a as text
%        str2double(get(hObject,'String')) returns contents of a as a double

% --- Executes during object creation, after setting all properties.
function a_CreateFcn(hObject, eventdata, handles)
% hObject    handle to a (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 d_Callback(hObject, eventdata, handles)
% hObject    handle to d (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 d as text
%        str2double(get(hObject,'String')) returns contents of d as a double

% --- Executes during object creation, after setting all properties.
function d_CreateFcn(hObject, eventdata, handles)
% hObject    handle to d (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 N_Callback(hObject, eventdata, handles)
% hObject    handle to N (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 N as text
%        str2double(get(hObject,'String')) returns contents of N as a double

% --- Executes during object creation, after setting all properties.
function N_CreateFcn(hObject, eventdata, handles)
% hObject    handle to N (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 dz_Callback(hObject, eventdata, handles)
% hObject    handle to dz (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 dz as text
%        str2double(get(hObject,'String')) returns contents of dz as a double

% --- Executes during object creation, after setting all properties.
function dz_CreateFcn(hObject, eventdata, handles)
% hObject    handle to dz (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 b_Callback(hObject, eventdata, handles)
% hObject    handle to b (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 b as text
%        str2double(get(hObject,'String')) returns contents of b as a double

% --- Executes during object creation, after setting all properties.
function b_CreateFcn(hObject, eventdata, handles)
% hObject    handle to b (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 c_Callback(hObject, eventdata, handles)
% hObject    handle to c (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 c as text
%        str2double(get(hObject,'String')) returns contents of c as a double

% --- Executes during object creation, after setting all properties.
function c_CreateFcn(hObject, eventdata, handles)
% hObject    handle to c (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 e_Callback(hObject, eventdata, handles)
% hObject    handle to e (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 e as text
%        str2double(get(hObject,'String')) returns contents of e as a double

% --- Executes during object creation, after setting all properties.
function e_CreateFcn(hObject, eventdata, handles)
% hObject    handle to e (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 f_Callback(hObject, eventdata, handles)
% hObject    handle to f (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 f as text
%        str2double(get(hObject,'String')) returns contents of f as a double

% --- Executes during object creation, after setting all properties.
function f_CreateFcn(hObject, eventdata, handles)
% hObject    handle to f (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 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)
a = str2num(get(handles.a, 'string'));
b = str2num(get(handles.b, 'string'));
c = str2num(get(handles.c, 'string'));
d = str2num(get(handles.d, 'string'));
e = str2num(get(handles.e, 'string'));
f = str2num(get(handles.f, 'string'));
dz = str2num(get(handles.dz, 'string'));
N = str2num(get(handles.N, 'string'));
wl = [a , b , c];
wu = [d , e , f];
%function [coord] =CST_airfoil(wl,wu,dz,N);
% Description : Create a set of airfoil coordinates using CST parametrization method 
% Input  : wl = CST weight of lower surface
%          wu = CST weight of upper surface
%          dz = trailing edge thickness
% Output : coord = set of x-y coordinates of airfoil generated by CST

% Create x coordinate
x=ones(N+1,1);y=zeros(N+1,1);zeta=zeros(N+1,1);
for i=1:N+1
    zeta(i)=2*pi/N*(i-1);
    x(i)=0.5*(cos(zeta(i))+1);
end

% N1 and N2 parameters (N1 = 0.5 and N2 = 1 for airfoil shape)
N1 = 0.5;
N2 = 1;

zerind = find(x(:,1) == 0); % Used to separate upper and lower surfaces

xl= x(1:zerind-1); % Lower surface x-coordinates
xu = x(zerind:end); % Upper surface x-coordinates

[yl] = ClassShape(wl,xl,N1,N2,-dz); % Call ClassShape function to determine lower surface y-coordinates
[yu] = ClassShape(wu,xu,N1,N2,dz);  % Call ClassShape function to determine upper surface y-coordinates

y = [yl;yu]; % Combine upper and lower y coordinates

coord = [x y]; % Combine x and y into single output

%%Function to calculate class and shape function
function [y] = ClassShape(w,x,N1,N2,dz);

% Class function; taking input of N1 and N2
for i = 1:size(x,1)
    C(i,1) = x(i)^N1*((1-x(i))^N2);
end

% Shape function; using Bernstein Polynomials
n = size(w,2)-1; % Order of Bernstein polynomials

for i = 1:n+1
     K(i) = factorial(n)/(factorial(i-1)*(factorial((n)-(i-1))));
end

for i = 1:size(x,1)
    S(i,1) = 0;
    for j = 1:n+1
        S(i,1) = S(i,1) + w(j)*K(j)*x(i)^(j-1)*((1-x(i))^(n-(j-1)));
    end
end

% Calculate y output
for i = 1:size(x,1)
   y(i,1) = C(i,1)*S(i,1) + x(i)*dz;
end
axes(handles.axes1);
plot(x,y);

Answer 1

[Geoff Hayes]

oussama - I had trouble launching your GUI because you've named the files as CST_GUI yet the GUI (in the code) is named as CST. Please rename your files to CST.m and CST.fig.

Once that has been corrected, you can launch the GUI and enter some data into the edit controls. When the Show Me The Airfoil button is pressed the following error appears

 Undefined variable "handles" or class "handles.axes1".

 Error in CST>ClassShape (line 333)
 axes(handles.axes1);

It seems that you are updating the axes from within the ClassShape function which does not have access to the handles structure. You will need to pass it in as an input parameter which will require you to change the signature to

 function [y] = ClassShape(w,x,N1,N2,dz,handles)

Though this may not be what you want either. As you call ClassShape twice, the second call will overwrite the plot from the first. Is this intended?

[oussama souadka]

Thanks Mr Geoff Hayes for your quick respond :) it's working