function varargout = IIRbu(varargin)
% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @IIRbu_OpeningFcn, ...
                   'gui_OutputFcn',  @IIRbu_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin & isstr(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

function IIRbu_OpeningFcn(hObject, eventdata, handles, varargin)
handles.output = hObject;
guidata(hObject, handles);
function varargout = IIRbu_OutputFcn(hObject, eventdata, handles)
varargout{1} = handles.output;
function edit1_CreateFcn(hObject, eventdata, handles)

if ispc
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end
function edit1_Callback(hObject, eventdata, handles)
N = str2num(get(hObject, 'String'));
data = getappdata(gcbf, 'UserData');
data.N = N;
setappdata(gcbf, 'UserData', data);
function edit2_CreateFcn(hObject, eventdata, handles)

if ispc
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end
function edit2_Callback(hObject, eventdata, handles)
W1= str2num(get(hObject, 'String'));
data = getappdata(gcbf, 'UserData');
data.W1 = W1;
setappdata(gcbf, 'UserData', data);

function edit4_CreateFcn(hObject, eventdata, handles)
if ispc
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end

function edit4_Callback(hObject, eventdata, handles)
W2 = str2num(get(hObject, 'String'));
data = getappdata(gcbf, 'UserData');
data.W2 = W2;
setappdata(gcbf, 'UserData', data);

function pushbutton1_Callback(hObject, eventdata, handles)
data = getappdata(gcbf, 'UserData');
M=data.N/2;
Wn=[data.W1 data.W2]
[b,a] = butter(M,Wn);
disp(b)
disp(a)
w= 0:0.01/pi:pi;
h = freqz(b,a,w);
gain = 20*log10(abs(h));
plot (w/pi,gain);grid;
xlabel('Normalized frequency'); ylabel('Gain, dB');

function pushbutton2_Callback(hObject, eventdata, handles)
data = getappdata(gcbf, 'UserData');
M=data.N/2;
Wn=[data.W1 data.W2]
[b,a] = butter(M,Wn);
set(handles.listbox1, 'String', b);

function pushbutton3_Callback(hObject, eventdata, handles)
data = getappdata(gcbf, 'UserData');
M=data.N/2;
Wn=[data.W1 data.W2]
[b,a] = butter(M,Wn);
set(handles.listbox2, 'String', a);

function listbox1_CreateFcn(hObject, eventdata, handles)

if ispc
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end
function listbox1_Callback(hObject, eventdata, handles)

function listbox2_CreateFcn(hObject, eventdata, handles)

if ispc
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end

function listbox2_Callback(hObject, eventdata, handles)
