A short intermission about function handles and cell arrays

A short intermission about function handles and cell arrays

A MATLAB function may be referenced by a handle.

>> sphere(100)

A short intermission about function handles and cell arrays

A MATLAB function may be referenced by a handle.

s = @sphere

[XX YY ZZ] = feval(s,100)

Example

function draw(function_handle, function_parameter)

[XX YY ZZ] = feval(function_handle, function_parameter);

surf_handle = surf(XX,YY,ZZ);

ax = get(surf_handle,'parent');

shading(ax,'INTERP')

What would be the result of: draw(s,100) ? draw(@cylinder,100) ?

Cell arrays are similar to normal arrays …but

• They use curly brackets { }• They store elements of different types

x = {s 6}

x = @sphere [6]

x{1}ans = @sphere

x{2}ans = 6

Continuing with GUI

Graphic Objects

• figure• axes• 2D-plot• 3D-plot• axis labels• title

GUI objects• pushbutton• toggle• edit• text• menu

The UIcontrols are common interface controlers

Help us perform specific actions or set the variables for future actions

Actions and options are selected by the mouse, some UIcontrols are also editable so we can use the keyboard as well

Interface controllers

Interface controllers

We can create UIcontrols simply by implementing the following syntax

handle_to_UI=uicontrol(‘Property Name’,’Property Value’);

Interface controllers

UIcontrol types are defined by their ‘style’ property:

Check box 'checkbox'Editable text field 'edit'

Toggle button 'toggle' 'Pop-up menus 'popupmenu'

Push button 'pushbuttonList box 'listbox'

Radio button 'radiobutton'

Static text 'text'

Slider 'slider'Frame 'frame'

Essential properties:

Callback – A string with one or more commands that is executed when the controller is activated.

May be empty – ''

Example uicontrol('style','pushbutton','callback','close(gcf)');

Interface controllersare graphic objects

Essential properties:

Callback – A string with one or more commands that is executed when the controller is activated.

May be empty - ''

Recommendation – always call a function that does what you want.

function closeCurrentFigure(hCallingButton,... eventData) close(gcf)End

uicontrol('style','pushbutton',... 'callback',{@closeCurrentFigure});

Interface controllersare graphic objects

Essential properties:

Callback – A string with one or more commands that is executed when the controller is activated.

May be empty - ''

Recommendation – always call a function that does what you want.

Tag – a string that may be used as a unique identifier of the controller.

h = findobj('Tag','1');

Essential properties :

• Units – 'pixels' (default) or 'norm' (recommended) or

• Position – The vector [Left-lower-corner-X

Left-lower-corner-Y

width height]

If you want to use the 'norm' units you should declare it before the position is set.

Essential properties :

• Value – a scalar

• String

• UserData – a matrix

hToCheckBox =

uicontrol('Style', 'checkbox',...

'Position',[20 450 120 20],...

'String','Check Box example‘, ...

‘Callback’,’’)

Checkboxes allow the user to turn on/off a number of independent options

Note: the position is measured in pixels from the left-bottom corner of the figure

Checkboxes

Represented by the Value property :

1 for checked

0 for unchecked

>>state=get(hToCheckBox,’Value’)

These values correspond to the Max and Min properties of the uicontrol which by default are 1 and 0 respectively

Checkbox state

Examplefunction OnOffFrameuicontrol('style', 'toggle',... 'position', [50 100 150 200],... 'backgroundColor‘, 'b',... 'foregroundColor', 'r',... 'tag', 'onOff',... 'string', 'on',... 'FontSize', 40,... 'callBack', {@onOff},... 'userData', 1);

function OnOffFrameuicontrol('style', 'toggle',... 'position', [50 100 150 200],... 'backgroundColor‘, 'b',... 'foregroundColor', 'r',... 'tag', 'onOff',... 'string', 'on',... 'FontSize', 40,...

'callBack', {@onOff},... 'userData', 1);

Cell arrayA handle to the function onOff

function OnOffFrame uicontrol(: :

:); function onOff(hCallingButton, eventData) state = get(hCallingButton,'userData'); if (state) %on set(hCallingButton,... 'string', 'off',... 'backgroundColor', 'r',... 'foregroundColor', 'b',... 'userData', 0); else set(hCallingButton,'string', 'on',... 'backgroundColor', 'b',... 'foregroundColor', 'r',... 'userData', 1); end end end

function OnOffFrame uicontrol(: :

:); function onOff(hCallingButton, eventData) state = get(hCallingButton,'userData'); if (state) %on set(hCallingButton,... 'string', 'off',... 'backgroundColor', 'r',... 'foregroundColor', 'b',... 'userData', 0); else set(hCallingButton,'string', 'on',... 'backgroundColor', 'b',... 'foregroundColor', 'r',... 'userData', 1); end end end

A handle to the calling controller

A matrix (in this case empty)

Graphic objects

Figure Axes

UI controllers

pushdown button toggle button radio buttons text editor text slider

UI menu

Initialize figure,UI controllers and menu

my_first_GUI – flow chart

Initialize figure,UI controllers and menu

my_first_GUI – flow chart

Activated?

Perform callback

yes

no

UI 1

wait

Initialize figure,UI controllers and menu

my_first_GUI – flow chart

Activated?

Perform callback

yes

no

UI 1

wait

Activated?

Perform callback

yes

no

UI 2

wait

Initialize figure,UI controllers and menu

my_first_GUI – flow chart

Activated?

Perform callback

yes

no

UI 1

wait

Activated?

Perform callback

yes

no

UI 2

wait

Kill?

display?

Calculate and update figure

yes

no

yes

no

Get parameters from UI

Close figure

Main program

function run)the drawing engine(

function draw)actually draws(

my_first_GUI – flow of information

t Caxes handles

edituicontrol

C

slideruicontrol

speed

toggleuicontrol

On/off

pushButtonuicontrol

kill

uimenu

figure

colormap

radioButtonuicontrol

type

Step I – setting the scenefunction my_first_gui draw_figure(600,600)end

Step I – setting the scenefunction my_first_gui draw_figure(600,600)end function draw_figure(width, height) screen_size = get(0,'screenSize'); left = screen_size(1)+5; bottom = screen_size(4)-height-40;

Step I – setting the scenefunction my_first_gui draw_figure(600,600)end function draw_figure(width, height) screen_size = get(0,'screenSize'); left = screen_size(1)+5; bottom = screen_size(4)-height-40;

figure('position',[left bottom width height],... 'menuBar','none'); end

Step II – subplotsfunction my_first_gui draw_figure('the_figure',600,600) main_axes = subplot(7,7,[1 2 3 4 5 6 ... 8 9 10 11 12 13 ... 15 16 17 18 19 20 ... 22 23 24 25 26 27 ... 29 30 31 32 33 34 ... 36 37 38 39 40 41]); small_axes = subplot(7,7,[7 14]);end function draw_figure(tag, width, height) screen_size = get(0,'screenSize'); left = screen_size(1)+5; bottom = screen_size(4)-height-40;

figure('position',[left bottom width height],... 'tag', tag,... 'menuBar','none'); end

Toggle buttons (or switches) are best suited for choosing between options like true/false, on/off and so on

Buttons

Step III – the on/off button

uicontrol('style' ,'toggle',... 'position' ,[0 10 60 30],... 'backgroundColor','b',... 'foregroundColor','r',... 'tag' ,'onOff',... 'string' ,'on',... 'callBack' ,{@onOff},... 'userData' ,1);

on

Step III – the on/off button

function onOff(calling_button, eventData) state = get(calling_button,'userData'); if (state) %on set(calling_button,'string' ,'off',... 'backgroundColor','r',... 'foregroundColor','b',... 'userData' ,0); else set(calling_button,'string' ,'on',... 'backgroundColor','b',... 'foregroundColor','r',... 'userData' ,1); end end

on

function onOff(calling_button, eventData) state = get(calling_button,'userData'); if (state) %on set(calling_button,'string' ,'off',... 'backgroundColor','r',... 'foregroundColor','b',... 'userData' ,0); else set(calling_button,'string' ,'on',... 'backgroundColor','b',... 'foregroundColor','r',... 'userData' ,1); end end

on

Push buttons are designed to launch a specific action like starting or stopping an execution, resetting the content of a form etc.

Buttons

uicontrol('style' , 'pushbutton',... 'position' ,[65 10 60 30],... 'backgroundColor','b',... 'foregroundColor','r',... 'tag' ,'close',... 'string' ,'close',... 'callBack' , {@close_all},... 'userData' ,0);

Step IV– the close button

on close

function close_all(calling_button, eventData) set(calling_button,'userData',1);end

on close

function close_all(calling_button, eventData) set(calling_button,'userData',1);end

on close

Why don’t we close the figure?

Sliders

Sliders provide an easy way to gradually change values between a given range.

Three ways to move the slider

Sliders

The user has three possible way to change the position of the slider

1.Click the arrow buttons => small value changes

2.Click the trough => large value changes

3.Click and drag the slider => depends on user

The default changes are 1% and 10%

SlidersThe range of the slider is defined with the Min and

Max uicontrol properties.

The amount of change related to an user click is controlled with the SliderStep property which is a two element vector ([0.01 0.1] default)

hToVertSlider= uicontrol('Style','slider',...

'Position',[160 10 20 120],...

'Min',10,...

'Max',20,...

'Value',15,... 'SliderStep',[0.1 0.25],...

'Callback','')

We must set a value between Min and Max

Sliders

Given the setting from Min, Max and SliderStep the amount of change to the current Value are as follow:

For an arrow click:

Value = Value + SliderStep(1) * (Max – Min)

16 = 15 + 0.1 * (20 - 10)

For a trough click:

Value = Value + SliderStep(2) * (Max – Min)

17.5 = 15 + 0.25 * (20 - 10)

Step V– the speed slider

uicontrol('style' ,'slider',.... 'position',[130 10 450 30],... 'tag' ,'speedSlider',... 'max' ,pi/2,... 'min' ,0.01,... 'value' ,pi/4);

Step V– the speed slider

uicontrol('style' ,'slider',.... 'position',[130 10 450 30],... 'tag' ,'speedSlider',... 'max' ,pi/2,... 'min' ,0.01,... 'value' ,pi/4);

What about the callback?

Text and editable text Static texts are commonly used to give

instructions or to display other controllers values (such as sliders)

…’Style’,’text’,…

Static text can not execute callbacks.

Editable texts gets string input from the GUI user.

When the user enters the edit field and change its content, only the String property is affected.

Editable text can execute callbacks

Step VI – the text frame

uicontrol('style' ,'text',... 'string' ,'C',... 'tag' ,'C_title',... 'position' ,[490 290 60 70],... 'backgroundColor','y');

What about the callback?

Step VII – the edit window

uicontrol('style' ,'edit',... 'string' ,'1',... 'value' ,1,... 'tag' ,'C',... 'position',[500 300 40 40],... 'callback', {@getC});

function getC(calling_button, eventData) s = get(calling_button,'string'); set(calling_button,'value',str2double(s));end

Radio Buttons

Radio buttons are similar to checkboxes but designed to specify options that are mutually exclusive like in multiple-choice questions

hToRadio1 = uicontrol('Style', 'radio',...

'Position',[20 300 120 20],...

'String','Option1',...

'Callback', {@turnOffTheOtherButtons},...

'Value',1)

Selected

Function turnOffTheOtherButtons

h = findobj('Tag','option1');

set(h,'Value',0);

:

:

Do we need a different function for each button?

Step VIII – the radio buttons

uicontrol('style' ,'radio',... 'string' ,'surf',... 'callback', {@plotTypeButtons},... 'tag' ,'plot_type',... 'position',[490 250 80 30],... 'value' ,1,... 'userdata',1);

uicontrol('style' ,'radio',... 'string' ,'contour3',... 'callback', {@plotTypeButtons},... 'tag' ,'plot_type',... 'position',[490 220 80 30],... 'value' ,0,... 'userdata',0);

Step VIII – the radio buttons

function plotTypeButtons(calling_button, eventData) handles = findobj('tag','plot_type'); set(handles,'value',0); set(calling_button,'value',1);end

Step IX - Now lets use itfunction run(main_axes, small_axes) onOff = findobj('tag','onOff'); speedSlider = findobj('tag','speedSlider'); C_window = findobj('tag','C'); close_button = findobj('tag','close'); type_handels = findobj('tag','plot_type');

Step IX - Now lets use itfunction run(main_axes, small_axes) onOff = findobj('tag','onOff'); speedSlider = findobj('tag','speedSlider'); C_window = findobj('tag','C'); close_button = findobj('tag','close'); type_handles = findobj('tag','plot_type');

How does type_handles differ from the other handles?

kill = get(close_button,'userData'); [x y] = meshgrid(-2:0.2:2); t = 0.001; while (~kill) on = get(onOff,'userData'); C = get(C_window,'value'); speed = get(speedSlider,'value'); kill = get(close_button,'userData');

activeB = findobj(type_handels,'value',1); plotType = get(activeB,'userdata');

if (on) draw(x,y,main_axes,small_axes,t,C,plot_type); t = t + speed; if (t >= 2*pi) t = 0.0001; end end pause(0.1); end

kill = get(close_button,'userData'); [x y] = meshgrid(-2:0.2:2); t = 0.001; while (~kill) on = get(onOff,'userData'); C = get(C_window,'value'); speed = get(speedSlider,'value'); kill = get(close_button,'userData');

activeB = findobj(type_handels,'value',1); plotType = get(activeB,'userdata');

if (on) draw(x,y,main_axes,small_axes,t,C,plot_type); t = t + speed; if (t >= 2*pi) t = 0.0001; end end pause(0.1); end

kill = get(close_button,'userData'); [x y] = meshgrid(-2:0.2:2); t = 0.001; while (~kill) on = get(onOff,'userData'); C = get(C_window,'value'); speed = get(speedSlider,'value'); kill = get(close_button,'userData');

activeB = findobj(type_handels,'value',1); plotType = get(activeB,'userdata');

if (on) draw(x,y,main_axes,small_axes,t,C,plot_type); t = t + speed; if (t >= 2*pi) t = 0.0001; end end pause(0.1); end

kill = get(close_button,'userData'); [x y] = meshgrid(-2:0.2:2); t = 0.001; while (~kill) on = get(onOff,'userData'); C = get(C_window,'value'); speed = get(speedSlider,'value'); kill = get(close_button,'userData');

activeB = findobj(type_handels,'value',1); plotType = get(activeB,'userdata');

if (on) draw(x,y,main_axes,small_axes,t,C,plot_type); t = t + speed; if (t >= 2*pi) t = 0.0001; end end pause(0.1); end

kill = get(close_button,'userData'); [x y] = meshgrid(-2:0.2:2); t = 0.001; while (~kill) on = get(onOff,'userData'); C = get(C_window,'value'); speed = get(speedSlider,'value'); kill = get(close_button,'userData');

activeB = findobj(type_handels,'value',1); plotType = get(activeB,'userdata');

if (on) draw(x,y,main_axes,small_axes,t,C,plot_type); t = t + speed; if (t >= 2*pi) t = 0.0001; end end pause(0.1); end fig = findobj('tag','the_figure'); close(fig);end

cm = uimenu('tag','colorMap','label','Color Map');

Step XI – Adding color map menu

cm = uimenu('tag','colorMap','label','Color Map'); uimenu(cm, 'label','jet', ‘callback',{@set_colorMap,jet});uimenu(cm, 'label','hot', 'callback',{@set_colorMap,hot});uimenu(cm, 'label','cool', 'callback',{@set_colorMap,cool});

Step XI – Adding color map menu

function set_colorMap(calling_manu, eventData,colorMap) set(gcf,'colorMap',colorMap); parent = get(calling_manu,'parent'); all = get(parent,'children'); set(all,'checked','off'); set(calling_manu,'checked','on'); end

hToCheckBox =

uicontrol('Style', 'checkbox',...

'Position',[20 450 120 20],...

'String','Check Box example‘, ...

‘Callback’,’’)

Checkboxes allow the user to turn on/off a number of independent options

Note: the position is measured in pixels from the left-bottom corner of the figure

Checkboxes