Everything about Vehicle Simulation

Sunday, July 30, 2017

[Matlab GUI] Build simple Data Processing tool - 2/5

2. Load mat file in structure array, and Display file list loaded on the listbox

We here create the function which loads *.mat file in structure array type. The button 'Load' shown below will call this function.

Before adding the function into the button 'Load', some setting should be done in advance.
1) Right-click on the button 'Load'.
2) Select the menu 'Property Inspector'. Then, the figure below will appear.

3) Change the Tag name on the Property Inspector window above.
As in the same way, change the Tag name of the Listbox.

4) In the pop-up menu appearing by the right-click on the button 'Load',
select the menu 'View Callbacks > Callback'. Then, the corresponding function is added and m-script appears on the screen as below.
Here, the tag name defined at 3) becomes the name of callback function.

* Create a load callback function
1) To open and select *.mat files, the file directory is necessary.
It is easily obtained using the Matlab function 'uigetdir'.

directory = uigetdir(' ','Select a folder');

2) Get file list

result = dir(directory);
allist = struct2cell(result);
s=size(allist); n=s(2)-2; list=cell(1,n);
for N=1:1:n
list{1,N} = allist{1,N+2};
end

3) Filtering the list

matfile = ~cellfun(@isempty,strfind(list,'.mat'));
mf = double(matfile);
total = logical(mf);
list = list(total);

4) Display the filtered list
Supposing that the Tag name of the Listbox is 'FileList', file list can be displayed using the command below.

set(handles.FileList,'String',list);

After all, the code looks as following.
%
directory = uigetdir(' ','Select a folder');
%
result = dir(directory);
allist = struct2cell(result);
s=size(allist); n=s(2)-2; list=cell(1,n);
for N=1:1:n
list{1,N} = allist{1,N+2};
end
%
matfile = ~cellfun(@isempty,strfind(list,'.mat'));
mf = double(matfile);
total = logical(mf);
list = list(total);
%
set(handles.FileList,'String',list);

Related posts
0. Build simple plot tool.
1. Create a tool layout in GUIDE
2. Load mat file in structure array, and Display the file list loaded on the listbox
3. Display variables of mat file, and Plot variables on the axes
4. How to add new plot to the existing plot, and Use dynamic legend
5. Clear the axes, and Move the figure to new figure (Undock)

Monday, July 17, 2017

[Matlab GUI] Build simple Data Processing tool - 1/5

1. Create a tool layout in GUIDE
There are two ways to create UI(User Interface) in Matlab. One is to create UIs programmatically, and the other is to create UIs using Matlab app called GUIDE.
Both can do almost the same thing, but some syntax are different, and developing UIs programmatically takes more time. If you are new to UI development, GUIDE is recommended. Anyway, let's bring it on.

Before getting started, see https://www.mathworks.com/help/matlab/creating_guis/about-the-simple-guide-gui-example.html

# Getting started with GUIDE layout editor
1) Start GUIDE by typing 'guide' on the Matlab command window

2) 'GUIDE Quick Start' window appears, then click 'OK'.

3) Layout editor

# Create an UI

1) Component name.

2) Add the components in the layout edit as below.

3 pushbuttons, 2 static texts, 2 pop-up menus, 1 listbox, and 1 axes

3) After layout, save the figure.

'File > Save' or 'Ctrl+S'

After save, you see m script created automatically. This m script is used to insert functions to implement the UI created by GUIDE above.

0. Build simple plot tool.
1. Create a tool layout in GUIDE
2. Load mat file in structure array, and Display the file list loaded on the listbox
3. Display variables of mat file, and Plot variables on the axes
4. How to add new plot to the existing plot, and Use dynamic legend
5. Clear the axes, and Move the figure to new figure (Undock)

Thursday, July 13, 2017

[Matlab GUI] Build simple Data Processing tool - 0/5

Matlab can easily plot variables with the powerful functions provided as default, but often annoying to define at least x vector and y vector on the command window, especially when plotting variables of structure format of mat file.
In order to draw figures, first of all you should load *.mat file to the workspace, and second, determine variables to plot, and then can draw a figure using the function 'plot'. In addition to this, you can also use the function, 'legend', 'xlabel', 'ylabel', etc.
If you want to add line plot to the existing figure, you can use 'hold on' or 'hold all'.

It is not that difficut to do what has been explained so far, but would be more happy if you have some convenient tool. This kind of simple tool can be developed by Matlab GUIDE.
Let me post how to create it with GUIDE. Let's make it together.

Related posts
1. Create a tool layout in GUIDE
2. Load mat file in structure array, and Display the file list loaded on the listbox
3. Display variables of mat file, and Plot variables on the axes
4. How to add new plot to the existing plot, and Use dynamic legend
5. Clear the axes, and Move the figure to new figure (Undock)

Wednesday, July 12, 2017

[Matlab] Create a log file using 'fopen', 'fprintf', and 'fclose'

A log file is often required to write warnings, errors, and etc while running a simulation, so we can know what has happened during the simulation.
Let's see how to create a log file with Matlab.

----------------------------------------------
% Variables and data
variable = {'engine','tm','driver'};
data = [1, 2, 3;4, 5, 6;7, 8, 9];

% Path
path =[pwd,'\Configuration'];
name = 'log.txt';
file = fullfile(path,name);
[fid,msg] = fopen(file,'w+'); % 'w+' open a file for adding to end line
if fid == -1
error(msg);
else
% Start date and time
sStart = clock;
sStart = sprintf('%d%s%d%s%d%s%d%s%d%s',sStart(1),'-',sStart(2),'-',...
sStart(3),', ',sStart(4),'h',sStart(5),'m');
fprintf(fid,'%s%s\n','Start : ',sStart);

% Write variables
for N=1:1:length(variable)
if N < length(variable)
fprintf(fid,'%s\t\t',variable{N});
elseif N == length(variable)
fprintf(fid,'%s\n',variable{N});
end

end

fprintf(fid,'%d\t\t%d\t\t%d\n',data);

% End date and time
sEnd = clock;
sEnd = sprintf('%d%s%d%s%d%s%d%s%d%s',sEnd(1),'-',sEnd(2),'-',sEnd(3),...
', ',sEnd(4),'h',sEnd(5),'m');
fprintf(fid,'%s%s\n','End : ',sEnd);
end
fclose(fid);
--------------------------------------------------

As a result of the code above, the following log is created.
------------------------------------
Start : 2017-7-13, 10h33m
engine tm driver
1 4 7
2 5 8
3 6 9
End : 2017-7-13, 10h33m
---------------------------------------

% fopen option
FID = fopen(FILENAME,PERMISSION) opens the file FILENAME in the
mode specified by PERMISSION:

'r' open file for reading
'w' open file for writing; discard existing contents
'a' open or create file for writing; append data to end of file
'r+' open (do not create) file for reading and writing
'w+' open or create file for reading and writing; discard
existing contents
'a+' open or create file for reading and writing; append data
to end of file
'W' open file for writing without automatic flushing
'A' open file for appending without automatic flushing

Monday, July 10, 2017

[Matlab GUI] Uitab and ButtonDownFcn

Using 'ButtonDownFcn', advanced functions can be implemented in MATLAB GUIDE.

For example, depending on the tab selected by clicking, strings displayed on the buttons can be changed. See the example below.

1. Place the code below into the XXX_OpeningFcn
--------------------------------
% Suppress an annoying warning message
warning off MATLAB:uitabgroup:OldVersion

%---- Create a tab group
handles.tgroup = uitabgroup('Parent',handles.mainGui,'TabLocation','top');
% Set position [left, bottom, width, height], normalized unit
set(handles.tgroup,'Units','Normalized','Position',[0 0 1 0.945]);
% Create each tab
handles.maintab = uitab('Parent',handles.tgroup,'Title',' Main ',...
'ButtonDownFcn',@tabmain);
handles.doetab = uitab('Parent',handles.tgroup,'Title',' DoE ',...
'ButtonDownFcn',@tabdoe);
handles.simulinktab = uitab('Parent',handles.tgroup,'Title','Simulink',...
'ButtonDownFcn',@tabsimulink);
% Place panels into each tab
set(handles.Tab1,'Parent',handles.maintab);
set(handles.Tab2,'Parent',handles.doetab);
set(handles.Tab3,'Parent',handles.simulinktab);

% Reposition each panel to the same location as Tab1
set(handles.Tab2,'Position',get(handles.Tab1,'Position'));
set(handles.Tab3,'Position',get(handles.Tab1,'Position'));
--------------------------------------------------------------------------------

2. Create functions tabmain, tabdoe, and tabsimulink
One of three functions could be created as below.

-----------------------------------
% When clicking the tab 'DoE '
function tabdoe(hObject,~,~)

handles = guidata(hObject);
% Enable buttons
set(handles.Run,'Enable','on');
set(handles.ImportAll,'Enable','on');
set(handles.ExportAll,'Enable','on');
% Set button string
set(handles.Run,'String','Run(D)');
set(handles.ImportAll,'String','Load');
set(handles.ExportAll,'String','Save');

guidata(hObject,handles);
-----------------------------------------

Related Post
1. Create tabs using uitab and uitabgroup