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Simple GUI Calculator in MATLAB

Simple GUI calculator

I first created a simple GUI for the calculator to perform +-*/.

When the user click the button the function arithmetic is called.

Additional Information: To perform all the complex calculations use Texas Instruments.

function calculator

figure('Position',[200 200 220 200],'Name','Calculator','NumberTitle','off','MenuBar','None','Resize','off');

txt=uicontrol('Style','Text','Position',[10 165 200 30],'String','0');

global stack value top op tops opstack num1 num2 flag;

flag=0;

x=10;

y=130;

top=1;

tops=1;

name=['7','8','9','/','4','5','6','*','1','2','3','-','0','+','C','='];%k

for k=1:size(name,2)

uicontrol('Style','Pushbutton','Position',[x y 50 30],'String' ,name(k),'Callback',@arithmetic) ;

x=x+50;

if(mod(k,4)==0)

x=10;y=y-35;

end

The String value of the pressed button is obtained using the get(object,’String’) function.

If the value is a number then it is placed in a stack.

If the value is a operator then the operator will be placed in the operator stack (opstack).

If the value is ‘C’ then the stacks top is set to 1.

function arithmetic(object,~)

num=str2double(get(object,'String'));

if((num>=0)&&(num<=9))

value=num;

evaluate();

else

op=get(object,'String');

if(op=='C')

top=1;

tops=1;

set(txt,'String','0');

else

operator();

end

The function evaluate is called to add the number to the stack.

If the stack (1) =0 and the stack (2) =9, then the stack (1) =9.

This is because, when the user enters zero and then 1, the stack value will be ‘01’. To obtain the correct value, it is better to remove the zero and display as ‘1’.

If the user enters numbers continuously without entering an operator then the values should be concatenated at each time.

For example, if the user enter 2, 4, 5 and then +, the values 245 should be displayed as a single number.

function evaluate()

stack(top)=value;

if((stack(1)==0)&&(top==2))

stack(1)=stack(top);

top=top-1;

end

str=num2str(stack(1));

for i=2:top

str=strcat(str,num2str(stack(i)));

end

top=top+1;

set(txt,'String',' ');

set(txt,'String',str);

flag=0;

end

If the user enter an operator then the operator will be added to the operator stack and the first number to perform the arithmetic operation is stored in the variable ‘num1’.

If the user enters an operator again then the operator will be added to the stack and the second number will be stored in the variable ‘num2’.

After getting the two numbers, the corresponding arithmetic operation is done based on the operator in the opstack(1).

The result will be stored in the variable ‘num1’.

function operator()

if((top~=1)||(flag==1))

opstack(tops)=op;

tops=tops+1;

if((tops==2)&&(flag~=1))

str=num2str(stack(1));

for i=2:top-1

str=strcat(str,num2str(stack(i)));

end

num1=str2double(str);

flag=1;

top=1;

elseif(tops>=3)

if(flag==0)

str=num2str(stack(1));

for i=2:top-1

str=strcat(str,num2str(stack(i)));

end

num2=str2double(str);

top=1;

if(opstack(tops-1)=='=')

calculate();

set(txt,'String',' ');

set(txt,'String',num2str(num1));

flag=1;

tops=1;

else

calculate();

set(txt,'String',' ');

set(txt,'String',num2str(num1));

flag=1;

tmp=opstack(tops-1);

opstack(1)=tmp;

tops=tops-1;

end

else

tmp=opstack(tops-1);

opstack(1)=tmp;

tops=tops-1;

end

function calculate()

switch (opstack(1))

case '+'

num1=num1+num2;

case '-'

num1=num1-num2;

case '/'

num1=num1/num2;

case '*'

num1=num1*num2;

end

Did u find the material useful?

The Essential Guide to User Interface Design: An Introduction to GUI Design Principles and Techniques (CourseSmart)

User Interface Design for Programmers

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Excel file to matlab

EXCEL2UITABLE:

Steps to import excel file to matlab:

Method: 1

The data from excel file can be imported to matlab using xlsread function.

[numericdata,stringdata]=xlsread(filename, sheet name);

The numeric data in the sheet will be stored in the first variable ‘numericdata’.

The strings or characters in the sheet will be stored in the second variable ‘stringdata’.

Method : 2

Using uiimport , the user can interactively select the rows and data.

Syntax: uiimport('Employee.xls')

Sample program:

Here, a excel file by name ‘Employee.xls’ with sheet name ‘Employee Details’ contains some employee details. The details are imported from excel to matlab.

To obtain the heading of each column:

%[data heading]=xlsread('Employee.xls','Employee Details','A1:B1:C1');

[ID Text]=xlsread('Employee.xls','Employee Details');

The numeric and string data are stored in the ID and Text respectively.

To display the sheet in a table format:

The employee id,employee name and employee date of join is stored.

To calculate the experience of each employee, the date of join obtained is converted to datenum and it is subtracted from the current date.

num=floor(now)-datenum(Text(i,3));

The number of years is obtained by using the function datestr(num,11);

Here the value 11 will return the years in ‘YY’ format.

f = figure('Position',[400 400 400 150],'Name','Employee Details','NumberTitle','off');

dat=cell(size(Text,1),size(Text,2)+1);

for i=2:size(Text,1)

num=floor(now)-datenum(Text(i,3));

exp=datestr(num,11);

dat(i-1,1)={ID(i-1,1)};

dat(i-1,2)=Text(i,2);

dat(i-1,3)=Text(i,3);

dat(i-1,4)={exp};

end

columnname={'Employee ID','Employee Name','Date Of Join','Experience'};

columnformat = {'numeric', 'char', 'char', 'numeric'};

uitable('Units','normalized','Position',...

[0.1,0.1,.9,.9], 'Data', dat,...

'ColumnName', columnname,...

'ColumnFormat', columnformat,'RowName',[]);

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Simple Image Thresholding using GUI component Slider

Thresholding is one of the steps performed on the image during image conversion.
Also Learn: Otsu's thresholding method

It is used for separating the background from the foreground.

The user can drag the slider to adjust the Thresholding. The slider value ranges between 0 and 255.

MATLAB CODE:

function f=mainthresh()

%The window size of the image is adjusted based on the screen size.

global T1;

ssz = get(0,'ScreenSize');

figure('Visible','on','Name','IMAGE THRESHOLDING','NumberTitle','off','Position',ssz);

axes('units','pixels','Position',[ssz(3)/45 ssz(4)/4 ssz(3)-(ssz(3)/4) ssz(4)-(ssz(4)/3)]);

in=imread('coins.png');

imshow(in);

set(gca,'xtick',[],'ytick',[])

%The Slider is one of the GUI component in MATLAB. The Value of the slider is between 0 and 255.

%These values can be changed based on the image type.

slid=uicontrol('Style','Slider','Visible','on','Value',1,'Max',255,'Min',0,'Sliderstep',[1 1],'Position',[ssz(3)/35 ssz(4)/5 ssz(3)-(ssz(3)/3) 20],'Callback', @threshing_image);

ent=uicontrol('Style','pushbutton','Visible','on','String','THRESHOLD VALUE','Position',[ssz(3)-(ssz(3)/4) ssz(4)-(ssz(4)/8) 105 30]);

ed=uicontrol('Style','edit','Visible','on','String','0','Value',1,'Position',[ssz(3)-(ssz(3)/4) ssz(4)-(ssz(4)/6) 90 20]);

%When the slider is moved the corresponding position value is passed to the function 'threshing_image' .

%The original image is passed to another function 'Imthreshold'.

function threshing_image(object,~)

val=get(object,'value');

in=imread('coins.png');

T1=Imthreshold(in,val);

imshow(T1);

set(gca,'xtick',[],'ytick',[])

set(ed,'String',val);

end

%Based on the value passed, the image background is separated from the foreground.

%In this example, the background of the coins image contains pixel values less than 80.

%By adjusting the slider to value 80 the background area gets value zero and the coins appear as it is.

function Im=Imthreshold(Image,Tvalue)

%Replace the pixel value either with 0 or 255.

Image( find ( Image(:,:,1) < Tvalue ) )=255;

Im=Image;

end

f=T1;

end

Thresholded Image

Here is another example , This Image is RGB. So we have to consider the RED, GREEN and BLUE pixel values.

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