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ans =
12
% commenting operator in matlab
%12
a=23
a =
23
a=23; %; is a output suppressor operator
who
Your variables are:
a ans
whos
Name Size Bytes Class Attributes
a 1x1 8 double
ans 1x1 8 double
who---- This command lists the variables in workspace.
whos----This command details the variables in workspace.
12+23
ans =
35
12-23
ans =
-11
mul=12*23
mul =
276
div=12/23;
% ; is the output suppressing operator
who
Your variables are:
a ans div mul
div
div =
0.5217
1/2
ans =
0.5000
2/1
ans =
2
1/2
ans =
0.5000
1\2
ans =
2
% \ is the inverted division operator a\b=b/a
2/3
ans =
0.6667
2\3
ans =
1.5000
3/2
ans =
1.5000
% exponential representation
1e3
ans =
1000
% e and E holds fine
1E3
ans =
1000
% But, matlab is case-sensitive
a=exp(2)
a =
7.3891
A=exp(1)
A =
2.7183
who
a A
% lookfor ----This command is used for command search
% Syntax: lookfor keywork_to_search
% we know the relation between exponential and logarithm
q=exp(12)
q =
1.6275e+05
log(q)
ans =
12
% = assignment operator
% == equivalence operator, tests equality between variables on both sides
% == results 1, if both are equal; 0, if they are not equal
1==2
ans =
0
1==1
ans =
1
a=exp(12),b=log(a)
a =
1.6275e+05
b =
12
log(exp(12))
ans =
12
exp(log(12))
ans =
12
% log ---command to compute natural logarithm
% log10---command to compute base 10 logarithm
exp(log10(12))
ans =
2.9423
log10(exp(12))==log(exp(12))
ans =
0
% both are not equal
log10(10^12)==10^(log10(12))
ans=
1
%both are equal
%trigonometric computations
sin(90)
ans =
0.8940
pi
ans =
3.1416
22/7
ans =
3.1429
sin(pi/2)
ans =
1
sin(pi/2)==sin(90)
ans =
0
sin(0)
ans =
0
asin(sin(pi/2))
ans =
1.5708
asin(sin(90))
ans =
1.1062
sin(5)
ans =
-0.9589
% Matlab’s trig functions are permanently set to radians mode
% The up-arrow key will display previous commands.
% And when you back up to a previous command that you like, hit Enter and it will execute.
% Or you can edit it when you get to it (use , , and Del), then execute it. Try doing this
% Now to re-execute the commands you have already typed.
diary off
clear all %to clear the workspace. Execute and observe the workspace window
close all % closes safely all the windows opened, except main window and the editor window
clc%clears the command window. Execute it and observe the command window
who
% As "clear all" command clears all the variables; so "who" can't display any variable.
% who lists active variables
% whos----lists active variables and their sizes
% what-------lists .m files available in the current directory
% Numerical Accuracy in MATLAB
225/331
ans =
0.6798
format long e
225/331
ans =
6.797583081570997e-01
format short% (the default format)
225/331
ans =
0.6798
format long
225/331
ans =
0.679758308157100
format short e
%e stands for exponential notation
225/331
ans =
6.7976e-01
format bank
225/331
ans =
0.67
format short% (the default format)
225/331
ans =
0.6798
pi
ans =
3.1416
who
Your variables are:
ans
pi=2%can be done
pi =
2
who
Your variables are:
ans pi
pi
pi =
2
% please don't do so. "pi" was assigned to 3.1416, by default
pi=3.1416
pi =
3.1416
clear all
pi
ans =
3.1416
power(2,5)
ans =
32
power(10,2)
ans =
100
pow2(2)
ans =
4
%pow2(2) means 2^2
%X = pow2(Y) for each element of Y is 2 raised to the power Y
% X = pow2(F,E) for each element of the real array F and a integer
% array E computes X = F .* (2 .^ E).
X = pow2(Y) for each element of Y is 2 raised to the power Y
sqrt(25)
ans =
5
% sqrt---to calculate the squarate
% working with complex numbers
a=2+2j
a =
2.0000 + 2.0000i
b=3+5i
b =
3.0000 + 5.0000i
% either "i" or "j" can be used to represent the imaginary number
diary off
2j
ans =
0 + 2.0000i
2i
ans =
0 + 2.0000i
%but, the notation "i2" or "j2" is forbidden
i2
{ Undefined function or variable 'i2'.
}
j2
{ Undefined function or variable 'j2'.
}
% abs----to calculate the absolute value of a complex number
who
Your variables are:
a ans b
w=3;
abs(w)
ans =
3
% abs(real_number)=real_number
% abs(imaginary_number)=real_number
abs(3j)
ans =
3
abs(3.33j)
ans =
3.3300
a
a =
2.0000 + 2.0000i
abs(a)
ans =
2.8284
%abs(m+nj)=sqrt(power(m,2)+power(n,2))
sqrt(power(2,2)+power(2,2))
ans =
2.8284
z1=1+2i
z1 =
1.0000 + 2.0000i
%% or you can multiply by i, like this
z1=1+2*i
z1 =
1.0000 + 2.0000i
z2=2-3i
z2 =
2.0000 - 3.0000i
% add and subtract
addition=z1+z2
addition =
3.0000 - 1.0000i
subtraction=z1-z2
subtraction =
-1.0000 + 5.0000i
% multiply and divide
multiply=z1*z2
multiply =
8.0000 + 1.0000i
division=z1/z2
division =
-0.3077 + 0.5385i
d1=z1\z2
d1 =
-0.8000 - 1.4000i
z=3+4i
z =
3.0000 + 4.0000i
real(z)
ans =
3
imag(z)
ans =
4
conj(z)
ans =
3.0000 - 4.0000i
abs(z)
ans =
5
angle(z)
ans =
0.9273
diary off
%angle(m+nj)=atan(b/a)
z
z =
3.0000 + 4.0000i
atan(4/3)==angle(3+4j)
ans =
1
%Here, 1 means both are equal
%Euler’s famous formula e
%exp(xi)= cos x + i sin x
exp(i*pi/4)
ans =
0.7071 + 0.7071i
%% Housekeeping Functions
% ceil(x)---the nearest integer to x looking toward +
% close 3--- closes figure window 3
% fix(x)---- the nearest integer to x looking toward zero
% fliplr(A)------ flip a matrix A, left for right
% flipud(A)-----flip a matrix A, up for down
% floor(x)------- the nearest integer to x looking toward -
% length(a)------the number of elements in a vector
% mod(x,y)-----the integer remainder of x/y; see online help if x or y are negative
% rem(x,y)------the integer remainder of x/y; see online help if x or y are negative
% rot90(A)------rotate a matrix A by 90
% round(x)------the nearest integer to x
% sign(x)--------the sign of x and returns 0 if x=0
% size(c)---------the dimensions of a matrix
Working With MATLAB
Type the following following commands in the Command Window, and observe(verify) their corresponding results
12ans =
12
% commenting operator in matlab
%12
a=23
a =
23
a=23; %; is a output suppressor operator
who
Your variables are:
a ans
whos
Name Size Bytes Class Attributes
a 1x1 8 double
ans 1x1 8 double
who---- This command lists the variables in workspace.
whos----This command details the variables in workspace.
12+23
ans =
35
12-23
ans =
-11
mul=12*23
mul =
276
div=12/23;
% ; is the output suppressing operator
who
Your variables are:
a ans div mul
div
div =
0.5217
1/2
ans =
0.5000
2/1
ans =
2
1/2
ans =
0.5000
1\2
ans =
2
% \ is the inverted division operator a\b=b/a
2/3
ans =
0.6667
2\3
ans =
1.5000
3/2
ans =
1.5000
% exponential representation
1e3
ans =
1000
% e and E holds fine
1E3
ans =
1000
% But, matlab is case-sensitive
a=exp(2)
a =
7.3891
A=exp(1)
A =
2.7183
who
a A
% lookfor ----This command is used for command search
% Syntax: lookfor keywork_to_search
% we know the relation between exponential and logarithm
q=exp(12)
q =
1.6275e+05
log(q)
ans =
12
% = assignment operator
% == equivalence operator, tests equality between variables on both sides
% == results 1, if both are equal; 0, if they are not equal
1==2
ans =
0
1==1
ans =
1
a=exp(12),b=log(a)
a =
1.6275e+05
b =
12
log(exp(12))
ans =
12
exp(log(12))
ans =
12
% log ---command to compute natural logarithm
% log10---command to compute base 10 logarithm
exp(log10(12))
ans =
2.9423
log10(exp(12))==log(exp(12))
ans =
0
% both are not equal
log10(10^12)==10^(log10(12))
ans=
1
%both are equal
%trigonometric computations
sin(90)
ans =
0.8940
pi
ans =
3.1416
22/7
ans =
3.1429
sin(pi/2)
ans =
1
sin(pi/2)==sin(90)
ans =
0
sin(0)
ans =
0
asin(sin(pi/2))
ans =
1.5708
asin(sin(90))
ans =
1.1062
sin(5)
ans =
-0.9589
% Matlab’s trig functions are permanently set to radians mode
% The up-arrow key will display previous commands.
% And when you back up to a previous command that you like, hit Enter and it will execute.
% Or you can edit it when you get to it (use , , and Del), then execute it. Try doing this
% Now to re-execute the commands you have already typed.
diary off
clear all %to clear the workspace. Execute and observe the workspace window
close all % closes safely all the windows opened, except main window and the editor window
clc%clears the command window. Execute it and observe the command window
who
% As "clear all" command clears all the variables; so "who" can't display any variable.
% who lists active variables
% whos----lists active variables and their sizes
% what-------lists .m files available in the current directory
% Numerical Accuracy in MATLAB
225/331
ans =
0.6798
format long e
225/331
ans =
6.797583081570997e-01
format short% (the default format)
225/331
ans =
0.6798
format long
225/331
ans =
0.679758308157100
format short e
%e stands for exponential notation
225/331
ans =
6.7976e-01
format bank
225/331
ans =
0.67
format short% (the default format)
225/331
ans =
0.6798
pi
ans =
3.1416
who
Your variables are:
ans
pi=2%can be done
pi =
2
who
Your variables are:
ans pi
pi
pi =
2
% please don't do so. "pi" was assigned to 3.1416, by default
pi=3.1416
pi =
3.1416
clear all
pi
ans =
3.1416
power(2,5)
ans =
32
power(10,2)
ans =
100
pow2(2)
ans =
4
%pow2(2) means 2^2
%X = pow2(Y) for each element of Y is 2 raised to the power Y
% X = pow2(F,E) for each element of the real array F and a integer
% array E computes X = F .* (2 .^ E).
X = pow2(Y) for each element of Y is 2 raised to the power Y
sqrt(25)
ans =
5
% sqrt---to calculate the squarate
% working with complex numbers
a=2+2j
a =
2.0000 + 2.0000i
b=3+5i
b =
3.0000 + 5.0000i
% either "i" or "j" can be used to represent the imaginary number
diary off
2j
ans =
0 + 2.0000i
2i
ans =
0 + 2.0000i
%but, the notation "i2" or "j2" is forbidden
i2
{ Undefined function or variable 'i2'.
}
j2
{ Undefined function or variable 'j2'.
}
% abs----to calculate the absolute value of a complex number
who
Your variables are:
a ans b
w=3;
abs(w)
ans =
3
% abs(real_number)=real_number
% abs(imaginary_number)=real_number
abs(3j)
ans =
3
abs(3.33j)
ans =
3.3300
a
a =
2.0000 + 2.0000i
abs(a)
ans =
2.8284
%abs(m+nj)=sqrt(power(m,2)+power(n,2))
sqrt(power(2,2)+power(2,2))
ans =
2.8284
z1=1+2i
z1 =
1.0000 + 2.0000i
%% or you can multiply by i, like this
z1=1+2*i
z1 =
1.0000 + 2.0000i
z2=2-3i
z2 =
2.0000 - 3.0000i
% add and subtract
addition=z1+z2
addition =
3.0000 - 1.0000i
subtraction=z1-z2
subtraction =
-1.0000 + 5.0000i
% multiply and divide
multiply=z1*z2
multiply =
8.0000 + 1.0000i
division=z1/z2
division =
-0.3077 + 0.5385i
d1=z1\z2
d1 =
-0.8000 - 1.4000i
z=3+4i
z =
3.0000 + 4.0000i
real(z)
ans =
3
imag(z)
ans =
4
conj(z)
ans =
3.0000 - 4.0000i
abs(z)
ans =
5
angle(z)
ans =
0.9273
diary off
%angle(m+nj)=atan(b/a)
z
z =
3.0000 + 4.0000i
atan(4/3)==angle(3+4j)
ans =
1
%Here, 1 means both are equal
%Euler’s famous formula e
%exp(xi)= cos x + i sin x
exp(i*pi/4)
ans =
0.7071 + 0.7071i
%% Housekeeping Functions
% ceil(x)---the nearest integer to x looking toward +
% close 3--- closes figure window 3
% fix(x)---- the nearest integer to x looking toward zero
% fliplr(A)------ flip a matrix A, left for right
% flipud(A)-----flip a matrix A, up for down
% floor(x)------- the nearest integer to x looking toward -
% length(a)------the number of elements in a vector
% mod(x,y)-----the integer remainder of x/y; see online help if x or y are negative
% rem(x,y)------the integer remainder of x/y; see online help if x or y are negative
% rot90(A)------rotate a matrix A by 90
% round(x)------the nearest integer to x
% sign(x)--------the sign of x and returns 0 if x=0
% size(c)---------the dimensions of a matrix
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