MATLAB Basics Part 1

1.What is MATLAB ?

To solve Math & Engineering problems this is been created to using syntax like common science & engineering notation. 

--Cleve Moler [Professor] built this for their students

2.Which fields this is been used ?

• Machine Learning
• Robotics
• Image Process
• Biology
• Engineers & Scientists also uses to develop
• Automation
• Medical Devices
• Solar Systems
• etc..

3.Is MATLAB is case sensitive ?

Yes,Variables & Function names are case sensitive.

Note : If observes,So even though generally quotes MATLAB is case sensitive programming language is not completely ,Like below where allows case insensitive 

• Property Names
• Scripts and Functions stored in a MATLAB file with a .m extension in Windows 

4.strcmp VS strcmpi ?

Both compares the string and "strcmpi" ignores the case while comparing.

5.MATLAB Variables ?

Ex: pi -->Default function

6.Write the expression for below example ?

>> a=3;

>> b=2;

>> c=-6;

>> x1=(-b+sqrt(b^2-4*a*c))/(2*a)

x1 =

    1.1196

>> x2 = (-b-sqrt(b^2-4*a*c))/(2*a)

x2 =

   -1.7863

7.Functions & Vector Array declaration ?

8.plot(x,y) function example?xlim,ylim functions use?How to increase the number of elements of X & Y axis ?

-->xlim,ylim sets the axis limits

-->As you observe the plot is getting more line elements based on available space,So it will auto selects the points linspace based on the available space. linspace also a function can set custom value

9.linspace function ? Uniformly Spaced Vectors example ?
Ex:Find temperature in Centigrade and Fahrenheit

10.How to add the comments ?
%{Comment Text}%

11.What is logical Vector ?How logical Vector access original Vector ?

Logical Vector is used to access only specific data based on certain conditions.
Script :

>> %{Original Vector}% >> data = [0.01;0.02;0.01;0.27;0.39;0.01;0.65;0.50]; >> %{Logical Vector}% >> ind = data > 0.1; >> activity =data(ind); >> %{Get the result from Original Vector with below condition}% >> ind = data <=0.1; >> %{Update the original vector data - values<=0.1 to 0 }% >> data(ind) = 0;

12.Element Wise Vector Operations (*  /  ^) ?
Script :

>>v1 = [1,2,3,4]; >>v2 = [2,4,6,8]; >>M =  v1.*v2; >>D =  v2./v1; >>S =  v1.^v2; >>A =  v1+ v2; >>Sub =  v2- v1;

1.For all the operation Vector Dimensions should be same
2.Should precede by  '.' for these vector operations  like  v1.*v2, v1 ./v2 , v1 .^v2

13.Smooth plotting with more number of elements ?
Script :

>>%{f(x) = 3x^2 + 2x -6}% >>x = -2:0.1:2; >>y = 3*x.^2 + 2*x -6; >>plot(x,y);

13.Vector Transpose ?
Rows to Columns & Columns to Rows
Script :

>>%{Vector Transpose}% >>v = [2 -1 8.5 6 19]; >>c = v';