(New page: The bug in the matlab code was the value of Ts set equal to 0.07. By dividing the value by 10000, the full function from t values 0 to 1 are displayed in the graph output that were otherwi...)
 
 
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The bug in the matlab code was the value of Ts set equal to 0.07. By dividing the value by 10000, the full function from t values 0 to 1 are displayed in the graph output that were otherwise overlooked.
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Linearity! A concept that is easy to understand with the right definition!
  
F0 =13;
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A system may be defined as linear if for every independent variable value 'x' put into the system, representing by equation y = f(x), there is a unique dependent variable value 'y.'
T0 =1/F0;
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Ts = 0.07/10000;
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t  = 0:Ts:13*T0;
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x = real(exp(j*(2*pi*F0*t-pi/2)));
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plot(t,x);
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The results of running the code above yields
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An example of a linear system is a straight line with slope m = 1 represented by the equation y = x. An example of a non-linear system would be a system represented by the equation y = x^2.
  
[[Image:HW2_Image_ECE301Fall2008mboutin.jpg]]
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An easy way to prove if a system is linear is to plot the equation representing the system and then draw a horizontal line, i.e. y = 1, and observe at how many points the line crosses through the equation. If the two lines intersect only once for all values of x then the system is linear. Otherwise, if the two equations intersect at more than one location then the system is non-linear. Indeed, the equations y = x and y = 1 will intersect only once at (x,y) = (1,1), while the equations y = x^2 and y = 1 will intersect at the locations (-1,1) and (1,1). These results prove that y = x represents a linear system and y = x^2 represents a non-linear system!

Latest revision as of 13:16, 12 September 2008

Linearity! A concept that is easy to understand with the right definition!

A system may be defined as linear if for every independent variable value 'x' put into the system, representing by equation y = f(x), there is a unique dependent variable value 'y.'

An example of a linear system is a straight line with slope m = 1 represented by the equation y = x. An example of a non-linear system would be a system represented by the equation y = x^2.

An easy way to prove if a system is linear is to plot the equation representing the system and then draw a horizontal line, i.e. y = 1, and observe at how many points the line crosses through the equation. If the two lines intersect only once for all values of x then the system is linear. Otherwise, if the two equations intersect at more than one location then the system is non-linear. Indeed, the equations y = x and y = 1 will intersect only once at (x,y) = (1,1), while the equations y = x^2 and y = 1 will intersect at the locations (-1,1) and (1,1). These results prove that y = x represents a linear system and y = x^2 represents a non-linear system!

Alumni Liaison

Basic linear algebra uncovers and clarifies very important geometry and algebra.

Dr. Paul Garrett