What are Complex Signals and How Do They Differ from Sine and Cosine Functions?

[premagg]

Hi all,
I want to know about the complex signals.They say that it is a complex signal and cannot be plotted but at the same time give analogy with cosine or sine functions.Please clear me about this.

 

[wildman]

Who told you that complex signals can't be plotted? Of course they can be plotted, but in the complex plane of course. There is also a direct relation between complex exponentials and cosines and sines. It is called euler's equation. It is too complicated to explain it all here, but if you want to learn more I highly recommend a very simple (but very correct) book on the subject titled "Who is Fourier? A Mathematical Adventure" by the Transnational College of Lex. It explains it all in great detail.

 

[premagg]

kkk,One thing I want to know that complex signals have one real and one imaginary part.So whether plotting on real and imaginary and theta would be in 3-D.
Or please provide me a link where I can see any complex graph plotted.

 

[wildman]

http://ccrma.stanford.edu/~jos/mdft/Complex_Plane.html

The horizonal part is the real numbers: like 1,2,3.1, etc

The vertical is the imaginary numbers. Really there is nothing imaginary about them. It is just a (stupid) name. The imaginary numbers are the square root of -1 multiplied by a real number. Needless to say, the square root of -1 doesn't exist on the real number line.

For a three D graph search for "LaPlace Transform".

 

[premagg]

thanks wildman ..
i am satisfied now..