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Figure 10. The numeric output for Case A.
Case A Real:1.0 0.923 0.707 0.382 0.0 -0.382 -0.707 -0.923 -1.0 -0.923 -0.707 -0.382 0.0 0.382 0.707 0.923imag: 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.00.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

If you plot the real and imaginary values in Figure 10 , you will see that they match the transform output shown in graphic form in Figure 9 .

Case B code

The code from the main method for Case B is shown in Listing 6 . Note that the input complex series contains non-zero values in both the real and imaginaryparts.

Listing 6. Case B code.
System.out.println("\nCase B"); double[]realInB = {0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1};double[] imagInB ={0,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,-1}; double[]realOutB = new double[16];double[] imagOutB = new double[16]; transform.doIt(realInB,imagInB,2.0,realOutB,imagOutB); display(realOutB,imagOutB);

Case B in graphical form

Case B is shown in graphical form in Figure 11 .

Figure 11. Case B in graphical form.
missing image

Case B output in numeric form

The output from the code in Listing 6 is shown in Figure 12 .

Figure 12. Case B output in numeric form.
Case B Real:1.0 0.923 0.707 0.382 0.0 -0.382 -0.707 -0.923 -0.999 -0.923 -0.707 -0.382 0.0 0.382 0.707 0.923imag: -1.0 -0.923 -0.707 -0.382 0.0 0.382 0.707 0.9231.0 0.923 0.707 0.382 0.0 -0.382 -0.707 -0.923

If you plot the values for the real and imaginary parts from Figure 12 , you will see that they match the real and imaginary output shown in Figure 11 .

Case C code

The code extracted from the main method for Case C is shown in Listing 7 .

Listing 7. Case C code.
System.out.println("\nCase C"); double[]realInC = {1.0,0.923,0.707,0.382,0.0,-0.382,-0.707,-0.923,-1.0,-0.923,-0.707,-0.382,0.0, 0.382,0.707,0.923};double[] imagInC ={0.0,-0.382,-0.707,-0.923,-1.0,-0.923, -0.707,-0.382,0.0,0.382,0.707,0.923,1.0,0.923,0.707,0.382}; double[]realOutC = new double[16];double[] imagOutC = new double[16]; transform.doIt(realInC,imagInC,16.0,realOutC,imagOutC); display(realOutC,imagOutC);

The complex input series for Case C is a little more complicated than that for either of the previous two cases. Note in particular that the input complexseries contains non-zero values in both the real and imaginary parts. In addition, very few of the values in the complex series have a value of zero.

(The values of the complex samples actually describe a cosine curve and a negative sine curve as shown in Figure 13 .)

The graphic form of Case C

Case C is shown in graphic form in Figure 13 .

Figure 13. The graphic form of Case C.
missing image

The Fourier transform is reversible

One of the interesting things to note about Figure 13 is the similarity of Figure 13 and Figure 5 . These two figures illustrate the reversible nature of the Fourier transform.

If I had used a positive input real value instead of a negative input real value in Figure 5 , the input of Figure 5 would look exactly like the output in Figure 13 , and the output of Figure 5 would look exactly like the input of Figure 13 .

With that as a hint, you should now be able to figure out how I used a mouse and drew the perfect sine and cosine curves in Figure 13 . In fact, I didn't draw them at all. Rather, I used my mouse and drew the output, andthe applet gave me the corresponding input automatically.

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
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Source:  OpenStax, Digital signal processing - dsp. OpenStax CNX. Jan 06, 2016 Download for free at https://legacy.cnx.org/content/col11642/1.38
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