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Call the inverseXform2D method

Then Listing 11 calls the inverseXform2D method to transform the complex wavenumber spectrum into a real space function. The inverseXform2D method requires the real and imaginary parts of the complex wavenumber spectrum as input parameters.

(Note that these are the original real and imaginary parts of the complex wavenumber spectrum. They are not the versions for which the originhas been shifted for display purposes.)

The inverseXform2D method also receives an incoming array object in which to store the real result of the transform process.

Display the result of the inverse transform

Finally, Listing 12 displays the result of the inverse transform as a surface in the space domain. This surface should compare favorably with the original surface that was transformed into the wavenumber domain in Listing 8

Listing 12. Display the result of the inverse transform.
new ImgMod29(recoveredSpatialData,3,false, displayType);

The output produced by Listing 12 is shown in the lower-left image in Figure 4 . Compare this with the input surface shown in the top-left image in Figure 4 . As you can see, they do compare favorably. In fact, they appear to be identicalin this grayscale plotting format. We will see later that when a more sensitive plotting format is used, small differences in the two may become apparent.

Display some numeric results

As discussed earlier, the code in Listing 13 samples and displays a few corresponding points on the original surface and the surface produced by theinverse transform process. The results can be used to evaluate the overall quality of the process as well as the correctness of the overall scaling.

Listing 13. Display some numeric results.
for(int row = 0;row<3;row++){ for(int col = 0;col<3;col++){ System.out.println(spatialData[row][col]+ " " + recoveredSpatialData[row][col] + " ");}//col }//row}//end main

Each line of output text contains two values, and ideally the two values should be exactly the same. Realistically, because of small computational errorsin the transform and inverse transform process, it is unlikely that the two values will be exactly the same except in computationally trivial cases. Unlessthe two values are very close, however, something probably went wrong in the transform process and the results should not be trusted.

Listing 13 also signals the end of the main method.

What do we know so far?

Now we know how to use the ImgMod30 class and the ImgMod29 class to:

  • Transform a purely real 3D surface from the space domain into the wavenumber domain
  • Transform a complex wavenumber spectrum into a purely real surface in the space domain
  • Shift the origin of the real, imaginary, and amplitude wavenumber spectral parts to convert the data into a format that is more suitable forplotting
  • Plot 3D surfaces in both domains

It is time to for us to take a look at the method named getSpatialData that can be used to create any of fourteen standard surfaces in the space domain.

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
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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
Berger describes sociologists as concerned with
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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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