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Listing 6. Create and save the test surface.
int rows = 41; int cols = 41;double[][]spatialData = getSpatialData(switchCase,rows,cols);

I will discuss the method named getSpatialData in detail later. For now, just assume that the 2D array object referred to by spatialData contains the test surface when this method returns.

Display the test surface

Listing 7 instantiates an object of the class named ImgMod29 to display the test surface in the display format indicated by the value of displayType .

Listing 7. Display the test surface.
new ImgMod29(spatialData,3,false,displayType);

The value of false in the third parameter indicates that the axes should not be displayed.

(See the module titled Plotting 3D Surfaces using Java for an explanation of the second parameter. Basically, this parameter is used to control the overallsize of the plot on the screen.)

An example test surface plot

The top-left image in Figure 4 is an example of the output produced by the code in Listing 7 for a displayType value of 0.

( Figure 4 shows the grayscale format. See the module titled Plotting 3D Surfaces using Java for an explanation of the three available non-logarithmic display formats.)

Figure 4. An example test surface plot.
missing image

Figure 4 shows the results for a test surface switchCase value of 2. I will discuss the particulars of this case in detail later.

Perform the forward Fourier transform

Listing 8 performs the forward Fourier transform to transform the test surface into the wavenumber domain.

Listing 8. Perform the forward Fourier transform.
double[][]realSpect = //Real part new double[rows][cols];double[][]imagSpect = //Imaginary part new double[rows][cols];double[][]amplitudeSpect = //Amplitude new double[rows][cols];ImgMod30.xform2D(spatialData,realSpect, imagSpect,amplitudeSpect);

Prepare array objects to receive the transform results

Listing 8 begins by preparing some array objects to receive the transform results. The forward transform receives an incoming surface array and returnsthe real and imaginary parts of the complex wavenumber spectrum along with the amplitude spectrum by populating three array objects passed as parameters to themethod.

Perform the forward transform

Then Listing 8 calls the static xform2D method of the ImgMod30 class to perform the forward transform, returning the results by way of the parameters to the method.

Display unshifted amplitude spectrum

The top-right image in Figure 4 is an example of the type of display produced by the code in Listing 9 . This is a plot of the amplitude spectrum without the wavenumber origin being shifted to place it at the center.

(The wavenumber origin is in the top-left corner of the top-right image in Figure 4 .)

This image also shows the result of passing true as the third parameter causing the red axes to be plotted on top of the spectral data.

Listing 9. Display unshifted amplitude spectrum.
new ImgMod29(amplitudeSpect,3,true, displayType);

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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit 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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