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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

Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
hi
Loga
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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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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