# 4.7 Java1491-2d fourier transforms using java, part 2  (Page 15/21)

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## A different plotting color scheme

Note that the plotting color scheme that I used for Figure 7 is different from any of the plots previously shown in this module. This color scheme is whatI refer to as the Color Contour scheme in the module titled Plotting 3D Surfaces using Java .

This scheme quantizes the range from the lowest to the highest elevation into 23 levels, coloring the lowest elevation black, the highest elevation white, andassigning very specific colors to the 21 levels in between. The colors and the levels that they represent are shown in the calibration scales under the plotsin Figure 7 . The lowest elevation is on the left end of the calibration scale. The highest elevation is on the right end of the calibration scale.

## The amplitude spectrum

As before, the wavenumber amplitude spectrum with the origin in the top-left corner is shown in the top-right image in Figure 7 . The amplitude spectrum with the origin shifted to the center is shown in the lower right image in Figure 7 .

If you were to use the calibration scale to convert the colors along the horizontal and vertical axes in the lower right image into numeric values, youwould find that they approximate a rectified sin(x)/x shape as expected.

## The output surface

The output surface produced by performing an inverse Fourier transform on the complex wavenumber spectrum is shown in the lower-left image in Figure 7 . This surface appears to match the input surface shown in the top-left image in Figure 7 .

## The overall results

The numeric output for this case isn't very useful because none of the samples for which numeric data is provided fall within the square. However,because the real and imaginary parts exhibit the correct symmetry , , the shape of the amplitude spectrum is generally what we expect, and the output from the inverse Fouriertransform appears to match the original input causes us to conclude that the program is working properly in this case.

## Case 3

This case places a raised box at the top near the origin in the space domain, but the box is not on the diagonal as it was in Case 2.

(See the top-left image in Figure 8 for the new location of the box.)

Figure 8. Graphic output for Case 3.

## Amplitude spectrum should not change

As long as the size and the orientation of the box doesn't change, the wavenumber amplitude spectrum should be the same as Case 2 regardless of thelocation of the box in space. Since the size and orientation of this box is the same as in Case 2, the amplitude spectrum for this case should be the same asfor Case 2.

## The real and imaginary parts of the spectrum may change

However, the real and imaginary parts (or the phase) change as the location of the box changes relative to the origin in space.

## A hypothetical example

The purpose of this case is to illustrate a hypothetical example. If two different photographic images contain a picture of the same object in the samesize and the same orientation in space, that object will contribute the same values to the amplitude spectrum of both images regardless of where the objectis located in the different images.

#### Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
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
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
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
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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