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Compute the complex energy at each frequency

That is all there is to it. For each frequency of interest, you can use this process to compute a complexnumber, Real(F)-jImag(F), which represents the complex energy corresponding to that frequency in the target time series.

Similarly, you can compute the sum of the squares of the real and imaginary parts and consider that to be a measure of the power at that frequency in thetime series. The square root of the power is the amplitude of the energy at that frequency.

Nested for loops

Normally we are interested in more than one frequency, so we would repeat the above procedure once for each frequency of interest. This suggests the use ofnested for loops in the algorithm. The outer loop specifies the frequency of interest. The inner loop computes the sum of the products at a particularfrequency.

Description of the transform method

The static method named transform performs a real to complex Fourier transform. The method does not implement the FFT algorithm. Rather, itimplements a straightforward sampled data version of the continuous Fourier transform defined using integral calculus. (See ForwardRealToComplexFFT01 for an FFT algorithm.)

The return values

The method returns the following:

  • Real part of the spectral analysis result
  • Imaginary part of the spectral analysis result
  • Magnitude of the spectral analysis result
  • Phase angle of the spectral analysis result in degrees

The transform method parameters

The method parameters are:

  • double[] data - incoming real data
  • double[] realOut - outgoing real data
  • double[] imagOut - outgoing imaginary data
  • double[] angleOut - outgoing phase angle in degrees
  • double[] magnitude - outgoing amplitude spectrum
  • int zero - the index of the incoming data sample that represents zero time
  • double lowF - low frequency limit for computation as a fraction of sampling frequency
  • double highF - high frequency limit for computation as a fraction of sampling frequency

Frequency increment, magnitude spectrum, and number of returned values

The computational frequency increment is the difference between the high and low limits divided by the length of the magnitude array.

The magnitude or amplitude is computed as the square root of the sum of the squares of the real and imaginary parts. This value is divided by the incomingdata length, which is given by data.length .

The method returns a number of points in the frequency domain equal to the incoming data length regardless of the high and low frequency limits.

The beginning of the transform method

The class and the transform method begin in Listing 14 . The code in Listing 14 is described above.

Listing 14. The beginning of the transform method.
public class ForwardRealToComplex01{ public static void transform(double[] data,double[] realOut,double[] imagOut,double[] angleOut,double[] magnitude,int zero, double lowF,double highF){ double pi = Math.PI;//for convenienceint dataLen = data.length; double delF = (highF-lowF)/data.length;

Questions & Answers

what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
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
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
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.
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
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
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
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
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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.
what is the actual application of fullerenes nowadays?
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.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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