<< Chapter < Page
  Digital signal processing - dsp     Page 8 / 19
Chapter >> Page >

The constructor

The constructor begins in Listing 4 . The code in Listing 4 is identical to that shown earlier in Listing 2 . This code generates the five sinusoidal pulses and stores the data representing those pulses in the arrays referred to by data1 through data5 . So far, except for the declaration of some extra variables, this program isn't much different from the program named Dsp031a discussed earlier in this module.

Listing 4. Beginning of the constructor.
public Dsp031(){//constructor //Create the raw datafor(int x = 0;x<len/16;x++){ data1[x]= amp*Math.cos(2*pi*x*freq); }//end for loopfor(int x = 0;x<len/8;x++){ data2[x]= amp*Math.cos(2*pi*x*freq); }//end for loopfor(int x = 0;x<len/4;x++){ data3[x]= amp*Math.cos(2*pi*x*freq); }//end for loopfor(int x = 0;x<len/2;x++){ data4[x]= amp*Math.cos(2*pi*x*freq); }//end for loopfor(int x = 0;x<len;x++){ data5[x]= amp*Math.cos(2*pi*x*freq); }//end for loop

Perform the spectral analysis

The remainder of the constructor is shown in Listing 5 . This code calls the transform method of the ForwardRealToComplex01 class five times in succession to perform the spectral analysis on each of the five pulses shown in Figure 1 .

(I explained the transform method in detail in the previous module titled Spectrum Analysis using Java, Sampling Frequency, Folding Frequency, and the FFT Algorithm .)

Listing 5. Perform the spectral analysis.
mag1 = new double[len];real = new double[len];imag = new double[len];angle = new double[len];ForwardRealToComplex01.transform(data1,real, imag,angle,mag1,zeroTime,lowF,highF);mag2 = new double[len];real = new double[len];imag = new double[len];angle = new double[len];ForwardRealToComplex01.transform(data2,real, imag,angle,mag2,zeroTime,lowF,highF);mag3 = new double[len];real = new double[len];imag = new double[len];angle = new double[len];ForwardRealToComplex01.transform(data3,real, imag,angle,mag3,zeroTime,lowF,highF);mag4 = new double[len];real = new double[len];imag = new double[len];angle = new double[len];ForwardRealToComplex01.transform(data4,real, imag,angle,mag4,zeroTime,lowF,highF);mag5 = new double[len];real = new double[len];imag = new double[len];angle = new double[len];ForwardRealToComplex01.transform(data5,real, imag,angle,mag5,zeroTime,lowF,highF);}//end constructor

Each time the transform method is called, it computes the magnitude spectrum for the incoming data and saves it in the output array.

(Note that the real, imag, and angle arrays are not used later, so they are discarded each time a new spectral analysis is performed.)

The interface methods

The Dsp031 class also implements the interface named GraphIntfc01 . The remaining code in the program consists of the methods required to satisfy thatinterface. Except for the identification of the arrays from which the methods extract data to be returned for plotting, these methods are identical to thosedefined in the earlier class named Dsp031a . Therefore, I won't discuss them further.

Questions & Answers

How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
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.
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.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Digital signal processing - dsp. OpenStax CNX. Jan 06, 2016 Download for free at https://legacy.cnx.org/content/col11642/1.38
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Digital signal processing - dsp' conversation and receive update notifications?