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Perform the spectral analysis

The code in Listing 12 creates array objects to receive the results and calls the static transform method of the forwardRealToComplex01 class five times in succession to perform the spectral analysis on each of the five sinusoids.

(I will explain the transform method that performs the spectral analysis shortly.)

Only the magnitude data is displayed by this program. Therefore, the arrays that receive the other spectral analysis results from the transform method arediscarded each time a new spectral analysis is performed.

Listing 12. Perform the spectral analysis.
magnitude1 = new double[len];real = new double[len];imag = new double[len];angle = new double[len];ForwardRealToComplex01.transform(data1,real, imag,angle,magnitude1,zeroTime,lowF,highF);magnitude2 = new double[len];real = new double[len];imag = new double[len];angle = new double[len];ForwardRealToComplex01.transform(data2,real, imag,angle,magnitude2,zeroTime,lowF,highF);magnitude3 = new double[len];real = new double[len];imag = new double[len];angle = new double[len];ForwardRealToComplex01.transform(data3,real, imag,angle,magnitude3,zeroTime,lowF,highF);magnitude4 = new double[len];real = new double[len];imag = new double[len];angle = new double[len];ForwardRealToComplex01.transform(data4,real, imag,angle,magnitude4,zeroTime,lowF,highF);magnitude5 = new double[len];real = new double[len];imag = new double[len];angle = new double[len];ForwardRealToComplex01.transform(data5,real, imag,angle,magnitude5,zeroTime,lowF,highF);}//end constructor

The spectral magnitude results

Note that the magnitude results are saved in the array objects referred to by magnitude1 , magnitude2 , etc. This will be important later when I discuss the interface methods defined by Dsp028 .

The end of the constructor

Listing 12 also signals the end of the constructor. When the constructor terminates, the object has been instantiated and populated with spectralanalysis results for five sinusoids using the parameters specified by the file named Dsp028.tx t.

The getparameters method

The getParameters method used in this program is the same as that used in Dsp029 , so I won't discuss it further.

The interface methods

The Dsp028 class must define the same six interface methods as the Dsp029 class, which I discussed earlier. The only difference in the interface methods is the identification of the array objectsfrom which the methods return data when the methods are called.

The code in Listing 13 is typical of the code for methods f1 through f5 . As you can see, these methods return the data stored in the magnitude arrays. These are the spectral analysis results that areplotted in Figure 9 , Figure 11 , and later in Figure 14 .

Listing 13. The method named f1.
public double f1(double x){ int index = (int)Math.round(x);if(index<0 || index>magnitude1.length-1){ return 0;}else{ return magnitude1[index]; }//end else}//end function

The program named Graph03

The plots in Figure 9 and Figure 11 were produced by entering the following at the command line prompt:

Questions & Answers

what is math number
Tric Reply
x-2y+3z=-3 2x-y+z=7 -x+3y-z=6
Sidiki Reply
Need help solving this problem (2/7)^-2
Simone Reply
x+2y-z=7
Sidiki
what is the coefficient of -4×
Mehri Reply
-1
Shedrak
the operation * is x * y =x + y/ 1+(x × y) show if the operation is commutative if x × y is not equal to -1
Alfred Reply
An investment account was opened with an initial deposit of $9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?
Kala Reply
lim x to infinity e^1-e^-1/log(1+x)
given eccentricity and a point find the equiation
Moses Reply
12, 17, 22.... 25th term
Alexandra Reply
12, 17, 22.... 25th term
Akash
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Carole
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AJ
I am 1 year old but I can do it! 1+1=2 proof very hard for me though.
Atone
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Adu
Not really they are just easy concepts which can be understood if you have great basics. I am 14 I understood them easily.
Vedant
find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
salma
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
Abhi
If f(x) = x-2 then, f(3) when 5f(x+1) 5((3-2)+1) 5(1+1) 5(2) 10
Augustine
how do they get the third part x = (32)5/4
kinnecy Reply
make 5/4 into a mixed number, make that a decimal, and then multiply 32 by the decimal 5/4 turns out to be
AJ
how
Sheref
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
hmm
Abhi
is it a question of log
Abhi
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salma
Commplementary angles
Idrissa Reply
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Sherica
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Sherica
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Tamia
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salma
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opoku
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Ali
greetings from Iran
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hi
Nharnhar
A soccer field is a rectangle 130 meters wide and 110 meters long. The coach asks players to run from one corner to the other corner diagonally across. What is that distance, to the nearest tenths place.
Kimberly Reply
Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
August Reply
What is the expressiin for seven less than four times the number of nickels
Leonardo Reply
How do i figure this problem out.
how do you translate this in Algebraic Expressions
linda Reply
why surface tension is zero at critical temperature
Shanjida
I think if critical temperature denote high temperature then a liquid stats boils that time the water stats to evaporate so some moles of h2o to up and due to high temp the bonding break they have low density so it can be a reason
s.
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris 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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