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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 microbiology
Nyoik Reply
microbiology is the study of micro organisms. this can be multicellular,unicellular & acellular
Janet
what is the difference between DNA/RNA
kanaaLka
DNA is a double stranded molecule while RNA is a single stranded molecule
Lovely
What are antibodies?
Happy Reply
they are immune cells that are released by immune system to fight strangers like microbes
Ahmed
a blood protien produce in response to an counteracting a specific antigen
Pooja
Why salmonella typhi is harmful protozoan?
Saily Reply
because make typhoid that is considered as a food born illness
Ahmed
Name any five modes of transmission.
Happy
what are the scientific names and common names of some microbes
Rich Reply
Staphylococcus aureus - staph Streptococcus pyogenes - strep Botulism - Clostridium botulinum Rocky Mountain spotted fever - Rickettsia rickettsii Diphtheria - Corynebacterium diphtheriae Gonorrhea - Neisseria gonorrhoeae
Tammy
what are the limitations of the Koch's postulate
Naa
how a microorganism growth.
Zubair Reply
Is foetus a parasite to his or her mother? if yes and if no ho
Mashauri Reply
y
Yusri
yes
Yashkin
yes
Zubair
yes it a parasite to the mother because it feeds on the mother for survival
Beatrice
yes
Redwan
no
Elasha
definition of a parasite: an organism that lives in or on an organism of ANOTHER species (its host) and benefits by deriving nutrients at the other's expense
Elasha
no because an organism can inky be a parasite if it causes harm to its HOST. And the fetus does not cause harm to its mother under normal conditions
aliyu
yes
Naa
what is biosensor in microbiology
Raja Reply
What are biosensor
Raja
what's are biosensor
Raja
what is microbiology defination
Rinku Reply
microbiology is the study of small or manuit organisms which cannot be seen with our nacked eyes unless with the aid of the microscope
Brandina
is the study of living organisms which are not directly visible to a direct eye but can only be seen under a microscope
Ipa
ok
Ipa
microbiology is the study of living organisms of microscopic size it is also the study of micro organisms with their form structure reproduction psychology metabolism and classification
Priyanka
ok
Aminu
Microbiology are the study of microorganisms either microscopic or sub microscopic creaters mainly unicellulars, multicellulars and subcellulars. Such as protozoa,bacteria and viruses.
Rana
it is the biological study of viruses, fungi, protozoa, bacteria which in collective name are called micro organisms, unlike microscopic organisms being invisible, that requires a magnifications with the help of a microscope.
Mohamed
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Erick Reply
don't know
SINGLE
we obtained the insulin from the bacteria. and some microorganisms are decomposer in ecosystems.
Zubair
nitrogen in the air is fixed into the soil by microbes example is nitrobactor
Matilda
yes
Zubair
how a weak immune region where microorganisms attack easily?
Zubair Reply
with examples differentiate gram positive from gram negative bacteria
Mary Reply
Differentiate gram positive from gram negative
Mary
I have no idea
Zubair
hello
Kuonain
and example of gram negative is E. coli
Pooja
gram positive stain purple when subjected to gram stain whilst gram positive bacterial has thick wall composed of peptidoglycan
Matilda
ok
Zubair
what is a process of gene expression in eukaryotes ?
Nayyab Reply
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Abdussalam
spontaneous generation means
Siddhi Reply
hiii
Siddhi
Hello
eman
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eman
I have a problem with Micro
eman
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eman
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eman
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eman
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Siddhi
good afternoon dear Friends
yaya
Greeting to everyone in here.
Manka
There is a problem. I need a diagram of a virus with it functions.
Manka
structure of bacterial
Kuyiba
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Kuonain
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suhail
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Angela
rod shape
Priyanka
helical
Priyanka
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esike
spherical
Priyanka
peomorphic
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Priyanka
hi
suhail
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DIPTI
Are we together pls what's the topic for the day?
esike
what is innate
Lizzy
innate means natural
Pooja
the genetic makeup of an individual
Matilda
pls i need the common names for the following parasites..ENTEROBIUS VERMICULARIS,NECATOR AMERICANUS,ASCARIES LUMBRICOIDES,TRICHURIS TRICHIURA,TRICHOMONAS VAGINALIS,GIARDIA LAMBLIA,ENTAMOEBA HISTOLYTICA,SCHISTOSOMA MANSONI,SCHISTOSOMAHEMATOBIUM,STROGYLOIDES STERCORALIS,AND TRAPANOSOMA BRUCI GAMBIENSE
timothy
ENTEROBIUS VERMICULARIS and STROGYLOIDES STERCORALIS have the same common name which is pin worm and thread worm
Chinedu
I didn't find the common names for TRICHOMONAS VAGINALIS, GIARDIA LAMBLIA, ENTAMOEBA HISTOLYTICA, TRYPANOSOMA BRUCEI GAMBIENSE
Chinedu
NECATOR AMERICANUS - New world hookworm ASCARIS LUMBRICOIDES- Ascarid TRICHURIS TRICHIURA- Whip worm
Chinedu
Hi guys
Chinedu
Why are myeloblasts not present in the bloodstream?
Chinedu
thank u
Dasaah
is blood from capillary puncture suitable for hormonal assays
NANCY Reply
Direct this question to a hematologist for a better answer please.
LAFIA
In most cases the blood is necessary but it's limited from my own Analysis
Lee
u can do but it depends on your sampling blood its enev or not
Ali
Control indications of cipro, doxicyclin, setracyclin, cloxacyclin, erythromycin
Oslen Reply
oo
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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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