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Doesn't know and doesn't care

The plotting program doesn't know, and doesn't care how the interface method decides on the value to return for each value that it receives as an incomingparameter. The plotting program simply calls the methods to get the data, and then plots the returned values.

Computed "on the fly"

For example, the returned values could be computed and returned "on the fly," as was the case in the example program named Graph01Demo , which I explained in the module titled Plotting Engineering and Scientific Data using Java .

Returned from an array

On the other hand, the values could have been computed earlier and saved in an array. That is the case with all the programs that I will explain in thismodule.

From a disk file, a database, the internet, etc.

The returned values could be read from a disk file, obtained from a databaseon another computer, or obtained from any other source such as another computer on the Internet.

All that matters is that when the plotting program calls one of the five methods named f1 through f5 , passing a double value as a parameter, it expects to receive a double value in return, and it will plot the value that it receives.

The getNmbr method

The getNmbr method for the class named Dsp029 is shown in Listing 6 .

Listing 6. The getNmbr method.
public int getNmbr(){ //Return number of functions to// process. Must not exceed 5. return numberSinusoids;}//end getNmbr

This is a very simple method. It returns the value stored in the variable named numberSinusoids . This variable may contain the default value established by Listing 1 , or may contain the value read from the file named Dsp029.txt by the method named getParameters .

The method named f1

The code for the method named f1 is shown in Listing 7 .

Listing 7. The method named f1.
public double f1(double x){ int index = (int)Math.round(x);if(index<0 || index>data1.length-1){ return 0;}else{ return data1[index]; }//end else}//end function

Note that there is not a one-to-one correspondence between horizontal coordinate values and pixels on the screen. For example, it may sometimes benecessary to plot 90 values across an area of the screen containing 110 pixels. The plotting program must interpolate properly to deal with that issue.Therefore, the plotting program deals with horizontal coordinates as type double and then converts those coordinate values to integer pixel values when the timecomes to actually draw the material on the screen.

Round from double to int

The method named f1 receives an incoming horizontal coordinate value as type double . It rounds that value to the nearest value of type long and casts it to type int to determine the index value to use when retrieving the corresponding verticalvalue from the array object.

If the index value is outside the bounds of the array, the method simply returns a value of zero. Otherwise, it uses the index value to return the valuestored in the array object at that index.

The remaining interface methods

The remaining four interface methods are identical to the method named f1 , except that each method returns data values stored in a different array object. Therefore, I won't discuss those methods.

Questions & Answers

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
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
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
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
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.
Bharti
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
Daniel
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
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
How can I make nanorobot?
Lily
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit 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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