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A Turtle object has the ability to connect two points with a straight line if, and only if, both points are inside the World object. If a point is outside the world and a turtle attempts to move to it, theturtle will behave like a dog inside a fenced yard running along the fence and barking at someone who is walking along the sidewalk on the other side of the fence. The turtle willmove along the inside boundary of the world. This is indicated by the black horizontal dotted line segments in the upper left and lower right of Figure 3 . In this case, the turtle was trying to reach a point somewhere on the extension of theblack line outside the world.

In comparison, Figure 4 shows the same lines as Figure 3 . The horizontal and vertical scaling were adjusted in Figure 4 to ensure that the end points of all three lines are inside the boundaries of the world. These lines could be drawn by a Turtle object using only the end points of the lines and only two points would be needed for eachline.

Figure 4. Line01 output with different scaling.

Missing image

In general, a turtle is incapable of reliably drawing a straight line betweentwo points if either or both the points are outside the boundaries of the world even though a line between those points would pass through the world. There area variety of ways to deal with this issue. The code that I will present below is only one of those ways.

The driver class named Line01

The driver class named Line01 is shown in Listing 15 . There is nothing new in that code so a detailed explanation should not be required.

The code in the driver class instantiates an object of the class named Line01Runner and calls an instance method named run belonging to that object. The run method is where the action is in the program.

Beginning of the class named Line01Runner

Listing 1 shows the beginning of the class named Line01Runner and the beginning of the method named run .

Listing 1 . Beginning of the class named Line01Runner. class Line01Runner{ //Instantiate the World and Turtle objects.private World world = new World(300,300); private Turtle turtle = new Turtle(0,0,world);//---------------------------------------------------------------// public void run(){//Make the turtle invisible turtle.hide();//Prepare the penturtle.setPenColor(Color.RED); turtle.setPenWidth(2);//Draw the axes in REDturtle.penUp(); turtle.moveTo(world.getWidth()/2,0);turtle.penDown(); turtle.moveTo(world.getWidth()/2,world.getHeight());turtle.penUp(); turtle.moveTo(world.getWidth(),world.getHeight()/2);turtle.penDown(); turtle.moveTo(0,world.getHeight()/2);turtle.penUp(); turtle.moveTo(0,0);

This code fragment is included here strictly for context. There is nothing in Listing 1 that you haven't seen in an earlier lesson.

The method named function for Line01

At this point, I am going to put the run method on hold and explain a method named function . This method is the heart of the program because it evaluates the standard equation of a straight line given by

y = slope*x + yIntercept

Questions & Answers

can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
I'm not sure why it wrote it the other way
I got X =-6
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
Commplementary angles
Idrissa Reply
im all ears I need to learn
right! what he said ⤴⤴⤴
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
im not good at math so would this help me
Rachael Reply
I'm not good at math so would you help me
what is the problem that i will help you to self with?
how do you translate this in Algebraic Expressions
linda Reply
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
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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