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<body class='hmmessage'><div dir='ltr'>Hi!<br><br>I am trying to do an exercise abt classes, but I find it really hard even after reading. I have tryed to start it at the bottom of this document. I hope someone can help me. I have to submit the question by sunday. <br><br>Exercise 7.4. Make a class for straight lines.<br>Make a class Line whose constructor takes two points p1 and p2 (2-<br>tuples or 2-lists) as input. The line goes through these two points (see<br>function line in Chapter 3.1.7 for the relevant formula of the line). A<br>value(x) method computes a value on the line at the point x. Here is<br>a demo in an interactive session:<br><br>>>> from Line import Line<br>>>> line = Line((0,-1), (2,4))<br>>>> print line.value(0.5), line.value(0), line.value(1)<br>0.25 -1.0 1.5<br><br>My answer:<br><br>class Line:<br> def __init__(self, p1, p2):<br> self.p1 = p1<br> self.p2 = p2<br> <br> def value(self, x):<br> p1 = (y1 - y0)/float(x1 -x0) # Formula referred to in chapter 3.1.7 in the book<br> p2 = (y0 - a*x0) # return <value of the line at point x><br> <br><br>def line (x0, y0, x1, y1):<br> p1 = (x0 - x1)<br> p2 = (y0 - y1)<br> return p1, p2<br><br><br><br>Kindest Regards<br>A.F.<br><br><br><br> </div></body>
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