Re: [Tutor] Hey guys!
On 02/16/2015 11:22 PM, Levi Adissi wrote: Thank you for using text email, rather than the html mail that so many newcomers use. So I'm kind of stuck trying to program a function that returns a list of tuples. The function takes 2 lists containing circles of which it should compare list1[0] to list2[0] to see if they intersect. If they intersect or touch then I should return them on a list of tuples(in the tuple would be both intersecting circles). I can't get circles_only to work the way I see it I'm comparing h to x only if they're both in the same place on the list (hence my "h==x") I know it doesn't work because the test returns None so I would really appreciate an alternative method if you guys see one. Here are my functions: def circles_overlap(c1, c2): x=(c2.center.y-c1.center.y)**2 y=(c2.center.x-c1.center.x)**2 distancemid=math.sqrt(x+y) distancerad=(c1.radius+c2.radius) if distancemid > distancerad: return 1 elif distancemid < distancerad: return -1 elif distancemid == distancerad: return 0 def circles_only(lst1, lst2): newlst=[] for h in lst1: for x in lst2: if h==x: That's silly. You don't want to compare the two circles to see if they're equal. Remove this line. if circles_overlap(lst1[h],lst2[x])== -1: Why don't you tell us the exception this line causes? lst1 is subscripted by integers, not by circle objects. What you really want in this line is something like: if circles_overlap(h, x) ! = 1: newlst.append(h, x) newlst.append(lst1[h],lst2[x]) elif circles_overlap(lst1[h],lst2[x])== 0: newlst.append(lst1[h],lst2[x]) print newlst Don't print it, return it. Otherwise, you're returning None. TEST CASE: def test_circles_olap1(self): list1=[data_2.Circle(data_2.Point(2,3), 2),data_2.Circle(data_2.Point(2,3), 2), data_2.Circle(data_2.Point(2,3), 2) ] list2=[data_2.Circle(data_2.Point(6,3), 2),data_2.Circle(data_2.Point(10,3), 2), data_2.Circle(data_2.Point(5,3), 2) ] testor=functions_2.circles_only(list1,list2) newlist=[(data_2.Circle(data_2.Point(2,3), 2),data_2.Circle(data_2.Point(6,3), 2)),(data_2.Circle(data_2.Point(2,3), 2),data_2.Circle(data_2.Point(10,3), 2))] self.assertEqual(testor, newlist) The test code makes no sense to me at all. it's a method of some unspecified class, and it uses some namespaces called data_2 and functions_2 for an unknown purpose. -- -- DaveA ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Hey guys!
On 17/02/15 04:22, Levi Adissi wrote: Hello. Thanks for your post. However could you please use a subject that rflects the content. Otherwise we wind up with an archive full of "Hey Guys", "Hello chaps", "Gday mate", Bonjour" etc Not very useful for searching. So I'm kind of stuck trying to program a function that returns a list of tuples. Note that your function prints the list it does not return the list. The two are very different. The function takes 2 lists containing circles of which it should compare list1[0] to list2[0] to see if they intersect. If they intersect or touch then I should return them on a list of tuples(in the tuple would be both intersecting circles). I can't get circles_only to work the way I see it I'm comparing h to x only if they're both in the same place on the list (hence my "h==x") I know it doesn't work because the test returns None so I would really appreciate an alternative method if you guys see one. Here are my functions: def circles_overlap(c1, c2): x=(c2.center.y-c1.center.y)**2 y=(c2.center.x-c1.center.x)**2 distancemid=math.sqrt(x+y) distancerad=(c1.radius+c2.radius) if distancemid > distancerad: return 1 elif distancemid < distancerad: return -1 elif distancemid == distancerad: return 0 Since this is a test you should probably just return True or False. Either they overlap or they don't. If you want to use touching as a third result you can still give a boolean for the general case: return 1 for overlap -1 for touching 0 for not touching 1 and -1 both evaluate to True in a boolean sense 0 evaluates to False This makes the test code in your second function look like: if circles_overlap(c1,c2): newlst.append((c1,c2)) and you don't need the else clause def circles_only(lst1, lst2): newlst=[] for h in lst1: for x in lst2: if h==x: Why do you have this test? You only check if they overlap when they are equal? That seems odd to me. Also h and x seem an odd choice of name for two circles. Why not for c1 in lst1: for c2 in lst2: if circles_overlap(lst1[h],lst2[x])== -1: newlst.append(lst1[h],lst2[x]) Now you are trying to use indexing to extract the circles but you are (quite rightly) iterating over the lists directly not using indexes. So h and x are circles, you don't need to get them out of the lists. Also you are trying to store two items in your newlist rather than a tuple. (See my suggested test above.) HTH -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ http://www.amazon.com/author/alan_gauld Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
[Tutor] Hey guys!
So I'm kind of stuck trying to program a function that returns a list of tuples. The function takes 2 lists containing circles of which it should compare list1[0] to list2[0] to see if they intersect. If they intersect or touch then I should return them on a list of tuples(in the tuple would be both intersecting circles). I can't get circles_only to work the way I see it I'm comparing h to x only if they're both in the same place on the list (hence my "h==x") I know it doesn't work because the test returns None so I would really appreciate an alternative method if you guys see one. Here are my functions: def circles_overlap(c1, c2): x=(c2.center.y-c1.center.y)**2 y=(c2.center.x-c1.center.x)**2 distancemid=math.sqrt(x+y) distancerad=(c1.radius+c2.radius) if distancemid > distancerad: return 1 elif distancemid < distancerad: return -1 elif distancemid == distancerad: return 0 def circles_only(lst1, lst2): newlst=[] for h in lst1: for x in lst2: if h==x: if circles_overlap(lst1[h],lst2[x])== -1: newlst.append(lst1[h],lst2[x]) elif circles_overlap(lst1[h],lst2[x])== 0: newlst.append(lst1[h],lst2[x]) print newlst TEST CASE: def test_circles_olap1(self): list1=[data_2.Circle(data_2.Point(2,3), 2),data_2.Circle(data_2.Point(2,3), 2), data_2.Circle(data_2.Point(2,3), 2) ] list2=[data_2.Circle(data_2.Point(6,3), 2),data_2.Circle(data_2.Point(10,3), 2), data_2.Circle(data_2.Point(5,3), 2) ] testor=functions_2.circles_only(list1,list2) newlist=[(data_2.Circle(data_2.Point(2,3), 2),data_2.Circle(data_2.Point(6,3), 2)),(data_2.Circle(data_2.Point(2,3), 2),data_2.Circle(data_2.Point(10,3), 2))] self.assertEqual(testor, newlist) Thanks in advance! ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
