# [Xy-pic] half-solid ellipse

Ross Moore ross at ics.mq.edu.au
Tue Mar 29 01:30:53 CEST 2005

```Hi Aaron,

On 29/03/2005, at 4:36 AM, Aaron Lauda wrote:

> Try this:
>
> \[ \xy
> (7,0)*\ellipse(1,3){.}; (7,0)*\ellipse(1,3)_,=:a(180){-};

Yep; that's easier, giving just 2 directional arguments.

This also works, giving all 3 directional arguments:

(7,0)*\ellipse(1,3):a(-90),_,=:a(180){-};

I'm not sure why the 1st and 3rd seem to be being
interpreted differently.
Looks like I'll need to adjust the documentation
to better describe the real usage of these.

> (0,2.5)*\ellipse(1,3){-}; (0,-2.5)*\ellipse(1,3){-};
> (14,3)*{}="TR"; (14,-3)*{}="BR"; (0,8)*{}="TTL"; (0,2)*{}="TBL";
> (0,-2)*{}="BTL"; (0,-8)*{}="BBL"; (10,3)*{}="A"; (10,-3)*{}="B";
> "TTL";"A" **\crv{(5,8) & (3,4)}; "A";"TR" **\dir{-}; "BBL";"B"
> **\crv{(5,-8) & (3,-4)}; "B";"BR" **\dir{-}; "TBL";"BTL"
> **\crv{(3,2) & (3,-2)};
> \endxy \]

Cheers,

Ross

>
> Best,
> Aaron
>
> On Sun, 27 Mar 2005, Chris Brav wrote:
>
>> hi. i'm trying to make 2D cobordism diagrams. i like to draw them from
>> left to right, with solid circles on the in direction (left-hand) and
>> half-solid,
>> half-dotted circles on the out direction (right-hand), with the solid
>> half
>> "out front" and the dotted half "behind". a. lauda's code does this
>> for diagrams drawn
>> from top to bottom, but i can't get it to work from left to right.
>>
>> here is my code:
>>
>> \[ \xy
>> (7,0)*\ellipse(1,3){.};
>> (7,0)*\ellipse(1,3)__,=:a(270){-};
>> (0,2.5)*\ellipse(1,3){-};
>> (0,-2.5)*\ellipse(1,3){-};
>> (14,3)*{}="TR";
>> (14,-3)*{}="BR";
>> (0,8)*{}="TTL";
>> (0,2)*{}="TBL";
>> (0,-2)*{}="BTL";
>> (0,-8)*{}="BBL";
>> (10,3)*{}="A";
>> (10,-3)*{}="B";
>> "TTL";"A" **\crv{(5,8) & (3,4)};
>> "A";"TR" **\dir{-};
>> "BBL";"B" **\crv{(5,-8) & (3,-4)};
>> "B";"BR" **\dir{-};
>> "TBL";"BTL" **\crv{(3,2) & (3,-2)};
>> \endxy \]
>>
>> the trouble is line #3. i presume =:a() is supposed to set an angle,
>> but
>> no matter what angle i try, i can't get rid of the extra solid part
>> showing from "behind".
>>
>> any suggestions?
>>
>> chris brav
>>
>> _______________________________________________
>> xy-pic mailing list
>> http://tug.org/mailman/listinfo/xy-pic
>>
>
> _______________________________________________
> xy-pic mailing list
> http://tug.org/mailman/listinfo/xy-pic
>
------------------------------------------------------------------------
Ross Moore                                         ross at maths.mq.edu.au
Mathematics Department                             office: E7A-419
Macquarie University                               tel: +61 +2 9850 8955
Sydney, Australia                                  fax: +61 +2 9850 8114
------------------------------------------------------------------------

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