# [Xy-pic] arrow between circles

Ross Moore ross at ics.mq.edu.au
Thu Oct 15 02:55:29 CEST 2009

Hi Pol,

On 15/10/2009, at 3:51 AM, Pol wrote:

> Hi,
>
>  I would like to draw a curved arrow connecting two circles, as a
> graphic
> view of a function.
>  This is my result:
>
> \xymatrix{ & *++[o][F]{A}\ar@(dr,dl)[rr] &  & ++[o][F]{B}}
>
>  I would like the arrow to start within the first circle and to end
> into the
> second circle.
>  Any hints?

Sure. But you have to separate the extent of the object
from the size of its frame.

e.g.
\xymatrix{ &
*[o]{A}\save*++\frm{o}\restore
\ar@(dr,dl)[rr]  & &
*+<1mm>[o]{B}\save*++\frm{o}\restore}

Note the use of  \save ... \restore
which ensures that the size of the object in a cell
is what it would be before the \save is processed.

>
> Thank you
> ---Pol

Hope this helps,

Ross

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Ross Moore                                       ross at maths.mq.edu.au
Mathematics Department                           office: E7A-419
Macquarie University                             tel: +61 (0)2 9850 8955
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