TITLE: heegard diagram 
QUESTION [7 upvotes]: It seems like there is an algorithm to find the Heegard diagram of a 3 manifold obtained by surgery on a link. Also someone told me I can find it in the Gompf and Stipciz's book. But I could not find it. Can anyone help?

REPLY [14 votes]: (1) Choose a planar presentation of your link, approximately in the plane of the blackboard.  Let $N$ be a tubular neighborhood of the link in this position.
(2) For each crossing $c$ of the presentation, add a 1-handle $T_c$ to $N$ which is perpendicular to the blackboard and connects the upper and lower parts of the crossing.  Let $H$ be the union of $N$ and all the 1-handles $T_c$.
(3) $S^3 \setminus H$ is a handlebody.  The corresponding set of Heegaard curves on $\partial H$ bijects with the complementary regions of the (flattened) planar diagram of the link.
(4) $H$ is, of course, also a handlebody.  For the corresponding Heegaard curves take the surgery curves on $N$ (this involves a choice to make them disjoint from the attaching disks of the $T_c$) union the obvious small, disk-bounding curves on the boundary of each $T_c$.  (Correction added later: Actually, if there are $k$ components of the link then one should omit $k-1$ of the $T_c$ curves.  The omitted crossings should be minimal with respect to connecting the components of the link.  Also, I'm assuming that the planar projection is a connected graph.)