On Thu, 25 Mar 2004, Ulrich Dirr wrote:
> On occasion I need to trace TeX's page building via \tracingpages=2.
> Assume you have a \textheight of 39 \baselineskip + \topskip, and one
> \baselineskip is 13bp. Then \textheight is 507bp+10pt. Using the above
> definition for bp this should be 518.90125pt. But when tracing the
> pages I always got a pagegoal of 518.90073pt resulting often in
> underfull \vbox messages (I've hopefully eliminated all uncontrolled
> stretching and shrinking of vertical material in my setup).
> Maybe someone could explain this behavior to me?
Simple rounding errors. Internally everything is computed in scaled points
= 1/65536pt. So, your \baselineskip is
13*7227*65536 / 7200 = 855162
The textheight is then
39*855162 + 10*65536 = 34006678
In points this is
34006678/65536 = 518.90073