Hi Paul, I agree, this is confusing on the first sight. But scaling is not meant as 'scaling to' a dimension. In fact is is just a simple multiplication. The reason why it seems to work this way with 'fullsquare' and such predefined paths is, that they have a 'neutral' size/scale (bounding box size of filled path is (1pt,1pt)). Multiplying such a path with (x,y) gives an object with size (1*x,1*y). In general: if the bounding box of an object has the size (a,b) and you scale it with (x,y), the resulting object has a size of (ax,by). That's all the magic.
I must admit that this wasn't clear to me before you came up with your question. So thanks for that. :-) Best wishes, Peter Am 21.10.2011 13:38, schrieb Paul Menzel: > Am Freitag, den 21.10.2011, 01:14 +0200 schrieb Paul Menzel: >> Dear ConTeXt/MetaFun folks, >> >> >> looking at the example for grid and functions in the MetaFun manual [1] >> section 9.3 >> >> drawoptions(withpen pencircle scaled .25pt withcolor .5white) ; >> draw hlingrid(0, 20, .2, 20cm, 10cm) ; >> draw vloggrid(0, 10, .5, 10cm, 20cm) ; >> drawoptions(withpen pencircle scaled .50pt) ; >> draw hlingrid(0, 20, 1, 20cm, 10cm) ; >> draw vloggrid(0, 10, 1, 10cm, 20cm) ; >> >> fmt_pictures := false ; % use TeX as formatting engine >> textextoffset := ExHeight ; % a variable set by ConTeXt >> draw hlintext.lft(0, 20, 5, 20cm, "@3e") ; >> draw vlogtext.bot(0, 10, 9, 10cm, "@3e") ; >> >> draw >> function(1,"log(x)","x",1,10,1) xyscaled (10cm,2cm) >> withpen pencircle scaled 5mm withcolor transparent(1,.5,yellow) ; >> >> I am confused how the resulting function is scaled correctly. The >> resulting dimensions seem to be 10cm and 18 cm. So I guess the 2 cm mean >> to shift it up some how. >> >> Could someone please explain to me how `xyscaled` works in this case >> please. I though `xyscaled (αcm, ζcm)` would set the object/path to a >> width of α cm and a height of ζ cm. > > Looking up the definition of the macro `xyscaled` it is indeed just a > short version of `xscaled αcm yscaled ζcm`. > > $ more mp-tool.mp > […] > %D More robust: > > % let normalscaled = scaled ; > % let normalxscaled = xscaled ; > % let normalyscaled = yscaled ; > % > % def scaled expr s = normalscaled (s) enddef ; > % def xscaled expr s = normalxscaled (s) enddef ; > % def yscaled expr s = normalyscaled (s) enddef ; > > %D Shorter > > primarydef p xyscaled q = > begingroup ; save qq ; pair qq ; qq = paired(q) ; > ( p > if xpart qq<>0 : xscaled (xpart qq) fi > if ypart qq<>0 : yscaled (ypart qq) fi ) > endgroup > enddef ; > […] > > I am still confused though what happens in the above example scaling the > path of the function. > > Trying > > \starttext > \startMPcode > draw fullsquare xscaled 10cm yscaled 2cm; > \stopMPcode > \stoptext > > the resulting rectangle has the dimensions of 10 cm width and 2 cm > height but the path of the function above does not. > > > Thanks, > > Paul > > >> [1] http://www.pragma-ade.com/general/manuals/metafun-s.pdf >> >> >> ___________________________________________________________________________________ >> If your question is of interest to others as well, please add an entry to >> the Wiki! >> >> maillist : ntg-context@ntg.nl / >> http://www.ntg.nl/mailman/listinfo/ntg-context >> webpage : http://www.pragma-ade.nl / http://tex.aanhet.net >> archive : http://foundry.supelec.fr/projects/contextrev/ >> wiki : http://contextgarden.net >> ___________________________________________________________________________________ ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : http://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___________________________________________________________________________________