metapost line definitions 'u'
This should be a simple one, at least for Stacho and Martin B. The metapost initialise definition seems to define the value u:, which turns up in lots of other places. if BaseScale <= 1: % 1:100 u:=14bp; v:=14bp; w:=12bp; fonts_setup(8,10,12,16,24); elseif BaseScale <= 2: % 1:200 u:=12bp; v:=12bp; w:=12bp; fonts_setup(7,8,10,14,20); elseif BaseScale <= 5: % 1:500 u:=10bp; v:=10bp; w:=12bp; fonts_setup(6,7,8,10,14); else: u:=7bp; v:=14bp; w:=10bp; fonts_setup(5,6,7,8,10); fi; It seems to be a standard measure against which lots of drawn entities are measured. In the above I think 1bp = 1/72" = 0.35mm approx. Is u: (and v: w: for that matter) intended to correspond to a particular drawn entity size in the finished pdf, or are they just arbitrary variables for which one can calculate the value of, using the code in the initialise definition? Cheers Bruce
On Sun, Feb 7, 2010 at 11:29 AM, Bruce <dangle@tomo.co.nz> wrote:
Is u: (and v: w: for that matter) intended to correspond to a particular drawn entity size in the finished pdf, or are they just arbitrary variables for which one can calculate the value of, using the code in the initialise definition?
u allows nonlinear scaling of symbols depending on scale. The macro initialize assigns a fixed value to 'u' which will be used in pdf for that scale. On average, diameter of point symbols is 1u in the output. v and w behave differently (v could be used e.g. for some area fills with decreasing distance among symbols for smaller scales but only up to a certain threshold, then bigger distance again; w is almost constant). Currently they are not (or perhaps only occasionaly) used in symbols design. In the beginning we wanted to do some sort of optimization of values assigned to u, v, w but did not manage to do it so far. It would be useful if somebody could test alternative values (and alternative breaks for map scale in the initialize macro) for various scales and various styles of map drawing (lot of symbols vs. sparsely filled map). Good setup of these values could improve map appearance substantially. Cheers, Martin
participants (2)
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Bruce -
Martin Budaj