R-alpha: Too little cex makes you shortsighted...

Ross (ihaka@stat.auckland.ac.nz)
Fri, 20 Sep 1996 10:25:26 +1200 (NZST)


Date: Fri, 20 Sep 1996 10:25:26 +1200 (NZST)
From: Ross  <ihaka@stat.auckland.ac.nz>
Message-Id: <199609192225.KAA00150@stat.auckland.ac.nz>
To: Peter Dalgaard BSA <pd@kubism.ku.dk>
Subject: R-alpha: Too little cex makes you shortsighted...
In-Reply-To: <x2n2ym3byh.fsf@bush.kubism.ku.dk>

Peter Dalgaard writes:
 > 
 > I've just finished a set of slides on t-tests using some R-generated
 > plots. But I couldn't get the axis labels large enough. Once the plots
 > get reduced to 5in total xwidth to fit about half a transparency and
 > then further reduced for 2-up handouts, the characters have become
 > 1mm tall, even with cex=2! Larger values of cex got worse, not
 > better. 

I'm adding a ps= option to the front end so that you can nominate the
base point size for the font.

 > Looking in devPS.c, I see:
 > 
 > static void SetFont(int face, int size)
 > {
 >         if(face < 1 || face > 4) face = 1;
 >         if(size < 1 || size > 24) size = 10;
 > ...
 > 
 > This looks buggy to me. At the very least, you should supply the
 > largest or smallest pointsize, but what's the big idea of setting an
 > upper limit at all? Even at full size, 24pt (alias 8mm high capital
 > letters) is a bit low for transparencies.

After you've passed some pointers or NAs into this kind of code a few
times you start to build in protection.  I's still like an upper
bound. How about 144pt.

 > Also, it's necessary to get the mkh= parameter implemented. It's hard
 > to make a bubble plot when there's an upper limit on the symbol
 > size. (Actually, that's not what I needed; that was a big X to mark the
 > position of the average in a group of observations.)
 > 
 > And BTW: xaxt='n' has absolutely no effect currently. It'll be sorely
 > missed until it gets put in. 

Yep I know.

 > And pch='.' should probably automagically change into the plotting dot
 > pch=0, like in Splus. Currently, it gives a real period at the *bottom*
 > of a character cell centered at (x,y).

This I'm not so sure about.  Down the track (very far down the track)
I'd like to build in TeX-like capabilies for equations.  This will
mean splitting text up into smaller words and special cases for
certain one character strings may come back and bite at that point.

You have to know understand that this code was a quick hack done in a
rush two years ago, with the intent of "really doing it properly
somethime soon".  The following comment from the graphics source code
remains relevant ...

                /* GRZ-like Graphics Parameters */
                /* ``The horror, the horror ... '' */
                /* Marlon Brando - Appocalypse Now */
:-)
	Ross
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