# [Rd] ugly in plotmath: frac(1, sqrt(...)) (PR#1101)

**ligges@statistik.uni-dortmund.de
**
ligges@statistik.uni-dortmund.de

*Thu, 4 Oct 2001 11:40:33 +0200 (MET DST)*

ligges@statistik.uni-dortmund.de wrote:
>*
*>* ligges@statistik.uni-dortmund.de wrote:
*>* >
*>* > Sometimes (dependent on device and settings of 'cex' and 'lwd') the line
*>* > of a square root symbol plottet in the denominator of a fraction appears
*>* > to be in or above the line of the fraction.
*>* >
*>* > Examples:
*>* >
*>* > ### Choose one of these:
*>* > # pdf("test.pdf", height=6, width=8)
*>* > # bmp("test.bmp", width=1100, height=800, pointsize=12)
*>* > # bitmap("test.tif", type="tiff24nc", width=12, height=9, res=300,
*>* > pointsize=12)
*>* > # png("test.png", width=1100, height=800, pointsize=12)
*>* > # postscript("test.eps", height=6, width=8, horizontal=FALSE)
*>* >
*>* > par(cex=2, lwd=2)
*>* > plot(1:10)
*>* > text(2, 8, expression(frac(1, sigma[i]*sqrt(2*pi))))
*>* > dev.off()
*>*
*>* After some investigations:
*>* In plotmath.c, line 2250 the "the gap between the nucleus and the
*>* radical extension" is defined:
*>* #define RADICAL_GAP 0.4
*>*
*>* It looks like this gap is not added to the hight (or included in the
*>* calculations of the hight) of the denominator of a fraction. So the
*>* whole denominator is located to close to the fraction bar, if a root is
*>* drawn.
*>* I don't see, how this can be fixed smartly ...
*
Suggestion for a fix.
plotmath.c, lines 2340 ff.:
orderBBox = CombineBBoxes(orderBBox, RenderElement(body, draw));
orderBBox = CombineBBoxes(orderBBox, RenderGap(2 * radTrail, draw));
+ orderBBox = EnlargeBBox(orderBBox, radGap, 0, 0);
SetStyle(style);
return orderBBox;
Uwe Ligges
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