[BUGZILLA #16948] mathematical label on y-axis is misaligned in X11()

[MichaelChirico]

In base graphics plot.default(), title() with the default X11() driver,
if the y-axis label 'ylab' is a mathematical expression, the components of the expression are misaligned (incorrect x coordinates).
Examples
plot(1:2, xlab=expression(f(x)), ylab=expression(g(x)))

     plot(1:2, xlab=expression(x == f(n)), ylab=expression(y == g(n)))

Does not occur in pdf() or postscript(), only in X11()

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METADATA

• Bug author - Adrian Baddeley
• Creation time - 2016-06-13 06:01:55 UTC
• Bugzilla link
• Status - NEW
• Alias - None
• Component - Graphics
• Version - R 3.3.*
• Hardware - ix86 (32-bit) Linux
• Importance - P5 minor
• Assignee - R-core
• URL -
• Modification time - 2016-06-14 20:44 UTC

[MichaelChirico]

I can confirm this on OSX. Looks like a top-right/bottom-left confusion with rotated character glyphs.

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METADATA

• Comment author - Peter Dalgaard
• Timestamp - 2016-06-13 09:32:27 UTC

[MichaelChirico]

Happens in X11(type="Xlib") but not in X11(type="cairo")

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METADATA

• Comment author - Adrian Baddeley
• Timestamp - 2016-06-14 00:50:26 UTC

[MichaelChirico]

This was a missing set of parentheses in XRotPaintAlignedString() in src/modules/X11/rotated.c

Just running some checks before committing the fix.

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METADATA

• Comment author - Paul Murrell
• Timestamp - 2016-06-14 20:44:18 UTC