[R] Plotting only masked part of data
Joakim Hove
hove at ift.uib.no
Tue Jan 25 14:57:18 CET 2005
Hello,
I have x and y data to plot (synthetic example):
x <- seq(0,4*pi,by=0.1)
y <- sin(x)
I then want to plot (x,y) in those points where abs(y) is smaller than
0.5. As a first approximation
plot(x[abs(y) < 0.5],y[abs(y) < 0.5])
is quite close - however I want to plot with lines, i.e. type="l", and
then I get solid lines connecting the endpoint of one "active" region
to the start of the next active region, I would prefer to get rid of
those.
Lineart:
-------
_____ ____
/ (1) \ / (3)\
/ \ / \
/ \ / \
\ / \
\_____/
(2)
The problem is the horisontal lines shown as (1), (2) and (3) in the
schematic figure above, I would like to get rid of those,
i.e. retaining only four disconnected segments. I have started on a
programming based solution, plotting one piece at a time, but it is
*very* ugly!
Is there a simple general solution to my problem?
Regards
Joakim Hove
--
Joakim Hove
hove AT ift uib no
Tlf: +47 (55 5)8 27 90
Fax: +47 (55 5)8 94 40
http://www.ift.uib.no/~hove/
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