R help - May 2012 - domain/number line/range reduction problem

Hello,

Currently I'm only coming up with brute force solutions to this issue.
Wondering if anyone knows of a better way to do this.

The problem: I have endpoints of one x range (x_rng) and an unknown number
of s ranges (s[#]_rng) also defined by endpoints. What I want are the parts
of the x ranges that don't overlap the s ranges. The examples below
demonstrate what I mean. I'm glossing over an obvious endpoint
inclusion/exclusion issue here for simplicity, but in a perfect world the
resulting ranges would not include the s range endpoints and would include
endpoints of the x range if they were not eliminated by an s range.

Is there some function(s) in R that would make this easy?

Ex 1.
For:
x_rng = c(-100,100)

s1_rng = c(-25.5,30)
s2_rng = c(0.77,10)
s3_rng = c(25,35)
s4_rng = c(70,80.3)
s5_rng = c(90,95)

I would get:
xa_rng = c(-100,-25.5)
xb_rng = c(35,70)
xc_rng = c(80.3,90)
xd_rng = c(95,100)

Ex 2.
For:
x_rng = c(-50.5,100)

s1_rng = c(-75.3,30)

I would get:
xa_rng = c(30,100)

Ex 3.
For:
x_rng = c(-75.3,30)

s1_rng = c(-50.5,100)

I would get:
xa_rng = c(-75.3,-50.5)

Ex 4.
For:
x_rng = c(-100,100)

s1_rng = c(-105,105)

I would get something like:
xa_rng = c(NA,NA)
or...
xa_rng = NA

Ex 5.
For:
x_rng = c(-100,100)

s1_rng = c(-100,100)

I would get something like:
xa_rng = c(NA,NA)
or...
xa_rng = NA

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Clarification/correction:

Ex 5 isn't consistent with the other examples....
To be consistent with the other examples the resulting ranges would be
something like:
xa_rng = c(-100,-100)
xb_rng = c(100,100)
or just...
xa_rng = -100
xb_rng = 100


However, my original Ex 5 would be a good solution if the s range endpoints
were not included in the results per my statement:
"...but in a perfect world the resulting ranges would not include the s
range endpoints and would include endpoints of the x range if they were not
eliminated by an s range."

Sorry, for any confusion.
Thanks!
Ben

On Fri, May 11, 2012 at 8:58 AM, Ben quant <ccquant@gmail.com> wrote:
> Hello,
>
> Currently I'm only coming up with brute force solutions to this issue.
> Wondering if anyone knows of a better way to do this.
>
> The problem: I have endpoints of one x range (x_rng) and an unknown number
> of s ranges (s[#]_rng) also defined by endpoints. What I want are the parts
> of the x ranges that don't overlap the s ranges. The examples below
> demonstrate what I mean. I'm glossing over an obvious endpoint
> inclusion/exclusion issue here for simplicity, but in a perfect world the
> resulting ranges would not include the s range endpoints and would include
> endpoints of the x range if they were not eliminated by an s range.
>
> Is there some function(s) in R that would make this easy?
>
> Ex 1.
> For:
> x_rng = c(-100,100)
>
> s1_rng = c(-25.5,30)
> s2_rng = c(0.77,10)
> s3_rng = c(25,35)
> s4_rng = c(70,80.3)
> s5_rng = c(90,95)
>
> I would get:
> xa_rng = c(-100,-25.5)
> xb_rng = c(35,70)
> xc_rng = c(80.3,90)
> xd_rng = c(95,100)
>
> Ex 2.
> For:
> x_rng = c(-50.5,100)
>
> s1_rng = c(-75.3,30)
>
> I would get:
> xa_rng = c(30,100)
>
> Ex 3.
> For:
> x_rng = c(-75.3,30)
>
> s1_rng = c(-50.5,100)
>
> I would get:
> xa_rng = c(-75.3,-50.5)
>
> Ex 4.
> For:
> x_rng = c(-100,100)
>
> s1_rng = c(-105,105)
>
> I would get something like:
> xa_rng = c(NA,NA)
> or...
> xa_rng = NA
>
> Ex 5.
> For:
> x_rng = c(-100,100)
>
> s1_rng = c(-100,100)
>
> I would get something like:
> xa_rng = c(NA,NA)
> or...
> xa_rng = NA
>
>
>
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